Carbide-supported metal catalysts have been demonstrated to be highly active for a number of reactions including water gas shift and electrochemical hydrogen evolution. Their activity appears to be a consequence of intimate interactions between the metal and support. These interactions as well as the structures and compositions depend on the conditions used during preparation. The objective of research described in this paper was to define key aspects regarding the adsorption and reaction of metal precursor complexes with unpassivated, high surface area Mo 2C powders during wet impregnation. The rate of metal deposition and the final state of the metal were functions of the nature of the precursor (i.e., counter ion), electrostatic interactions, and red-ox reactions with the Mo 2C surface. The deposition rate decreased in the following order: H 2PtCl 6 ∼ Pd(NH 3) 4(NO 3) 2 ∼ CuCl 2 ∼ Cu(NO 3) 2 > Co(NO 3) 2 ∼ Ni(NO 3) 2 ≫ CoCl 2 ∼ NiCl 2 ∼ FeCl 2 ∼ Fe(NO 3) 3. The observed adsorption and red-ox behavior suggest that supporting metals onto native carbide surfaces could result in properties that are significantly different from those for metals supported on oxidized carbide surfaces.
- Metal deposition
- Molybdenum carbide
- Wet impregnation
ASJC Scopus subject areas
- Physical and Theoretical Chemistry