Described are compositions adapted to catalyze the vapor phase dehydrohalogenation of 1,1,2-trihaloethane to 1,1-dihaloethylene, e.g., 1,1,2-trichloroethane to vinylidene chloride. These materials include activated carbon and at least one benzimidazole-containing material defined herein as including benzimidazole, a derivative thereof, a salt thereof or mixtures thereof. Also described are methods for producing and using these catalytic compositions.