Shape/Crystal Facet of Ceria Induced Well-Dispersed and Stable Au Nanoparticles for the Selective Hydrogenation of Phenylacetylene

Abstract A series of CeO 2 with the morphology of nanocube (NC), nanopolyhedron (NP) and nanorod (NR) were synthesized by hydrothermal method as substrates to support monometallic Au catalysts. Insight into support morphology-dependent the property of active component and catalytic behavior for the selective hydrogenation of phenylacetylene has been performed. Specifically, nanocube ceria could disperse monometallic Au nanoparticles due to a large amount of low coordinated sites that readily generated the strong interaction for anchoring active metal, whereas the polyhedron and rod-like ceria supported Au nanoparticles possessed large size and wide particle distribution. As expected, well-dispersed and stable Au/CeO 2 nanocube demonstrated 83% of selectivity towards styrene when the conversion of phenylacetylene reached 90%, which was much higher than that of others. Preferable activity was mainly ascribed to small size of Au nanoparticles, which facilitated the adsorption/dissociation of hydrogen considered as the rate-determining step. Enhanced selectivity was due to the electronic effect that caused by strong interaction between Au and cubic CeO 2 , which also contributed to good stability. This work not only provides a facile method for the preparation of highly dispersed and efficient Au/CeO 2 catalysts by modulating the morphology of support, but also offers a novel idea for the fabrication of other highly dispersed supported metal catalysts with enhanced behavior in heterogeneous catalysis. Graphical Abstract