Dehydrogenation method using sulfided nonacidic multimetallic catalyst

A method for dehydrogenating a dehydrogenatable hydrocarbon comprising contacting the hydrocarbon at dehydrogenation conditions with a sulfided nonacidic catalytic composite comprising a porous carrier material consisting essentially of, on an elemental basis, about 0.01 to about 2 wt. % platinum or palladium, about 0.01 to about 2 wt. % iridium, about 0.1 to about 5 wt. % alkali metal or alkaline earth metal, about 0.01 to about 5 wt. % tin or lead, and about 0.01 to about 1 wt. % sulfur;

• wherein the platinum or palladium, iridium, alkali metal or alkaline earth metal and tin or lead are uniformly dispersed throughout the porous carrier material;
• wherein substantially all of the platinum or palladium and iridium are present in a sulfided state or in a mixture of the elemental metallic state and the sulfided state;
• wherein substantially all of the tin or lead and alkali metal or alkaline earth metal are present in an oxidation state above that of the elemental metal;
• and wherein the composite has been sulfided, prior to contact with any hydrocarbon and after substantially all of the platinum or palladium and iridium contained therein have been reduced to the corresponding elemental metallic state, by treatment with a sulfiding gas at conditions selected to incorporate about 0.01 to about 1 wt. % sulfur.