Roger F. Vogel

Alumina-aluminum phosphate as a large-pore support and its application to liquid phase hydrogenation

Abstract Studies were conducted on the preparation of several compositions of alumina-aluminum phosphate and their resulting physical properties. It was observed that by varying the stoichiometry of the precipitates, surface areas and pore size distributions could be controlled. High alumina content invariably yielded materials with high surface area and small pores while high aluminum phosphate resulted in smaller surface area and larger pores. Some of the large-pore support gels were mixed with nickel salts to produce catalysts which were found to be highly active for the liquid phase hydrogenation of 2-ethylhexenal. The relative activities were successfully correlated with catalyst average pore radii and surface areas.

The gas-phase hydrogenation of benzene using phosphate-supported nickel catalysts

The gas-phase hydrogenation of benzene was studied on a series of nickel catalysts supported on alumina-aluminum phosphate (AAP), magnesia-alumina-aluminum phosphate (MgAAP), SiO/sub 2/, and kieselguhr. Measurements of the reaction rates at 110/sup 0/C 3.5 atm, and GHSV = 42,000 showed the phosphate-supported Ni catalysts to be less active than catalysts supported on SiO/sub 2/ or kieselguhr. Additionally, the relative rate on Ni/MgAAP was dependent on the reduction temperature employed during pretreatment. Comparison of the hydrogenation rates and the sulfur capacity toward thiophene poisoning versus the irreversible hydrogen uptake of the various catalysts indicated that the reduced activity of phosphate-supported Ni was due to metal-support effects and that only sites which exhibited strong hydrogen chemisorption were active for benzene hydrogenation.