| abstract |
A dense, attrition resistant catalyst is prepared by precipitating a silica alumina hydrogel at high pH, and subsequently reacting the alkaline hydrogel with sufficient acid aluminum salt at a pH below 4 to obtain an acidic hydrogel slurry. The slurry is then processed into a catalyst by spray drying, washing and ion exchanging. The catalyst may include substantial quantities of clay and/or crystalline aluminosilicate zeolites. |