METHOD OF PREPARING A CONTROLLED PORE VOLUME ALUMINA WITH CITRIC ACID

摘要

A method for preparing an alumina having controlled pore volume distribution is disclosed. The method requires the presence of 0.1 to 15% by weight of a water soluble aliphatic polycarboxylic acid having from 4 - 22 carbon atoms and of 0.5% to 4.0% of sodium silicate, both based on the dry weight of Al2O3, 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 - 1200.ANG. in diameter; B. Nitrogen absorption measurements indicate that between 10 - 50% of the total pore volume as determined fall between 100 - 1200.ANG. in diameter; and C. Mercury penetration porisimetry indicates that less than 10% of the total pores as determined by both nitrogen desorption and mercury methods fall between 100 - 50,000.ANG. in diameter. These materials find use as catalyst supports, for example in hydrodesulfurization procedures.