Study of the temperature-programmed reaction synthesis of early transitionmetal carbide and nitride catalyst materials from oxide precursors

The synthesis of high surface area carbide and nitride materials from binar y and ternary oxides of vanadium, niobium, tantalum, molybdenum, and tungst en, suitable for use as catalysts for a wide range of reactions, has been i nvestigated via the temperature-programmed reaction (TPRe) method, in vario us gas mixtures. TPRe of oxides in CH4/H-2, C2H6/H-2, or NH3 yield material s with surface areas >40 m(2) g(-1). For the reaction with ethane or ammoni a the reaction appears to proceed topotactically while that with methane do es not; however, the conversion of nitrides to-carbides in CH4/H-2 does app ear to proceed topotactically.