Surface structure dependence by monofaceted CeO2 nanoparticles: Catalytic oxidation reactions

LI, MEIJUN; WU, ZILI; CALAZA, FLORENCIA C.; MULLINS, DAVID R.; XU, YE; OVERBURY, STEVEN H.

San Diego, CA

Conferencia; 243rd ACS National Meeting; 2012

AMERICAN CHEMICAL SOCIETY

Reducibility of pure and doped CeO2 is of interest in emission control catalysts because of the ability of the CeO2 to store and supply oxygen during oxidation catalysis. But, it is not known how the structure or crystallographic termination of the CeO2 affects the catalytic reaction rates and selectivity. Using CeO2 nanoparticles with controlled shapes including cubes, octahedra and rods that are terminated on (100), (111) and (110) surfaces respectively, we have investigated this structure dependence. Temperature programmed desorption, temperature programmed reaction, flow reactor rates, and in situ DRIFTS were used to probe adsorption states, desorption, reaction, oxidation rates and product selectivity for CO and ethanol oxidation. Results show pronounced differences between the three different morphologies. The results provide a basis for fundamental understanding of how surface coordination, bonding, decomposition and reaction are affected by the atomic structure of an oxide surface, especially important for reducible oxides.