Abstract: The invention relates to a process for the preparation of catalysts or catalyst additives by kneading and/or grinding, spray-drying and heat-treating a suspension containing a catalytically active component as well as aluminum hydroxide and/or one or more aluminum hydroxy compound(s) and other binding agent(s) and optionally kaolin(ite), which comprises using one or more aluminum-containing silicic acid modification(s) of formula (I),H.sub.4+y-z ?(SiO.sub.4/2).sub.x-y (AlO.sub.4/2).sub.y (SiO.sub.3/2 O).sub.4-z (AlO.sub.3/2).sub.z !, (I)wherein y is less than 1; z is less than 1; and x is 0, 4, 10, or 16 to 18, instead of the kaolin(ite) or a part thereof to be used as filling material. The process and the catalysts or catalyst additives render it possible to increase the butene fraction of cracked products.