Raney copper catalysts for the water-gas shift reaction: I. Preparation, activity and stability

Characterisation of partially leached Raney copper catalysts demonstrated that the chemical nature of the reactant surface could be determined by controlling the leaching process. Initial water-gas shift (WGS) activity of the Raney copper catalysts at the stated conditions compared favourably to the co-precipitated and industrial catalyst alternatives due to a similar active phase composition and high metallic copper surface areas. Raney copper catalyst deactivation in a poison-free environment was attributed to copper crystallite sintering, primarily as a result of a zinc oxide deficiency. Long term (850 h) stability of the Raney catalyst is reported for the first time. Stability improved significantly with increased ZnO loading as a result of better contact between the copper surface and ZnO crystallites. The stabilizing effect of incorporated zinc was independent of its original source. The role of aluminium was to produce Raney copper of high surface area. No beneficial effects of residual alumina in the active catalysts were observed. (C) 1997 Elsevier Science B.V.