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摘要
The Cu/Al2O3/ZnO(0001)-Zn ternary model catalysts and their binary analogues were prepared and characterized. It was found that Al2O3 grew on the ZnO(0001)-Zn surface by a layer-by-layer model, whereas Cu grew on the ZnO(0001)-Zn surface as two-dimensional clusters up to 0.2 monolayers (ML), and thereafter formed three-dimensional clusters. Because of the layer-by-layer growth of Al2O3 on the ZnO(0001)-Zn, Cu/Al2O3 can be considered without the effect of ZnO. Ternary model catalyst Cu/Al2O3/ZnO(0001)-Zn, which has all three parts on the surface, was prepared by deposition of Cu on the surface of Al2O3/ZnO(0001)-Zn. Low-energy ion scattering spectra showed that Cu preferred to locate at the Al2O3/ZnO interfaces. Compared with Cu/ZnO, the addition of Al2O3 obviously suppressed the reduction of copper oxides and led to a higher concentration of Cu+. The Cu clusters were found to be covered by thin ZnOx overlayers after reduction of Cu/Al2O3/ZnO(0001)-Zn by using H-2. Therefore, the high activity of industrial Cu/ZnO/V catalysts may origin from Cu+-rich clusters at the Al2O3/ZnO interface that are covered by thin ZnOx overlayers.
- 出版日期2017-8-4
- 单位厦门大学
