Study of ZnO Supported Ni-Cu Bimetallic Catalysts

A series of Ni-Cu/ZnO catalysts were prepared by co-precipitation, characteed by ternp erature-programmed reduction （TPR）, magnetic susceptibility, X-ray photoelectron spectroscopy （XPS）techniques and studied in CO hydrogenation. TPR results revealed that the support, ZnO, disperses CuO, but strongly interactes with NiO. After reduction, Ni-Cu alloy was formed. Magnetic susceptibility and XPS results further indicated that Cu enriches on the alloy and there might be an electronic effect between Ni and Cu, i.e. Cu Aught donate electrons to Ni. In CO hydrogenation, all the catalysts seldrively catalyzed the formation of methanol.With the increase of Ni/Cu ratios, the selectivity to methanol decreases, while that to methane increases. None of the bimetallic catalysts showed the activity of a sample of combination of Ni/ZnO and Cu/ZnO with corresponding composition. The total reaction rates did not increase appredably with increasing Cu concentration at constant Ni content, but decreased drasticallyWhen Ni was added at constant Cu content. The results of this study shows that there are both interactions between Ni and Cu metals and interactions between metals and support. The interaction between metals can weaken the interactions between metals and support.