A process for preparing a zeolitic material having a framework structure type RTH
The present invention relates to a process for preparing a zeolitic material having a framework structure type RTH and having a framework structure comprising a tetravalent element Y, a trivalent element X and oxygen. Further, the present invention relates to a zeolitic material having a framework structure type RTH and having a framework structure comprising a tetravalent element Y, a trivalent element X and oxygen, obtainable or obtained by said process, and further relates to the use of said zeolitic material as a catalytically active material, as a catalyst, or as a catalyst component.
Zeolitic materials having a framework structure type RTH are known to be potentially effective as catalysts or catalyst components in industrial applications, for example for converting nitrogen oxides (NOx) in an exhaust gas stream and for converting methanol-to-olefin (MTO). Synthetic RTH zeolitic materials may generally be produced by using organic templates.
Greg S. Lee et al., “Polymethylated [4.11] Octanes Leading to Zeolite SSZ_50”, Journal of Solid State Chemistry 167, p. 289-298 (2002), describes a synthesis of such zeolitic materials which uses N-ethyl-N-methyl-5,7,7-trimethyl-azoniumbi-cyclo[4.1.1] octane cation as an organic template. However, this synthesis is expensive and accordingly not viable for wide applications.
Further, Joel E. Schmidt et al., “Facile preparation of Aluminosilicate RTH across a wide composition range using a new organic structure-directing agent”, Chemistry of Materials (ACS Publications) 26, p. 7099-7105 (2014), discloses the synthesis of RTH zeolitic material which uses imidazolium cations, and in particular pentamethylimidazolium, as an organic template and US 2017/0050858 A1 discloses a method for preparing zeolitic materials having a framework structure type RTH which uses 2,6-dimethyl-1-aza-spiro[5.4]decane cation as an organic template. However, the crystallization duration of these syntheses is of at least one day to 46 days.
Therefore, it was an object of the present invention to provide a process for preparing a zeolitic material having a framework structure type RTH and having a framework structure comprising a tetravalent element Y, a trivalent element X and oxygen which permits to reduce crystallization duration and being cost effective.
Surprisingly, it was found that the process for preparing a zeolite material having a framework structure RTH according to the present invention permits to reduce the duration of the process, in particular the crystallization duration, and to obtain zeolitic material having a framework structure type RTH with high aluminum content.
Therefore, the present invention relates to a process for preparing a zeolitic material having a framework structure type RTH and having a framework structure comprising a tetravalent element Y, a trivalent element X and oxygen, said process comprising:
wherein X is one or more of Al, B, In, and Ga.
Preferably the N-methyl-2,6-dimethylpyridinium cation containing compound is a salt, more preferably one or more of a halide, preferably iodide, chloride, fluoride and/or bromide, more preferably iodide, and a hydroxide, wherein more preferably the N-methyl-2,6-dimethylpyridinium cation containing compound is a hydroxide.
Preferably, the tetravalent element Y is Si.
Preferably, the trivalent element X is one or more of Al and B, more preferably Al. More preferably, Y is Si and X is Al.
It is preferred that the zeolitic material provided in (i) and having a framework structure type FAU is a zeolitic material selected from the group consisting of faujasite, zeolite Y, zeolite X, LSZ-210, US Y, and a mixture of two or more thereof, more preferably selected from the group consisting of zeolite Y, zeolite X and a mixture thereof, more preferably zeolite Y.
In the framework structure of the zeolitic material provided in (i), the molar ratio of Y:X, calculated as YO2: X2O3, is preferably in the range of from 5:1 to 100:1, more preferably in the range of from 10:1 to 50:1, more preferably in the range of 13:1 to 30:1, more preferably in the range of 18:1 to 28:1, more preferably in the range of from 20:1 to 27:1.
Preferably, in the synthesis mixture in (i), the molar ratio of H2O relative to Y, calculated as H2O:YO2, is in the range of from 2:1 to 80:1, more preferably in the range of from 3:1 to 50:1, more preferably in the range of from 3.5: 1 to 48: 1. More preferably, in the synthesis mixture in (i), the molar ratio of H2O relative to Y, calculated as H2O:YO2, is in the range of from 4: 1 to 45: 1. Alternatively, more preferably, in the synthesis mixture in (i), the molar ratio of H2O relative to Y, calculated as H2O:YO2, is in the range of from 3.5:1 to 6:1, more preferably in the range of from 4:1 to 5:1. Alternatively, more preferably, in the synthesis mixture in (i), the molar ratio of H2O relative to Y, calculated as H2O:YO2, is in the range of from 15:1 to 20:1, more preferably in the range of from 17:1 to 19:1. As a further alternative, more preferably, in the synthesis mixture in (i), the molar ratio of H2O relative to Y, calculated as H2O:YO2, is in the range of from 30:1 to 48:1, more preferably in the range of from 40:1 to 46:1, more preferably in the range of from 43:1 to 45:1.
In the synthesis mixture in (i), the molar ratio of the structure directing agent relative to Y, calculated as structure directing agent: YO2, is preferably in the range of from 0.09:1 to 1:1, more preferably in the range of from 0.10:1 to 0.50:1, more preferably in the range of from 0.10: 1 to 0.42: 1. More preferably, in the synthesis mixture in (i), the molar ratio of the structure directing agent relative to Y, calculated as structure directing agent: YO2, is in the range of from 0.13: 1 to 0.37: 1. Alternatively, more preferably, in the synthesis mixture in (i), the molar ratio of the structure directing agent relative to Y, calculated as structure directing agent: YO2, is in the range of from 0.10:1 to 0.18:1, more preferably in the range of from 0.12:1 to 0.16:1, more preferably in the range of from 0.13:1 to 0.15:1. Alternatively, more preferably in the synthesis mixture in (i), the molar ratio of the structure directing agent relative to Y, calculated as structure directing agent: YO2, is in the range of from 0.15:1 to 0.28:1, more preferably in the range of from 0.18:1 to 0.24:1, more preferably in the range of from 0.20:1 to 0.22:1. As a further alternative, more preferably, in the synthesis mixture in (i), the molar ratio of the structure directing agent relative to Y, calculated as structure directing agent: YO2, is in the range of from 0.30:1 to 0.42:1, more preferably in the range of from 0.33:1 to 0.39:1, more preferably in the range of from 0.35:1 to 0.37:1.
Therefore, the present invention preferably relates to a process for preparing a zeolitic material having a framework structure type RTH and having a framework structure comprising a tetravalent element Y, a trivalent element X and oxygen, said process comprising:
wherein in the framework structure of the zeolitic material provided in (i), the molar ratio of Y:X, calculated as YO2: X2O3, is in the range of from 5:1 to 100:1, more preferably in the range of from 10:1 to 50:1, more preferably in the range of 13:1 to 30:1, more preferably in the range of 18:1 to 28:1, more preferably in the range of from 20:1 to 27:1;
wherein in the synthesis mixture in (i), the molar ratio of H2O relative to Y, calculated as H2O:YO2, is in the range of from 2:1 to 80:1, more preferably in the range of from 3:1 to 50:1, more preferably in the range of from 3.5: 1 to 48: 1; and wherein in the synthesis mixture in (i), the molar ratio of the structure directing agent relative to Y, calculated as structure directing agent: YO2, is in the range of from 0.09:1 to 1:1, more preferably in the range of from 0.10:1 to 0.50:1, more preferably in the range of from 0.10: 1 to 0.42: 1.
In the context of the present invention, in the synthesis mixture in (i), the molar ratio of the source of a base relative to Y, calculated as a source of a base: YO2, is preferably in the range of from 0.02:1 to 0.32:1, more preferably in the range of from 0.04:1 to 0.30:1, more preferably in the range of from 0.06:1 to 0.30: 1.
More preferably, in the synthesis mixture in (i), the molar ratio of the source of a base relative to Y, calculated as a source of a base: YO2, is in the range of from 0.07: 1 to 0.30: 1. Alternatively, more preferably, in the synthesis mixture in (i), the molar ratio of the source of a base relative to Y, calculated as a source of a base: YO2, is in the range of from 0.06:1 to 0.10:1, more preferably in the range of from 0.07:1 to 0.09:1. As an alternative, more preferably, in the synthesis mixture in (i), the molar ratio of the source of a base relative to Y, calculated as a source of a base: YO2, is in the range of from 0.20:1 to 0.25:1, preferably in the range of from 0.21:1 to 0.23:1. As a further alternative, more preferably, in the synthesis mixture in (i), the molar ratio of the source of a base relative to Y, calculated as a source of a base: YO2, is in the range of from 0.24:1 to 0.32:1, more preferably in the range of from 0.26:1 to 0.30:1.
It is preferred that the source of a base provided in (i) comprises, more preferably is, a hydroxide. More preferably, the source of a base provided in (i) comprises, more preferably is, one or more of an alkali metal hydroxide and an alkaline earth metal hydroxide, more preferably an alkali metal hydroxide, more preferably sodium hydroxide.
Preferably, from 95 to 100 weight-%, more preferably from 98 to 100 weight-%, more preferably from 99 to 100 weight-%, more preferably from 99.5 to 100 weight-% of the synthesis mixture consist of a zeolitic material having a framework structure type FAU and having a framework structure comprising the tetravalent element Y, the trivalent element X and oxygen, water, a source of a base, and an RTH framework structure type directing agent comprising a N-methyl-2,6-dimethylpyridinium cation containing compound.
Therefore, the present invention preferably relates to a process for preparing a zeolitic material having a framework structure type RTH and having a framework structure comprising a tetravalent element Y, a trivalent element X and oxygen, said process comprising:
wherein Y is Si; wherein X is Al;
wherein in the framework structure of the zeolitic material provided in (i), the molar ratio of Y:X, calculated as YO2: X2O3, is in the range of from 5:1 to 100:1, more preferably in the range of from 10:1 to 50:1, more preferably in the range of 13:1 to 30:1, more preferably in the range of 18:1 to 28:1, more preferably in the range of from 20:1 to 27:1;
wherein in the synthesis mixture in (i), the molar ratio of H2O relative to Y, calculated as H2O:YO2, is in the range of from 2:1 to 80:1, more preferably in the range of from 3:1 to 50:1, more preferably in the range of from 3.5: 1 to 48: 1;
wherein in the synthesis mixture in (i), the molar ratio of the structure directing agent relative to Y, calculated as structure directing agent: YO2, is in the range of from 0.09:1 to 1:1, preferably in the range of from 0.10:1 to 0.50:1, more preferably in the range of from 0.10: 1 to 0.42: 1; and wherein in the synthesis mixture in (i), the molar ratio of the source of a base relative to Y, calculated as a source of a base: YO2, is in the range of from 0.02:1 to 0.32:1, more preferably in the range of from 0.04:1 to 0.30:1, more preferably in the range of from 0.06: 1 to 0.30: 1.
According to the present invention, there is no specific restriction on how the synthesis mixture is prepared in (i). Preferably, preparing a synthesis mixture in (i) comprises
As to (i.1), preparing the mixture preferably comprises stirring the mixture at a temperature of the mixture in the range of from 16 to 35° C. for a duration in the range of from 0.5 to 6 hours, more preferably at a temperature of the mixture in the range of from 20 to 30° C. for a duration in the range of from 0.75 to 4 hours, more preferably at a temperature of the mixture in the range of from 20 to 30° C. for a duration in the range of from 1.5 to 2.5 hours.
As to (i.2), preparing the synthesis mixture preferably comprises stirring the synthesis mixture at a temperature of the synthesis mixture in the range of from 16 to 35° C. for a duration in the range of from 0.5 to 6 hours, more preferably at a temperature of the synthesis mixture in the range of from 20 to 30° C. for a duration in the range of from 0.75 to 4 hours, more preferably at a temperature of the synthesis mixture in the range of from 20 to 30° C. for a duration of 1.5 to 2.5 hours.
Preferably, the hydrothermal crystallization conditions according to (ii) comprise crystallization duration in the range of from 10 minutes to 20 hours.
Preferably, the hydrothermal crystallization conditions according to (ii) comprise a crystallization temperature in the range of from 100 to 280° C. More preferably, the hydrothermal crystallization conditions according to (ii) comprise a crystallization duration in the range of from 10 minutes to 20 hours and a crystallization temperature in the range of from 100 to 280° C.
According to a first aspect of the present invention, it is preferred that the hydrothermal crystallization conditions according to (ii) comprise a crystallization temperature in the range of from 100 to 160° C. and a crystallization duration in the range of from 1 to 20 hours, more preferably a crystallization temperature in the range of from 120 to 140° C. and a crystallization duration in the range of from 10 to 14 hours, more preferably a crystallization temperature in the range of from 120 to 140° C. and a crystallization duration in the range of from 11 to 13 hours.
Therefore, the present invention preferably relates to a process for preparing a zeolitic material having a framework structure type RTH and having a framework structure comprising a tetravalent element Y, a trivalent element X and oxygen, said process comprising:
wherein Y is Si; wherein X is Al;
wherein in the framework structure of the zeolitic material provided in (i), the molar ratio of Y:X, calculated as YO2: X2O3, is in the range of from 5:1 to 100:1, more preferably in the range of from 10:1 to 50:1, more preferably in the range of 13:1 to 30:1, more preferably in the range of 18:1 to 28:1, more preferably in the range of from 20:1 to 27:1;
wherein in the synthesis mixture in (i), the molar ratio of H2O relative to Y, calculated as H2O:YO2, is in the range of from 2:1 to 80:1, more preferably in the range of from 3:1 to 50:1, more preferably in the range of from 3.5: 1 to 48: 1; and wherein in the synthesis mixture in (i), the molar ratio of the structure directing agent relative to Y, calculated as structure directing agent: YO2, is in the range of from 0.09:1 to 1:1, more preferably in the range of from 0.10:1 to 0.50:1, more preferably in the range of from 0.10: 1 to 0.42: 1;
wherein in the synthesis mixture in (i), the molar ratio of the source of a base relative to Y, calculated as a source of a base: YO2, is in the range of from 0.02:1 to 0.32:1, more preferably in the range of from 0.04:1 to 0.30:1, more preferably in the range of from 0.06: 1 to 0.30: 1;
wherein the hydrothermal crystallization conditions according to (ii) comprise a crystallization temperature in the range of from 100 to 160° C. and a crystallization duration in the range of from 1 to 20 hours, more preferably a crystallization temperature in the range of from 120 to 140° C. and a crystallization duration in the range of from 10 to 14 hours, more preferably a crystallization temperature in the range of from 120 to 140° C. and a crystallization duration in the range of from 11 to 13 hours.
According to a second aspect of the present invention, it is preferred that the hydrothermal crystallization conditions according to (ii) comprise a crystallization temperature in the range of from 160 to 200° C. and a crystallization duration in the range of from 0.5 to 10 hours, more preferably a crystallization temperature in the range of from 170 to 190° C. and a crystallization duration in the range of from 1.5 to 4.5 hours, more preferably a crystallization temperature in the range of from 170 to 190° C. and a crystallization duration of 2 to 4 hours.
Therefore, the present invention preferably relates to a process for preparing a zeolitic material having a framework structure type RTH and having a framework structure comprising a tetravalent element Y, a trivalent element X and oxygen, said process comprising:
wherein Y is Si; wherein X is Al;
wherein in the framework structure of the zeolitic material provided in (i), the molar ratio of Y:X, calculated as YO2: X2O3, is in the range of from 5:1 to 100:1, more preferably in the range of from 10:1 to 50:1, more preferably in the range of 13:1 to 30:1, more preferably in the range of 18:1 to 28:1, more preferably in the range of from 20:1 to 27:1;
wherein in the synthesis mixture in (i), the molar ratio of H2O relative to Y, calculated as H2O:YO2, is in the range of from 2:1 to 80:1, more preferably in the range of from 3:1 to 50:1, more preferably in the range of from 3.5: 1 to 48: 1; and wherein in the synthesis mixture in (i), the molar ratio of the structure directing agent relative to Y, calculated as structure directing agent: YO2, is in the range of from 0.09:1 to 1:1, more preferably in the range of from 0.10:1 to 0.50:1, more preferably in the range of from 0.10: 1 to 0.42: 1;
wherein in the synthesis mixture in (i), the molar ratio of the source of a base relative to Y, calculated as a source of a base: YO2, is in the range of from 0.02:1 to 0.32:1, more preferably in the range of from 0.04:1 to 0.30:1, more preferably in the range of from 0.06: 1 to 0.30: 1;
wherein the hydrothermal crystallization conditions according to (ii) comprise a crystallization temperature in the range of from 160 to 200° C. and a crystallization duration in the range of from 0.5 to 10 hours, more preferably a crystallization temperature in the range of from 170 to 190° C. and a crystallization duration in the range of from 1.5 to 4.5 hours, more preferably a crystallization temperature in the range of from 170 to 190° C. and a crystallization duration of 2 to 4 hours.
According to a third aspect of the present invention, it is preferred that the hydrothermal crystallization conditions according to (ii) comprise a crystallization temperature in the range of from 200 to 280° C. and a crystallization duration in the range of from 10 minutes to 3 hours, more preferably a crystallization temperature in the range of from 220 to 260° C. and a crystallization duration in the range of from 20 minutes to 90 minutes, more preferably a crystallization temperature in the range of from 220 to 260° C. and a crystallization duration in the range of from 30 to 70 minutes, more preferably a crystallization temperature in the range of from 220 to 260° C. and a crystallization duration in the range of from 40 to 60 minutes, wherein more preferably the hydrothermal crystallization conditions according to (ii) comprise a crystallization temperature in the range of from 230° C. to 250° C. and a crystallization duration in the range of from 45 to 55 minutes.
Therefore, the present invention preferably relates to a process for preparing a zeolitic material having a framework structure type RTH and having a framework structure comprising a tetravalent element Y, a trivalent element X and oxygen, said process comprising:
wherein Y is Si; wherein X is Al;
wherein in the framework structure of the zeolitic material provided in (i), the molar ratio of Y:X, calculated as YO2: X2O3, is in the range of from 5:1 to 100:1, more preferably in the range of from 10:1 to 50:1, more preferably in the range of 13:1 to 30:1, more preferably in the range of 18:1 to 28:1, more preferably in the range of from 20:1 to 27:1;
wherein in the synthesis mixture in (i), the molar ratio of H2O relative to Y, calculated as H2O:YO2, is in the range of from 2:1 to 80:1, more preferably in the range of from 3:1 to 50:1, more preferably in the range of from 3.5: 1 to 48: 1; and wherein in the synthesis mixture in (i), the molar ratio of the structure directing agent relative to Y, calculated as structure directing agent: YO2, is in the range of from 0.09:1 to 1:1, more preferably in the range of from 0.10:1 to 0.50:1, more preferably in the range of from 0.10: 1 to 0.42: 1;
wherein in the synthesis mixture in (i), the molar ratio of the source of a base relative to Y, calculated as a source of a base: YO2, is in the range of from 0.02:1 to 0.32:1, more preferably in the range of from 0.04:1 to 0.30:1, more preferably in the range of from 0.06: 1 to 0.30: 1;
wherein the hydrothermal crystallization conditions according to (ii) comprise a crystallization temperature in the range of from 200 to 280° C. and a crystallization duration in the range of from 10 minutes to 3 hours, more preferably a crystallization temperature in the range of from 220 to 260° C. and a crystallization duration in the range of from 20 minutes to 90 minutes, more preferably a crystallization temperature in the range of from 220 to 260° C. and a crystallization duration in the range of from 30 to 70 minutes, more preferably a crystallization temperature in the range of from 220 to 260° C. and a crystallization duration in the range of from 40 to 60 minutes, wherein more preferably the hydrothermal crystallization conditions according to (ii) comprise a crystallization temperature in the range of from 230° C. to 250° C. and a crystallization duration in the range of from 45 to 55 minutes.
According to the present invention, it is preferred that during the hydrothermal crystallization conditions according to (ii), the mixture obtained in (i) and subjected to (ii) is not stirred, more preferably not mechanically agitated, more preferably not agitated.
According to (ii) subjecting the synthesis mixture obtained in (i) to hydrothermal crystallization conditions is preferably carried out under autogenous pressure, more preferably in an autoclave.
Preferably, the process of the present invention further comprises
Preferably, the process of the present invention further comprises
If (iv) is performed, (iv) preferably comprises
As to (iv.2), the zeolitic material is preferably washed with water, more preferably with deionized water.
As to (iv.3), the zeolitic material is preferably dried in a gas atmosphere having a temperature in the range of from 80 to 120° C., more preferably in the range of from 90 to 110° C. More preferably, the zeolitic material is dried in a gas atmosphere having a temperature in the range of from 90 to 110° C. for a duration in the range of from 0.5 to 5 hours, more preferably the zeolitic material is dried in a gas atmosphere having a temperature in the range of from 90 to 110° C. in the range of from 1 to 3 hours, more preferably in the range of from 1.5 to 2.5 hours.
If (iv) is performed, the process of the present invention preferably further comprises
If (v) is carried out, the zeolitic material is preferably calcined in a gas atmosphere having a temperature in the range of from 400 to 650° C., more preferably in the range of from 500 to 600° C.
If (v) is carried out, the zeolitic material is preferably calcined in a gas atmosphere for a duration in the range of from 2 to 6 hours, more preferably in the range of from 3 to 5 hours. More preferably, as to (v), the zeolitic material is calcined in a gas atmosphere having a temperature in the range of from 400 to 650° C., more preferably in the range of from 500 to 600° C., for a duration in the range of from 2 to 6 hours, more preferably in the range of from 3 to 5 hours.
Therefore, the present invention preferably relates to a process for preparing a zeolitic material having a framework structure type RTH and having a framework structure comprising a tetravalent element Y, a trivalent element X and oxygen, said process comprising:
wherein Y is one or more of Si, Sn, Ti, Zr, and Ge;
wherein X is one or more of Al, B, In, and Ga.
Alternatively, if (iv) is performed, the process of the present invention preferably further comprises
If (vi) is carried out, (vi) preferably comprises
As to (vi.1), the solution comprising ammonium ions is preferably an aqueous solution comprising a dissolved ammonium salt, more preferably a dissolved inorganic ammonium salt, more preferably a dissolved ammonium nitrate.
As to (vi.1), the solution comprising ammonium ions has preferably an ammonium concentration in the range of from 0.10 to 3 mol/L, more preferably in the range of from 0.20 to 2 mol/L, more preferably in the range of from 0.5 to 1.5 mol/L.
As to (vi.1), the solution comprising ammonium ions is preferably brought in contact with the zeolitic material obtained from (iv) at a temperature of the solution in the range of from 50 to 110° C., more preferably in the range of from 60 to 100° C., more preferably in the range of from 70 to 90° C.
According to (vi.1), the solution comprising ammonium ions is preferably brought in contact with the zeolitic material obtained from (iv) for a period of time in the range of from 0.5 to 3.5 hours, more preferably in the range of from 1 to 3 hours, more preferably in the range of from 1.5 to 2.5 h. More preferably, the solution comprising ammonium ions is preferably brought in contact with the zeolitic material obtained from (iv) at a temperature of the solution in the range of from 50 to 110° C., more preferably in the range of from 60 to 100° C., more preferably in the range of from 70 to 90° C., for a period of time in the range of from 0.5 to 3.5 hours, more preferably in the range of from 1 to 3 hours, more preferably in the range of from 1.5 to 2.5 h.
According to the present invention, bringing the solution in contact with the zeolitic material according to (vi.1) preferably comprises one or more of impregnating the zeolitic material with the solution and spraying the solution onto the zeolitic material, more preferably impregnating the zeolitic material with the solution.
If (vi.1) is carried out, (vi) preferably comprises
According to the present invention, if (vi) is performed, (vi.1) and (vi.2) are preferably carried out at least once, more preferably twice.
If (vi.2) is carried out, (vi) preferably comprises
As to (vi.3), the solution comprising ions of one or more transition metals is preferably an aqueous solution comprising a dissolved salt of one or more transition metals, more preferably a dissolved organic copper salt, more preferably a dissolved copper acetate.
As to (vi.3), the solution comprising ions of one or more transition metals has preferably a transition metal concentration, more preferably a copper concentration, in the range of from 0.10 to 3 mol/L, more preferably in the range of from 0.20 to 2 mol/L, more preferably in the range of from 0.5 to 1.5 mol/L.
According to (vi.3), the solution comprising ions of one or more transition metals is preferably brought in contact with the zeolitic material obtained from (vi.2) at a temperature of the solution in the range of from 20 to 80° C., more preferably in the range of from 30 to 70° C., more preferably in the range of from 40 to 60° C.
According to (vi.3), the solution comprising ions of one or more transition metals is preferably brought in contact with the zeolitic material obtained from (vi.2) for a period of time in the range of from 0.5 to 3.5 hours, more preferably in the range of from 1.0 to 3.0 hours, more preferably in the range of from 1.5 to 2.5 hours. More preferably, according to (vi.3), the solution comprising ions of one or more transition metals is brought in contact with the zeolitic material obtained from (vi.2) at a temperature of the solution in the range of from 20 to 80° C., more preferably in the range of from 30 to 70° C., more preferably in the range of from 40 to 60° C., for a period of time in the range of from 0.5 to 3.5 hours, more preferably in the range of from 1.0 to 3.0 hours, more preferably in the range of from 1.5 to 2.5 hours.
If (vi.3) is carried out, (vi) preferably comprises
If (vi.2) or (vi.4) is carried out, the process of the present invention preferably further comprises (vii) ageing the zeolitic material obtained in (vi.2), more preferably in (vi.4), in gas atmosphere.
As to (vii), ageing is preferably performed in gas atmosphere, more preferably in air, having a temperature in the range of from 600 to 900° C. for a duration in the range of from 14 to 18 hours, more preferably a temperature in the range of from 700 to 800° C. for a duration in the range of from 15 to 17 hours.
Therefore, the present invention preferably relates to a process for preparing a zeolitic material having a framework structure type RTH and having a framework structure comprising a tetravalent element Y, a trivalent element X and oxygen, said process comprising:
wherein Y is one or more of Si, Sn, Ti, Zr, and Ge;
wherein X is one or more of Al, B, In, and Ga.
The present invention further relates to a process for preparing a molding comprising a zeolitic material obtained or obtainable by a process, for preparing a zeolitic material having a framework structure type RTH and having a framework structure comprising a tetravalent element Y, a trivalent element X and oxygen, according to the present invention and optionally a binder material.
Preferably, the process comprises
There is no particular restriction with respect to the source of binder material used in the mixture according to (a). Preferably, the source of a binder material is one or more of a source of graphite, silica, titania, zirconia, alumina, and a mixed oxide of two or more of silicon, titanium and zirconium.
According to (a), the mixture preferably further comprises one or more of a pasting agent and a pore forming agent.
Preferably, subjecting to shaping according to (b) comprises subjecting the mixture prepared according to (a) to spray-drying, to spray-granulation, to tableting or to extrusion, more preferably to tableting.
The present invention further relates to a process for preparing a molding comprising
There is no particular restriction with respect to the source of binder comprised in the mixture according to (a.2). Preferably, the source of a binder material is one or more of a source of graphite, silica, titania, zirconia, alumina, and a mixed oxide of two or more of silicon, titanium and zirconium.
Preferably, the mixture prepared according to (a) further comprises one or more of a pasting agent and a pore forming agent.
Preferably, subjecting to shaping according to (b) comprises subjecting the mixture prepared according to (a.2) to spray-drying, to spray-granulation, to tableting, or to extrusion.
According to the present invention, it is preferred that the gas atmosphere comprises, more preferably is, one or more of air, lean air, and oxygen, more preferably air.
The present invention further relates to a zeolitic material having a framework structure type RTH and having a framework structure which comprises a tetravalent element Y, a trivalent element X and oxygen, wherein Y is one or more of Si, Sn, Ti, Zr, and Ge and wherein X is one or more of Al, B, In, and Ga.
Preferably, the tetravalent element Y is Si and the trivalent element X is one or more of Al and B, more preferably X is Al.
Preferably, in the framework structure of the zeolitic material, the molar ratio of Y:X, calculated as a YO2: X2O3, is in the range of from 2: 1 to 25:1, more preferably the molar ratio is in the range of from 2:1 to 24:1, more preferably of from 10:1 to 23:1, more preferably of from 15:1 to 21:1, more preferably in the range of from 15.5: 1 to 20: 1, more preferably of from 16:1 to 19:1.
Preferably, the zeolitic material of the present invention has a BET specific surface area, determined as described in Reference Example 1 b), in the range of from 100 to 800 m2/g, more preferably of from 300 to 700 m2/g, more preferably of from 400 to 600 m2/g, more preferably of from 500 to 600 m2/g.
Preferably, the zeolitic material of the present invention has a N2 micropore volume, determined as described in Reference Example 1 b), in the range of from 0.05 to 0.60 cm3/g, more preferably of from 0.10 to 0.50 cm3/g, more preferably of from 0.15 to 0.35 cm3/g, more preferably of from 0.20 to 0.30 cm3/g.
Preferably, the zeolitic material of the present invention exhibits a cuboid morphology, determined as described in Reference Example 1 d), wherein the cubes having edges the longest of which more preferably having a length in the range of from 0.2 to 2 micrometer, more preferably of from 0.2 to 1.5 micrometer.
Preferably, the zeolitic material of the present invention has a crystallinity in the range of from 80 to 100%, more preferably of from 90 to 100%, more preferably of from 99 to 100%, more preferably of 100%, determined as described in Reference Example 1 a) and g).
Preferably, the zeolitic material of the present invention has an X-ray diffraction pattern comprising at least the following reflections:
wherein 100% relates to the intensity of the maximum peak in the X-ray powder diffraction pattern, more preferably having an X-ray diffraction pattern comprising at least the following reflections:
wherein 100% relates to the intensity of the maximum peak in the X-ray powder diffraction pattern.
It is preferred that the zeolitic material of the present invention additionally comprises one or more transition metals, more preferably one or more of Cu and Fe, more preferably Cu. More preferably, the elemental metal amount of the one or more transition metals, more preferably one or more of Cu and Fe, more preferably Cu, is in the range of from 0.5 to 6.0 weight-%, preferably in the range of from 1.0 to 5.0 weight-%, more preferably in the range of from 1.5 to 4.0 weight-%, more preferably in the range of from 2.0 to 3.5 weight-% based on the total weight of the zeolitic material, calculated as elemental Cu or Fe.
The zeolitic material of the present invention which preferably additionally comprises one or more transition metals, more preferably one or more of Cu and Fe, more preferably Cu, has more preferably a BET specific surface area, determined as described in reference Example 1 b), in the range of from 100 to 800 m2/g, more preferably from 300 to 700 m2/g, more preferably from 400 to 600 m2/g, more preferably from 450 to 550 m2/g.
The zeolitic material of the present invention which preferably additionally comprises one or more transition metals, more preferably one or more of Cu and Fe, more preferably Cu, has more preferably a N2 micropore volume, determined as described in reference Example 1 b), in the range of from 0.05 to 0.60 cm3/g, preferably from 0.10 to 0.50 cm3/g, more preferably from 0.15 to 0.35 cm3/g, more preferably from 0.20 to 0.30 cm3/g.
The present invention further relates to a zeolitic material having a framework structure type RTH and having a framework structure which comprises a tetravalent element Y, a trivalent element X and oxygen, obtainable or obtained or preparable or prepared by a process for preparing a zeolitic material having a framework structure type RTH and having a framework structure comprising a tetravalent element Y, a trivalent element X and oxygen according to the present invention, wherein Y is one or more of Si, Sn, Ti, Zr, and Ge and wherein X is one or more of Al, B, In, and Ga.
Preferably, the tetravalent element Y is Si and the trivalent element X is one or more of Al and B, more preferably X is Al.
Preferably, in the framework structure of the zeolitic material obtained or obtainable by a process according to the present invention, the molar ratio of Y:X, calculated as a YO2: X2O3, is in the range of from 2: 1 to 25:1, more preferably the molar ratio is in the range of from 2:1 to 24:1, more preferably of from 10:1 to 23:1, more preferably of from 15:1 to 21:1, more preferably in the range of from 15.5: 1 to 20: 1, more preferably of from 16:1 to 19:1.
Preferably, the zeolitic material of the present invention has a BET specific surface area, determined as described in Reference Example 1 b), in the range of from 100 to 800 m2/g, more preferably of from 300 to 700 m2/g, more preferably of from 400 to 600 m2/g, more preferably of from 500 to 600 m2/g.
Preferably, the zeolitic material of the present invention has a N2 micropore volume, determined as described in Reference Example 1 b), in the range of from 0.05 to 0.60 cm3/g, more preferably of from 0.10 to 0.50 cm3/g, more preferably of from 0.15 to 0.35 cm3/g, more preferably of from 0.20 to 0.30 cm3/g.
Preferably, the zeolitic material of the present invention exhibits a cuboid morphology, determined as described in Reference Example 1 d), wherein the cubes having edges the longest of which more preferably having a length in the range of from 0.2 to 2 micrometer, more preferably of from 0.2 to 1.5 micrometer.
Preferably, the zeolitic material of the present invention has a crystallinity in the range of from 80 to 100%, more preferably of from 90 to 100%, more preferably of from 99 to 100%, more preferably of 100%, determined as described in Reference Example 1 a) and g).
Preferably, the zeolitic material of the present invention has an X-ray diffraction pattern comprising at least the following reflections:
wherein 100% relates to the intensity of the maximum peak in the X-ray powder diffraction pattern, more preferably having an X-ray diffraction pattern comprising at least the following reflections:
wherein 100% relates to the intensity of the maximum peak in the X-ray powder diffraction pattern.
It is preferred that the zeolitic material of the present invention additionally comprises one or more transition metals, more preferably one or more of Cu and Fe, more preferably Cu. More preferably, the elemental metal amount of the one or more transition metals, more preferably one or more of Cu and Fe, more preferably Cu, is in the range of from 0.5 to 6.0 weight-%, preferably in the range of from 1.0 to 5.0 weight-%, more preferably in the range of from 1.5 to 4.0 weight-%, more preferably in the range of from 2.0 to 3.5 weight-% based on the total weight of the zeolitic material, calculated as elemental Cu or Fe.
The zeolitic material of the present invention which preferably additionally comprises one or more transition metals, more preferably one or more of Cu and Fe, more preferably Cu, has more preferably a BET specific surface area, determined as described in reference Example 1 b), in the range of from 100 to 800 m2/g, more preferably from 300 to 700 m2/g, more preferably from 400 to 600 m2/g, more preferably from 450 to 550 m2/g.
The zeolitic material of the present invention which preferably additionally comprises one or more transition metals, more preferably one or more of Cu and Fe, more preferably Cu, has more preferably a N2 micropore volume, determined as described in reference Example 1 b), in the range of from 0.05 to 0.60 cm3/g, more preferably from 0.10 to 0.50 cm3/g, more preferably from 0.15 to 0.35 cm3/g, more preferably from 0.20 to 0.30 cm3/g.
The present invention further relates to a use of a zeolitic material according to the present invention as a catalytically active material, as a catalyst, or as a catalyst component. Preferably, the use of said zeolitic material is for the selective catalytic reduction of nitrogen oxides in an exhaust gas stream of a diesel engine. Or, the use of said zeolitic material is preferably for converting methanol to one or more olefins.
The present invention further relates to a use of a molding obtained or obtainable by a process for preparing a molding according to the present invention as a catalyst, preferably for the selective catalytic reduction of nitrogen oxides in an exhaust gas stream of a diesel engine or preferably for converting methanol compounds to one or more olefins.
The present invention further relates to a method for selectively catalytically reducing nitrogen oxides in an exhaust gas stream of a diesel engine, said method comprising bringing said exhaust gas stream in contact with a molding, preferably obtained or obtainable by a process for preparing a molding according to the present invention, comprising the zeolitic material according to the present invention comprising one or more transition metals, more preferably one or more of Cu and Fe, more preferably Cu.
The present invention further relates to a method for converting methanol compounds to one or more olefins, said method comprising bringing said compounds in contact with a molding, preferably obtained or obtainable by a process for preparing a molding according to the present invention, comprising the zeolitic material according to the present invention comprising one or more transition metals, more preferably one or more of Cu and Fe, more preferably Cu.
The present invention further relates to a method for selectively catalytically reducing nitrogen oxides in an exhaust gas stream of a diesel engine, said method comprising preparing a zeolitic material having a framework structure type RTH and having a framework structure which comprises a tetravalent element Y, a trivalent element X, and oxygen obtained or obtainable by a process for preparing a zeolitic material having a framework structure type RTH and having a framework structure comprising a tetravalent element Y, a trivalent element X and oxygen according to the present invention, and bringing said exhaust gas stream in contact with a catalyst comprising said zeolitic material.
The present invention further relates to a catalyst, preferably for selectively catalytically reducing nitrogen oxides in an exhaust gas stream of a diesel engine, or preferably for catalytically converting methanol to one or more olefins, said catalyst comprising the zeolitic material according to the present invention comprising one or more transition metals, more preferably one or more of Cu and Fe, more preferably Cu.
The present invention is illustrated by the following set of embodiments and combinations of embodiments resulting from the dependencies and back-references as indicated. In particular, it is noted that in each instance where a range of embodiments is mentioned, for example in the context of a term such as “The process of any one of embodiments 1 to 4”, every embodiment in this range is meant to be explicitly disclosed for the skilled person, i.e. the wording of this term is to be understood by the skilled person as being synonymous to “The process of any one of embodiments 1, 2, 3 and 4”.
H2O relative to Y, calculated as H2O:YO2, is in the range of from 3.5:1 to 6:1, preferably in the range of from 4:1 to 5:1.
wherein 100% relates to the intensity of the maximum peak in the X-ray powder diffraction pattern, preferably having an X-ray diffraction pattern comprising at least the following reflections:
wherein 100% relates to the intensity of the maximum peak in the X-ray powder diffraction pattern.
The present invention is further illustrated by the following examples, reference examples, and comparative examples.
0.1 mol of 2,6-dimethyl-pyridine and 0.12 mol of iodomethane (CH3I) was dissolved in 20 g of ethanol. The mixture was then heated to 80° C. (353 K) and stirred for 12 hours in a dark place. The solvent and the excess of iodomethane were removed using rotary evaporation and the product was washed with ether.
The structure was verified using 13C and 1H NMR as shown in
Finally, the product was converted from the iodide form to the hydroxide form using anion exchange resin to obtain N-methyl-2,6-dimethylpyridinium hydroxide. 130 g of structure directing agent were obtained.
Materials:
1 g of zeolite Y was mixed with 5.83 g of N-methyl-2,6-dimethylpyridinium hydroxide solution (0.6 mol·L−1) and stirred at room temperature for 2 hours. Then, 0.15 g of NaOH was added. The synthesis mixture was stirred again at room temperature for 2 hours. The synthesis mixture composition was 0.11 Na2O:0.21 SDA:1.0 SiO2:0.04 Al2O3:17.8 H2O. The term SiO2 refers to the silicon comprised in the zeolite Y calculated as silica. The obtained mixture was then transferred in a Teflon-lined autoclave oven. The autoclave was sealed and the mixture crystallized at 130° C. under static state for 12 hours. After pressure release and cooling to room temperature, the obtained suspension was subjected to filtration. The filter cake was washed with deionized water and was then dried for 2 hours at a temperature of 100° C. 0.8 g of zeolitic material was obtained.
The SiO2:Al2O3 molar ratio of the zeolitic material was of 17.6. The XRD patterns, determined as described in reference Example 1 a), of the dried zeolitic material show series of peaks associated with the RTH framework structure type, namely a peak at 10.16 2Theta, a peak at 18.86 2Theta, a peak at 23.24 2Theta, a peak at 25.10 2Theta, a peak at 25.55 2Theta and a peak at 30.63 2Theta, as shown in
c) Preparing the H-form of a zeolitic material having a framework structure type RTH
The zeolitic material obtained from b) is ion-exchanged with a 1M NH4NO3 solution at 80° C. for 2 hours and calcined at 550° C. for 4 hours. The procedure was repeated once.
d) Preparing the Cu-form of a zeolitic material having a framework structure type RTH
The H-form zeolitic material obtained from c) was ion-exchanged with 1 M Cu(CH3COO)2 aqueous solution at 50° C. for 2 hours and calcined at 550° C. for 4 hours.
Copper content (Cu) of the Cu-exchanged RTH zeolitic material: 2.7 weight-%, calculated as elemental Cu, based on the total weight of the zeolitic material. The thermal analysis TG-DTA of the respectively obtained fresh RTH zeolitic material is shown in
Example 2: Preparation of a Zeolitic Material having a Framework Structure Type RTH (Varying the Crystallization Temperature and Duration)
a) Preparing a zeolitic material having a framework structure type RTH
Materials:
1 g of zeolite Y was mixed with 5.83 g of N-methyl-2,6-dimethylpyridinium hydroxide solution (0.6 mol·L−1) and stirred at room temperature for 2 hours. Then, 0.15 g of NaOH was added. The synthesis mixture was stirred again at room temperature for 2 hours. The synthesis mixture composition was 0.11 Na2O:0.21 SDA:1.0 SiO2:0.04Al2O3:17.8 H2O. The term SiO2 refers to the silicon comprised in the zeolite Y calculated as silica. The obtained mixture was then transferred in a Teflon-lined autoclave oven. The autoclave was sealed and the mixture crystallized at 180° C. under static state for 3 hours. After pressure release and cooling to room temperature, the obtained suspension was subjected to filtration. The filter cake was washed with deionized water and was then dried for 2 hours at a temperature of 100° C. 0.8 g of zeolitic material was obtained.
The SiO2: Al2O3 molar ratio of the zeolitic material was of 17.8. The crystallinity of the sample was of 100%, determined as described in Reference Example 1 g), as shown in
b) Preparing the H-form of a zeolitic material having a framework structure type RTH
The zeolitic material obtained from a) is ion-exchanged with a 1M NH4NO3 solution at 80° C. for 2 hours and calcined at 550° C. for 4 hours. The procedure was repeated once.
c) Preparing the Cu-form of a zeolitic material having a framework structure type RTH
The H-form zeolitic material obtained from b) was ion-exchanged with 1 M Cu(CH3COO)2 aqueous solution at 50° C. for 2 hours and calcined at 550° C. for 4 hours.
Copper content (Cu) of the Cu-exchanged RTH zeolitic material: 3.3 weight-%, calculated as elemental Cu, based on the total weight of the zeolitic material. The XRD patterns of the respectively obtained fresh Cu-RTH zeolitic material show the characteristic peaks of the RTH framework structure, namely a peak at around 10 2Theta, a peak at around 18 2Theta, a peak at around 23 2Theta, two peaks from 24.5 to 26 2Theta, a peak around 30 2Theta, wherein the peak at 18 2Theta and the two peaks from 24.5 to 26 2Theta exhibit the highest intensities, as shown in
a) Preparing a zeolitic material having a framework structure type RTH
Materials:
1 g of zeolite Y was mixed with 5.85 g of N-methyl-2,6-dimethylpyridinium hydroxide solution (0.6 mol·L−1) and stirred at room temperature for 2 hours. Then, 0.15 g of NaOH powder was added. The synthesis mixture was stirred again at room temperature for 2 hours. The synthesis mixture composition was 0.11 Na2O:0.21 SDA:1.0 SiO2:0.04Al2O3:17.8 H2O. The term SiO2 refers to the silicon comprised in the zeolite Y calculated as silica. The obtained mixture was then transferred in a Teflon-lined autoclave oven. The autoclave was sealed and the mixture crystallized at 240° C. for 50 minutes under static state. After pressure release and cooling to room temperature, the obtained suspension was subjected to filtration. The filter cake was washed with deionized water and was then dried for 2 hours at a temperature of 100° C. 0.8 g of zeolitic material was obtained.
The SiO2: Al2O3 molar ratio of the zeolitic material was of 17.7. The crystallinity of the sample was of 100%, determined as described in Reference Example 1 g), as shown in
b) Preparing the H-form of a zeolitic material having a framework structure type RTH
The zeolitic material obtained a) is ion-exchanged with a 1M NH4NO3 solution at 80° C. for 2 hours and calcined at 550° C. for 4 hours. The procedure was repeated once.
c) Preparing the Cu-form of a zeolitic material having a framework structure type RTH
The H-form zeolitic material obtained from b) was ion-exchanged with 1 M Cu(CH3COO)2 aqueous solution at 50° C. for 2 hours and calcined at 550° C. for 4 hours.
Copper content of the Cu-exchanged RTH zeolitic material: 3.4 weight-%, calculated as elemental Cu, based on the total weight of the zeolitic material. The XRD patterns of the respectively obtained fresh Cu-RTH zeolitic material show a peak at around 10 2Theta, a peak at around 18 2Theta, a peak at around 23 2Theta, two peaks from 24.5 to 26 2Theta, a peak around 30 2Theta, wherein the peak at 18 2Theta and the two peaks from 24.5 to 26 2Theta exhibit the highest intensities, as shown in
Comparative Example 1: Preparation of a Zeolitic Material having a RTH-Type Framework Structure using an Organic Structure Directing Agent According to the Prior Art
a) Preparing an organic structure directing agent: 1,2,3-trimethylimidazolium hydroxide
0.1 mol of 1,2-dimethylimidazole and 0.1 mol of iodomethane (CH31) was dissolved in 20 g of ethanol. The mixture was stirred at room temperature for 48 hours in a dark place. The solvent and the excess of iodomethane were removed using rotary evaporation and the product was washed with ether. The structure was verified using 1H NMR as shown in
b) Trying to prepare a zeolitic material having a framework structure type RTH
Materials:
1 g of zeolite Y was mixed with 5.85 g of 1,2,3-trimethylimidazolium hydroxide solution (0.6 mol·L−1) and stirred at room temperature for 2 hours. Then, 0.20 g of NaOH was added. The synthesis mixture was stirred again at room temperature for 2 hours. The synthesis mixture composition was 0.15 Na2O:0.21 SDA:1.0 SiO2:0.04 Al2O3:17.8 H2O. The term SiO2 refers to the silicon comprised in the zeolite Y calculated as silica. The obtained mixture was then transferred in a Teflon-lined autoclave oven. The autoclave was sealed and the mixture is crystallized at 130° C. for 96 hours under static state. After pressure release and cooling to room temperature, the obtained suspension was subjected to filtration. The filter cake was washed with deionized water and was then dried for 2 hours at a temperature of 100° C. 0.8 g of zeolitic material was obtained.
The product obtained was a RTH zeolitic material having a SiO2:Al2O3 molar ratio of 18. The XRD patterns of the respectively obtained fresh zeolitic material show a peak at around 10 2Theta, a peak at around 18 2Theta, a peak at around 23 2Theta, two peaks from 24.5 to 26 2Theta, a peak around 30 2Theta which is characteristic of RTH framework structure as shown in
Materials:
1 g of zeolite Y was mixed with 5.83 g of N-methyl-2,6-dimethylpyridinium hydroxide solution (0.6 mol·L−1) and stirred at room temperature for 2 hours. The synthesis mixture composition was 0.21 SDA:1.0 SiO2:0.04 Al2O3:18 H2O. The term SiO2 refers to the silicon comprised in the zeolite Y calculated as silica. The obtained mixture was then transferred in a Teflon-lined autoclave oven. The autoclave was sealed and the mixture crystallized at 130° C. for 24 hours under static state. After pressure release and cooling to room temperature, the obtained suspension was subjected to filtration. The filter cake was washed with deionized water and was then dried for 2 hours at a temperature of 100° C.
The product obtained was a zeolite Y. The XRD patterns of the respectively obtained zeolitic material show the characteristic peaks of zeolite Y, namely a peak at around 6 2Theta, a peak at around 16 2Theta, a peak at around 20 2Theta, a peak at around 23 2Theta, a peak around 27 2Theta, as shown in
Comparative Example 2 shows that a base, in particular a strong base such as NaOH, is an essential compound for synthesizing a zeolitic material having a framework structure type RTH according to the present invention. In particular, conducting the reaction procedure without a strong base leads to no reaction.
Comparative Example 3: Attempt to Prepare a Zeolitic Material Having a Framework Structure Type RTH using a Different Molar Ratio of the Base to Silica
Materials:
1 g of zeolite Y was mixed with 5.83 g of N-methyl-2,6-dimethylpyridinium hydroxide solution (0.6 mol·L−1) and stirred at room temperature for 2 hours. Then, 0.25 g of NaOH powder was added. The synthesis mixture was stirred again at room temperature for 2 hours. The synthesis mixture composition was 0.18 Na2O:0.21 SDA:1.0 SiO2:0.04 Al2O3:18 H2O. The term SiO2 refers to the silicon comprised in the zeolite Y calculated as silica. The obtained mixture was then transferred in a Teflon-lined autoclave oven. The autoclave was sealed and the mixture crystallized at 130° C. for 24 hours under static state. After pressure release and cooling to room temperature, the obtained suspension was subjected to filtration. The filter cake was washed with deionized water and was then dried for 2 hours at a temperature of 100° C.
The product obtained was a mixture of zeolite Y and a RTH zeolitic material. The XRD patterns of the respectively obtained zeolitic material show characteristic peaks of RTH framework structure, namely a peak at around 10 2Theta, a peak at around 18 2Theta, a peak at around 23 2Theta, two peaks from 24.5 to 26 2Theta, a peak around 30 2Theta, and of zeolite Y, namely a peak at around 6 2Theta, a peak at around 16 2Theta, a peak at around 20 2Theta, a peak at around 23 2Theta, a peak around 27 2Theta, as shown in
Comparative Example 3 shows that the amount of the base, such as NaOH, is essential for synthesizing a zeolitic material having a framework structure type RTH according to the present invention. In particular, conducting the reaction procedure at an amount of base, preferably NaOH, outside of the inventive range leads to a mixture of a RTH zeolitic material and starting material.
Comparative Example 4: Attempt to Prepare a Zeolitic Material Having a Framework Structure Type RTH without a Template
Materials:
1 g of zeolite Y was mixed with 0.15 g of NaOH in deionized water and stirred at room temperature for 2 hours. The synthesis mixture composition was 0.11 Na2O:1.0 SiO2:0.04 Al2O3:18 H2O. The term SiO2 refers to the silicon comprised in the zeolite Y calculated as silica. The obtained mixture was then transferred in a Teflon-lined autoclave oven. The autoclave was sealed and the mixture crystallized at 130° C. for 24 hours under static state. After pressure release and cooling to room temperature, the obtained suspension was subjected to filtration. The filter cake was washed with deionized water and was then dried for 2 hours at a temperature of 100° C.
The product obtained was amorphous. The XRD patterns of the respectively obtained product are characteristic of amorphous product as shown in
Comparative Example 4 shows that a structure directing agent is an essential compound for synthesizing a zeolitic material having a framework structure type RTH according to the present invention. In particular, conducting the reaction procedure without a structure directing agent leads to amorphous products.
Comparative Example 5: Attempt to prepare a zeolitic material having a RTH-type framework structure using a different molar ratio of water to silica
Materials:
1 g of zeolite Y was mixed with 5.83 g of N-methyl-2,6-dimethylpyridinium hydroxide solution (0.6 mol·L−1) in deionized water, 20 g of deionized water was added and stirred at room temperature for 2 hours. Then, 0.15 g of NaOH powder was added. The synthesis mixture was stirred again at room temperature for 2 hours. The synthesis mixture composition was 0.11 Na2O: 0.21 SDA: 1.0 SiO2:0.04 Al2O3:84.5 H2O. The term SiO2 refers to the silicon comprised in the zeolite Y calculated as silica. The obtained mixture was then transferred in a Teflon-lined autoclave oven. The autoclave was sealed and the mixture crystallized at 130° C. for 24 hours under static state. After pressure release and cooling to room temperature, the obtained suspension was subjected to filtration. The filter cake was washed with deionized water and was then dried for 2 hours at a temperature of 100° C.
The product obtained was a mixture of zeolite Y and a RTH zeolitic material. The XRD patterns of the respectively obtained zeolitic material show characteristic peaks of RTH framework structure and of zeolite Y, namely a peak at around 6 2Theta, a peak at around 16 2Theta, a peak at around 20 2Theta, a peak at around 23 2Theta, a peak around 27 2Theta, as shown in
Comparative Example 5 shows that the amount of water is essential for synthesizing a zeolitic material having a framework structure type RTH according to the present invention. In particular, conducting the synthesis procedure with an amount of water outside of the inventive range leads to a mixture of a RTH zeolitic material and starting material.
Comparative Example 6: Attempt to Prepare a Zeolitic Material Having a Framework Structure Type RTH using a Zeolite Y Having a Different Molar Ratio of Silica to Alumina
Materials:
1 g of zeolite Y was mixed with 5.83 g of N-methyl-2,6-dimethylpyridinium hydroxide solution (0.6 mol·L−1) in deionized water and stirred at room temperature for 2 hours. Then, 0.15 g of NaOH powder was added. The synthesis mixture was stirred again at room temperature for 2 hours. The synthesis mixture composition was 0.11 Na2O: 0.14 SDA: 1.0 SiO2:0.083 Al2O3:18 H2O. The term SiO2 refers to the silicon comprised in the zeolite Y calculated as silica. The obtained mixture was then transferred in a Teflon-lined autoclave oven. The autoclave was sealed and the mixture crystallized at 130° C. for 24 hours under static state. After pressure release and cooling to room temperature, the obtained suspension was subjected to filtration. The filter cake was washed with deionized water and was then dried for 2 hours at a temperature of 100° C.
The product obtained was a zeolite Y. The XRD patterns of the respectively obtained zeolitic material show the characteristic peaks of zeolite Y, namely a peak at around 6 2Theta, a peak at around 16 2Theta, a peak at around 20 2Theta, a peak at around 23 2Theta, a peak around 27 2Theta, as shown in
Comparative Example 6 shows that the SiO2:Al2O3 molar ratio of the starting material is essential for synthesizing a zeolitic material having a framework structure type RTH according to the present invention. In particular, conducting the reaction procedure, with a SiO2:Al2O3 molar ratio outside of the inventive range, leads to no reaction.
Example 4: Use of the Zeolitic Material Having a Framework Structure Type RTH for Selectively Catalytically Reducing Nitrogen Oxides
Catalysts comprising the zeolitic materials respectively obtained from Examples 1, 2 and 3 were prepared and subjected to a selective catalytic reduction test by tableting and squash to 40-60 mesh. The amount of catalysts used in the fixed bed is 0.5 g each.
For this purpose, the catalytic activities of the respectively obtained fresh catalysts were measured with a fixed-bed quartz continuous reactor (the length of the reactor is 30 cm, and its internal diameter is 4 mm) in gaseous mixture containing 500 ppm of NO, 500 ppm of NH3, 10% of 02 and N2 as a balance gas. The gas hourly space velocity (GHSV) was 80 000 h−1 at temperatures of the feed stream of 100 to 600° C. The inlet and outlet gases were monitored by FTIR (Nicolet iS50 equipped with 2 m gas cell and a DTGS detector, resolution: 0.5 cm−1, OPD velocity: 0.4747 cm s−1). The collected region was 600-4000 cm-1 and the number of scans per spectrum was 16 times. The results are displayed in
The catalysts comprising the zeolitic material obtained from Examples 1 to 3 exhibit NOx conversions of greater than 90% across the temperature range of from 200 to 400° C. for the respectively obtained fresh catalysts. The respectively obtained fresh catalyst comprising a zeolitic material obtained from Example 1 (sample a in
After ageing at 750° C., the catalyst comprising a zeolitic material obtained from Example 1 (sample d in
For preparing the RTH zeolitic materials of Examples 5 to 10, the process of Example 1 has been repeated except that the ratios outlined in Table 1 below have been applied.
The respectively obtained materials were zeolitic materials having a framework structure RTH.
The XRD patterns of the respectively obtained material of Example 5 show the characteristic peaks of zeolite RTH, namely 10 2Theta, a peak at around 18 2Theta, a peak at around 23 2Theta, two peaks from 24.5 to 26 2Theta, a peak around 30 2Theta, as shown in
The XRD patterns of the respectively obtained material of Example 6 show the characteristic peaks of zeolite RTH, namely 10 2Theta, a peak at around 18 2Theta, a peak at around 23 2Theta, two peaks from 24.5 to 26 2Theta, a peak around 30 2Theta, as shown in
The XRD patterns of the respectively obtained material of Example 7 show the characteristic peaks of zeolite RTH, namely 10 2Theta, a peak at around 18 2Theta, a peak at around 23 2Theta, two peaks from 24.5 to 26 2Theta, a peak around 30 2Theta, as shown in
The XRD patterns of the respectively obtained material of Example 8 show the characteristic peaks of zeolite RTH, namely 10 2Theta, a peak at around 18 2Theta, a peak at around 23 2Theta, two peaks from 24.5 to 26 2Theta, a peak around 30 2Theta, as shown in
The XRD patterns of the respectively obtained material of Example 9 show the characteristic peaks of zeolite RTH, namely 10 2Theta, a peak at around 18 2Theta, a peak at around 23 2Theta, two peaks from 24.5 to 26 2Theta, a peak around 30 2Theta, as shown in
The XRD patterns of the respectively obtained material of Example 10 show the characteristic peaks of zeolite RTH, namely 10 2Theta, a peak at around 18 2Theta, a peak at around 23 2Theta, two peaks from 24.5 to 26 2Theta, a peak around 30 2Theta, as shown in
Number | Date | Country | Kind |
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PCT/CN2018/075433 | Feb 2018 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN2019/072687 | 1/22/2019 | WO | 00 |