Composite oxide support, catalyst for low temperature water gas shift reaction and methods of preparing the same

Abstract

A composite oxide support containing ceria and an oxide of M1(M1 being Al, Zr or Ti) such that the atomic ratio of cerium to M1 is in the range of 1:4 to 1:40; a method of preparing the composite oxide support; a catalyst for low temperature water gas shift reaction, having a transition metal active component supported on the composite oxide support by an incipient wetness method; and a method of preparing the catalyst for low temperature water gas shift reaction are provided. The catalyst for low temperature water gas shift reaction prepared by using the composite oxide support can effectively remove carbon monoxide from the hydrogen produced from the low temperature water gas shift reaction at a lower temperature with a higher carbon monoxide conversion rate, compared with conventional catalysts for water gas shift reaction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a block diagram for illustrating stages of fuel processing in a fuel processor used in fuel cell systems;

FIG. 2 is a block diagram for illustrating a method of preparing a composite oxide support according to an embodiment of the present invention;

FIG. 3 is a block diagram for illustrating a method of preparing a low temperature water gas shift reaction catalyst according to an embodiment of the present invention; and

FIG. 4A and FIG. 4B are graphs showing the test results for the carbon monoxide removal performance of the supported catalysts prepared in Examples 1 and 2 and Comparative Example 3 of embodiments of the present invention.

Claims

1. A composite oxide support, comprising ceria (CeO2) and an oxide of M1 such that the atomic ratio of cerium (Ce) in the ceria to M1 is in the range of 1:4 to 1:40, wherein M1 is at least one metal selected from aluminum (Al), zirconium (Zr) and titanium (Ti).

2. The composite oxide support of claim 1, wherein the amount of the ceria in the composite oxide support is 3 to 20% by weight, based on the total weight of the composite oxide support.

3. The composite oxide support of claim 1, wherein the oxide of M1 is alumina (Al2O3).

4. The composite oxide support of claim 1, wherein the composite oxide support has a specific surface area of 20 m2/g to 1,500 m2/g.

5. A method of producing a composite oxide support, comprising: dissolving a ceria (CeO2) precursor in a mixed solvent of an alcohol-based solvent and an acid to obtain a first oxide precursor solution;dissolving at least one metal oxide precursor selected from alumina (Al2O3) precursors, zirconia (ZrO2) precursors and titania (TiO2) precursors in a mixed solvent of an alcohol-based solvent and an acid to obtain a second oxide precursor solution;mixing and heating the first oxide precursor solution and the second oxide precursor solution to form a solution mixture in a gel state; andcalcining the resulting solution mixture in the gel state to obtain the composite oxide support.

6. The method of claim 5, wherein the ceria precursor includes at least one selected from the group consisting of Ce(NO3)3.6H2O, Ce(CH3CO2)3, Ce(CO3)3, CeCl3, (NH4)2Ce(NO3)6, (NH4)2Ce(SO4)4, Ce(OH)4, Ce2(C2O4)3, Ce(ClO4)3 and Ce2(SO4)3; The alumina precursor includes at least one selected from the group consisting of Al(NO3)3.9H2O, AlCl3, Al(OH)3, AlNH4(SO4)2.12H2O, Al((CH3)2CHO)3, Al(CH3CH(OH)CO2)2, Al(ClO4)3.9H2O, Al(C6H5O)3, Al2(SO4)3.18H2O, Al(CH3(CH2)3O)3, Al(C2H5CH(CH3)O)3Al and Al(C2H5O)3, the zirconia precursor includes at least one selected from the group consisting of ZrO(NO3)2, ZrCl4, Zr(OC(CH3)3)4, Zr(O(CH2)3CH3)4, (CH3CO2)Zr(OH), ZrOCl2, Zr(SO4)2, and Zr(OCH2CH2CH3)4; and the titania precursor includes at least one selected from the group consisting of Ti(NO3)4, TiOSO4, Ti(OCH2CH2CH3)4, Ti(OCH(CH3)2)4, Ti(OC2H5)4, Ti(OCH3)4, TiCl3, Ti(O(CH2)3CH3)4 and Ti(OC(CH3)3)4.

7. The method of claim 5, wherein the calcining is performed at a temperature of 400° C. to 700° C.

8. The method of claim 5, wherein the weight ratio of the ceria precursor, the alcohol-based solvent and the acid in the first oxide precursor solution is in the range of 1:10:2 to 1:80:20.

9. The method of claim 5, wherein the weight ratio of the at least one metal oxide precursor selected from alumina precursors, zirconia precursors and titania precursors; the alcohol-based solvent; and the acid in the second oxide precursor solution, is in the range of 1:10:2 to 1:80:20.

10. The method of claim 5, wherein the alcohol-based solvent is a monohydric alcohol having 1 to 10 carbon atoms, or a dihydric alcohol having 1 to 10 carbon atoms.

11. The method of claim 5, wherein the mixing and heating of the first oxide precursor solution and the second oxide precursor solution to form the solution mixture in the gel state, is performed at a temperature of 100° C. to 200° C.

12. The method of claim 5, wherein the atomic ratio of cerium in the ceria precursor to the metal component in the at least one metal oxide precursor selected from alumina precursors, zirconia precursors and titania precursors, is in the range of 1:4 to 1:40.

13. A low temperature water gas shift reaction catalyst, comprising: a composite oxide support comprising ceria (CeO2) and an oxide of M1 such that the atomic ratio of cerium in the ceria to M1 is in the range of 1:4 to 1:40, wherein M1 is at least one metal selected from aluminum (Al), zirconium (Zr) and titanium (Ti); anda transition metal active component supported on the composite oxide support.

14. The low temperature water gas shift reaction catalyst of claim 13, wherein the proportion of the transition metal active component is 1 to 10% by weight, based on the total weight of the low temperature water gas shift reaction catalyst.

15. The low temperature water gas shift reaction catalyst of claim 13, wherein the transition metal active component is in the form of particles and wherein the degree of dispersion of the particles of the transition metal active component is 60% or greater.

16. The low temperature water gas shift reaction catalyst of claim 13, wherein the transition metal active component is platinum (Pt), or an alloy of platinum with palladium (Pd), nickel (Ni), cobalt (Co), ruthenium (Ru), rhenium (Re), rhodium (Rh), osmium (Os), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), copper (Cu), cerium(Ce) or zinc (Zn).

17. The low temperature water gas shift reaction catalyst of claim 13, wherein the proportion of the ceria is 3 to 20% by weight, based on the total weight of the composite oxide support.

18. The low temperature water gas shift reaction catalyst of claim 13, wherein the oxide of M1 is alumina (Al2O3).

19. The low temperature water gas shift reaction catalyst of claim 13, wherein the composite oxide support has a specific surface area of 20 m2/g to 1,500 m2/g.

20. A method of producing a low temperature water gas shift reaction catalyst, comprising: dissolving a ceria (CeO2) precursor in a mixed solvent of an alcohol-based solvent and an acid to obtain a first oxide precursor solution;dissolving at least one metal oxide precursor selected from alumina (Al2O3) precursors, zirconia (ZrO2) precursors and titania (TiO2) precursors in a mixed solvent of an alcohol-based solvent and an acid to obtain a second oxide precursor solution;mixing and heating the first oxide precursor solution and the second oxide precursor solution to form a solution mixture in a gel state;calcining the solution mixture in the gel state to produce a composite oxide support;impregnating a transition metal active component into the composite oxide support by an incipient wetness method to obtain an impregnation product; andcalcining the impregnation product to obtain the low temperature water gas shift reaction catalyst.

21. The method of claim 20, wherein the calcining of the impregnation product is performed at a temperature of 300° C. to 700° C.

22. The method of claim 20, wherein the ceria precursor includes at least one selected from the group consisting of Ce(NO3)3.6H2O, Ce(CH3CO2)3, Ce(CO3)3, CeCl3, (NH4)2Ce(NO3)6, (NH4)2Ce(SO4)4, Ce(OH)4, Ce2(C2O4)3, Ce(ClO4)3 and Ce2(SO4)3 the alumina precursor includes at least one selected from the group consisting of Al(NO3)3.9H2O, AlCl3, Al(OH)3, AlNH4(SO4)2.12H2O, Al((CH3)2CHO)3, Al(CH3CH(OH)CO2)2, Al(ClO4)3 .9H2O, Al(C6H5O)3, Al2(SO4)3.18H2O, Al(CH3(CH2)3O)3, Al(C2H5CH(CH3)O)3Al and Al(C2H5O)3; the zirconia precursor includes at least one selected from the group consisting of ZrO(NO3)2, ZrCl4, Zr(OC(CH3)3)4, Zr(O(CH2)3CH3)4, (CH3CO2)Zr(OH), ZrOCl2, Zr(SO4)2, and Zr(OCH2CH2CH3)4; and the titania precursor includes at least one selected from the group consisting of Ti(NO3)4, TiOSO4, Ti(OCH2CH2CH3)4, Ti(OCH(CH3)2)4, Ti(OC2H5)4, Ti(OCH3)4, TiCl3, Ti(O(CH2)3CH3)4and Ti(OC(CH3)3)4.

23. The method of claim 20, wherein the calcining of the solution mixture in the gel state is performed at a temperature of 400° C. to 700° C.

24. The method of claim 20, wherein the weight ratio of the ceria precursor, the alcohol-based solvent and the acid in the first oxide precursor solution is in the range of 1:10:2 to 1:80:20.

25. The method of claim 20, wherein the weight ratio of the at least one metal oxide precursor selected from alumina precursors, zirconia precursors and titania precursors; the alcohol-based solvent; and the acid in the second oxide precursor solution is in the range of 1:10:2 to 1:80:20.

26. The method of claim 20, wherein the alcohol-based solvent is a monohydric alcohol having 1 to 10 carbon atoms, or a dihydric alcohol having 1 to 10 carbon atoms.

27. The method of claim 20, wherein the mixing and heating of the first oxide precursor solution and the second oxide precursor solution to form the solution mixture in the gel state, is performed at a temperature of 100° C. to 200° C.

28. The method of claim 20, wherein the atomic ratio of cerium in the ceria precursor to the metal component in the at least one metal oxide precursor selected from alumina precursors, zirconia precursors and titania precursors, is in the range of 1:4 to 1:40.

29. A method of removing carbon monoxide from a gas containing carbon monoxide, comprising contacting the low temperature water gas shift reaction catalyst of claims 13 with the gas containing carbon monoxide.

30. The method of claim 29, wherein the contacting is performed at a temperature of 200° C. to 280° C.

31. A fuel processor containing the composite oxide support of claim 1.

32. A fuel processor including an apparatus for a low temperature water gas shift reaction comprising a low temperature water gas shift reaction catalyst comprising the composite oxide support of claim 1.

33. A fuel processor containing a single water gas shift reaction reactor, wherein the single water gas shift reaction reactor comprises a water gas shift reaction catalyst comprising the composite oxide support of claim 1.

34. A fuel cell system comprising a fuel stack and a fuel processor, wherein the fuel processor contains the composite oxide support of claim 1.

35. A fuel cell system comprising a fuel stack and a fuel processor, wherein the fuel processor includes an apparatus for a low temperature water gas shift reaction that comprises a low temperature water gas shift reaction catalyst that comprises the composite oxide support of claim 1.

36. A fuel cell system comprising a fuel stack and a fuel processor, wherein the fuel processor contains a single water gas shift reaction reactor, wherein the single water gas shift reaction reactor comprises a water gas shift reaction catalyst comprising the composite oxide support of claim 1.