Shaped extrudate of phosphoric acid catalyst utilizable for the conversion of organic compounds

A solid catalyst composite which consists of a shaped extrudate comprising a solid binder admixed with phosphoric acid is provided in a form having a ratio of exterior surface area to catalyst volume greater than where D is the largest representative diameter of the extrudate and L is the length of said extrudate. This solid composite is useful in reactions involving the conversion of organic compounds where the catalyst particles swell during the course of the reaction due to the formation of coke because its configuration permit a sufficient amount of voidage in the catalyst bed to be maintained thus avoiding or postponing a shut-down due to pressure drop problems.