RANEY TYPE COPPER-ZINC ALUMINUM CATALYST FOR WATER GAS SHIFT REACTION

The structure and the catalytic activity in the water-gas shift (WGS) reaction of a Raney type copper-zinc-aluminium catalyst has been studied. It has been established that after leaching of the alloy with alkali solution copper particles are formed, covered by a hydroxycarbonate film containing mainly a hydrotalcite like phase. Most probably this system is the precursor of the active sites, similar to the WGS catalysts obtained by coprecipitation. The Raney type catalysts manifested catalytic activity by an order of magnitude higher than that of the conventional coprecipitated catalysts. This could be explained by the formation of a complex catalytic system, containing a "polyelectrode" of a redox galvanic couple of copper ions, closed via the metal phase.