EFFECT OF PROMOTERS AND REACTANT CONCENTRATION ON THE SELECTIVE OXIDATION OF N-BUTANE TO MALEIC-ANHYDRIDE USING VANADIUM PHOSPHORUS OXIDE CATALYSTS

The role of promoters and reactant concentration on the selective oxidation of n-butane to maleic anhydride is reviewed for vanadium phosphorus oxide catalysts. It is considered that the promoters have a twofold structural role: (a) to enable the formation of the required VPO compounds and decrease the formation of deleterious phases, and (b) to enable the formation of solid solutions which regulate the catalytic activity of the solid. Studies on the effect of reactant concentration have indicated that considerable advantages can be gained for maleic anhydride yields by using increased n-butane concentrations, but as yet few studies have been made in this area.