Abstract: A method for preparing an alumina having controlled pore volume distribution is disclosed. The method requires the presence of 0.1-15% by weight of a water soluble aliphatic polycarboxylic acid having from 2-12 carbon atoms based on the dry weight of Al.sub.2 O.sub.3, during alumina precipitation. The resultant calcined alumina has a pore volume distribution such that:A. Nitrogen desorption measurements indicate that less than 10% of the total pores as determined by said method fall between 100-1200A in diameter;B. Nitrogen adsorption measurements indicate that between 10-50% of the total pore volume as determined fall between 100-1200A in diameter; andC. Mercury penetration porisimetry indicates that less than 10% of the total pores as determined by both nitrogen desorption and mercury methods fall between 100-50,000A in diameter.

Abstract: Silica-alumina powders can be extruded into catalyst supports having improved properties by the addition of up to 15% by weight of a polycarboxylic acid, containing 2-10 carbon atoms, based on the dry weight of the powder to the silica-alumina powders prior to extrusion. The addition of the polycarboxylic acid also increases the extrusion rate.

Abstract: Alumina-phosphorous powders can be extruded into catalysts supports having improved properties by the addition of up to 15% by weight of a polycarboxylic acid, containing 2-10 carbon atoms, based on the dry weight of the alumina-phosphorous powder prior to extrusion. The addition of the polycarboxylic acid also increases the extrusion rate.

Abstract: A novel phospha-alumina gel having a large average pore diameter and a characteristic pore volume distribution is prepared by co-precipitation of aluminum and phosphorus compounds. The gel is then dried, formed and calcined to give a material having a large average pore diameter of at least 100 A and a characteristic pore volume distribution with a minimum number of small pores, such that less than 30% of the total pore volume is in pores smaller than 100 A in diameter. Such material is especially useful as a catalyst or as a catalyst support.