Synthesis of bulk and alumina-supported bimetallic carbide and nitride catalysts

A new synthesis for the preparation of the bimetallic carbide, Co3Mo3C, as well as syntheses for the preparation of alumina-supported Ni2Mo3N, Co3Mo3N, and Co3Mo3C are described. The syntheses utilize the temperature-programmed reduction (TPR) method in which solid-state precursors are converted to the desired products in the presence of gas-phase reactants. Bulk and alumina-supported Co3Mo3C is prepared in a two-step synthesis in which oxide precursors are converted to Co3Mo3N, which is subsequently carburized to give the bimetallic carbide. Alumina-supported Ni2Mo3N and Co3Mo3N are prepared from supported oxide precursors via nitridation in flowing NH3, while the carburization of bulk and alumina-supported Co3Mo3N utilizes a CH4/H-2 mixture to yield the bimetallic carbide products. Elemental analysis of a 22.5 wt % Co3Mo3C/Al2O3 catalyst suggests incomplete replacement of N with C under the synthesis conditions employed. The alumina-supported carbide and nitride materials have high surface areas and O-2 chemisorption capacities, suggesting that these syntheses provide an excellent route for the preparation of heterogeneous catalysts in which bimetallic carbides and nitrides are the active component.