A dual component cracking catalyst system is disclosed comprising zeolite as a first component and a mixture of a calcium/magnesium-containing material and a magnesium-containing material as a second component. The preferred calcium/magnesium-containing material is dolomite and the preferred magnesium-containing...http://www.google.com.au/patents/US4988654?utm_source=gb-gplus-sharePatent US4988654 - Dual component cracking catalyst with vanadium passivation and improved sulfur tolerance
