Support Effects on Nickel Hydroxide and Oxide Nanorods Supported Au Nanoparticles for CO Oxidation

The support effect of supported nanogold in catalytic transformations is of vital importance in the heterogeneous catalysis process. In this work, NiO-nanorod and Ni(OH)(2)-nanorod are prepared and adapted to accommodate Au colloids ( size: 2.0 nm), forming the Au-NiO and Au-Ni(OH) (2) interfaces. Upon calcination at 300 degrees C in air, TEM images show that the Au particles on Ni(OH)(2)-nanorod enlarge to 2.0-6.5 nm and these on NiO is 2.0-4.5 nm, suggesting the stronger metal-support interaction of Au particles and NiO oxide. Au/NiO catalysts outperform the homologous Au/Ni(OH) (2) in the catalytic CO oxidation (including higher activity and durability), which is mainly attributed to its higher concentration of surface chemisorbed oxygen and Au-0 species and less basic sites. Furthermore, DRIFTS results demonstrate that CO is activated over the gold particles at low reaction temperature and CO molecules also can react with bare NiO supports at high reaction temperature (e.g. > 300 degrees C).