Selective Hydrogenation of Acetylene Over Gold Nanoparticles Supported on CeO2 Pretreated Under Different Atmospheres

Supported gold catalysts are highly efficient for selective hydrogenation of acetylene. It has been shown that reducible materials such as ceria may influence the catalytic performance due to its unique charge shift between reduced and oxidized state. However, its role in catalytic performance remains fiercely debated. In this paper, differently morphological CeO2 supported Au catalysts were prepared with pretreatment under air and H2 atmospheres respectively, and evaluated for selective hydrogenation of acetylene. No matter with rod (abbreviated as R) or polyhedral (abbreviated as P) shape, the catalysts of Au/CeO2 reduced in air exhibits better catalytic performance than that in H2 atmosphere. The Au/CeO2 (R)-air catalyst shows the best performance. The C2H2 conversion is about three times of that over the catalyst of Au/CeO2 (R)-H2 at 300 °C. The Raman result and XPS analysis clearly showed a dependence of catalytic activity on the oxygen vacancy concentration of catalysts, revealing the correlation between its defect features and pretreatment atmosphere. Our report not only deepens the knowledge of catalytic performance affected by defect features of catalyst but also provides a possibility for the efficient heterogeneous gold/ceria catalysts by controlling the pretreatment atmosphere.