Silica-alumina catalysts - contg relatively high concns of alkali metals

摘要

Highly acidic silica-alumina catalysts contg. relatively large amts. (=1%) of alkali metal, but having good performances as cracking catalysts, are prepd. by a process in which a silica hydrogel is formed by aciffying an alkali metal (pref. Na) silicate to pH 5 (pref. 0.5-3.5), washed with water to alkali metal content of 2% slurried in aluminium salt (ref. Al(NO3)3) soln., excess (about 10%) ammoniacal base added, and the prod. sepd., dried and calcined. The catalyst prepd. does not require high temp. or ageing stages.