Claims
- 1. Process for manufacture of an attrition resistant catalyst having an oxide-rich surface layer comprising the steps of:a) forming a slurry comprising; i) catalyst, catalyst precursor or catalyst support particles, ii) a colloidal oxide sol wherein oxide particles in the sol have an average particle size greater than 10 nm; and, iii) a solution of a solvent and solute wherein the solute is selected from the group consisting essentially of a precursor of said oxide-rich surface layer with average particle size no greater than 5 nm, a colloidal oxide sol wherein oxide particles in the sol have an average size below 10 nm, and mixtures thereof, wherein 50 to 95 percent of the weight of the oxide-rich surface layer is derived from said colloidal oxide sol (ii) and remaining 50 to 5 percent of the weight of the oxide-rich surface layer is derived from the solute of said solution (iii), and wherein 3 to 15 percent weight of the attrition resistant catalyst is from the oxide-rich surface layer and the remainder is from said catalyst, catalyst precursor or catalyst support particles (i); b) spray drying the slurry from step (a) to form porous microspheres of the attrition resistant catalyst; and c) calcining the spray dried microspheres of step (b) to produce attrition resistant catalyst.
- 2. The process of claim 1 wherein said support particles are a vanadium/phosphate oxide catalyst precursor, said colloidal oxide sol is a silica sol and said solution of solute and solvent is an aqueous polysilicic acid solution.
CROSS-REFERENCE TO RELATED APPLICATIONS
Applicants claim the benefit of priority to provisional application 60/109,403 filed Nov. 20, 1998.
US Referenced Citations (4)
Provisional Applications (1)
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Number |
Date |
Country |
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60/109403 |
Nov 1998 |
US |