Effect of the ZrO2 phase on the structure and behavior of supported Cu catalysts for ethanol conversion

• Cu catalysts supported on am-, m-, and t-ZrO2 for selective ethanol conversion.
• Cu/m-ZrO2 catalyst shows a high selectivity to ethyl acetate.
• The high rate of ethyl acetate is defined by oxygen mobility from bulk ZrO2 to Cu.
• A high rate for acetaldehyde formation is observed for Cu/t-ZrO2 catalyst.

The effect of amorphous (am-), monoclinic (m-), and tetragonal (t-) ZrO2 phase on the physicochemical and catalytic properties of supported Cu catalysts for ethanol conversion was studied. The electronic parameters of Cu/ZrO2 were determined by in situ XAS, and the surface properties of Cu/ZrO2 were defined by XPS and DRIFTS of CO-adsorbed. The results demonstrated that the kind of ZrO2 phase plays a key role in the determination of structure and catalytic properties of Cu/ZrO2 catalysts predetermined by the interface at Cu/ZrO2. The electron transfer between support and Cu surface, caused by the oxygen vacancies at m-ZrO2 and am-ZrO2, is responsible for the active sites for acetaldehyde and ethyl acetate formation. The highest selectivity to ethyl acetate for Cu/m-ZrO2 catalyst up to 513 K was caused by the optimal ratio of Cu0/Cu+ species and the high density of basic sites (O2−) associated with the oxygen mobility from the bulk m-ZrO2.

Effect of ZrO2 phases on the formation of acetaldehyde and ethyl acetate from ethanol over Cu/ZrO2 catalysts.Figure optionsDownload high-quality image (98 K)Download as PowerPoint slide