Preparation of CuO/ZnO/Nb2O5 catalyst for the water-gas shift reaction

CuO/ZnO/Nb2O5 catalyst was prepared by combining the co-precipitation and deposition-precipitation preparation methods in order to develop a novel catalyst for water-gas shift reaction. The effect of alumina substitution for niobia and the influence of zinc oxide presence were evaluated by comparing the catalytic activity of CuO/ZnO/Nb2O5 catalyst with CuO/ZnO/Al2O3 and CuO/Nb2O5 catalytic activities. Nitrogen physisorption, X-ray diffraction, Energy dispersive X-ray spectroscopy, N2O titration and temperature-programmed reduction analysis were performed to evaluate the physicochemical properties of the materials and the catalytic tests were carried out under near-industrial conditions. CuO/Nb2O5 catalyst was inactive during all catalytic tests while CuO/ZnO/Nb2O5 catalyst exhibited significant higher TOF values compared with CuO/ZnO/Al2O3. Catalytic activity measurements revealed that zinc presence was important for catalytic activity under the studied conditions and indicated that the replacement of Al2O3 by Nb2O5 in the ternary catalyst as well as the presence of residual hydroxycarbonates promoted the catalytic activity.