Metal cation-modified alkylation catalysts

A process for the alkylation of at least one alkene having from 2 to 6 carbon atoms with an alkane having from 4 to 6 carbon atoms to afford an alkylate of increased octane number comprising reacting in the liquid phase the alkene and alkane under alkylation conditions in the presence of a catalyst comprising:

• a) a refractory inorganic oxide, b) the reaction product of a first metal halide and bound surface hydroxyl groups of said refractory inorganic oxide, c) a second metal cation, and d) optionally a zerovalent third metal;
• where said refractory inorganic oxide is selected form the group consisting of alumina, titania, zirconia, chromia, silica, boria, silica-alumina, and combinations thereof;
• said first metal halide is a fluoride, chloride, or bromide and the first metal is selected form the group consisting of aluminum, gallium, zirconium and boron;
• said second metal cation is selected from the group consisting of i) monovalent metal cations in an amount from 0.0026 up to about 0.20 gram atoms per 100 grams refractory inorganic oxide for lithium, potassium, cesium, rubidium, silver, and copper and in an amount from 0.012 to about 0.12 gram atoms for sodium, and ii) alkaline earth metal cations in an amount from about 0.0013 up to about 0.01 gram atoms per 100 grams of refractory inorganic oxide for beryllium, strontium, and barium, and an amount from about 0.004 up to about 0.1 gram atoms per 100 grams support for magnesium and calcium;
• and any combination thereof;
• and said third metal is selected from the group consisting of platinum, palladium, nickel, ruthenium, rhodium, osmium and iridium, and any combination thereof;
• where the alkylate so formed has an increased octane number relative to alkylate formed in the absence of the second metal cation.