The chemoselective continuous gas phase (T = 573 K; P = 1 atm) hydrogenation of nitroarenes (p-chloronitrobenzene (p-CNB) and m-dinitrobenzene (m-DNB)) has been investigated over a series of oxide (Al2O3 and TiO2) supported Au and Ni-Au (1 : 10 mol ratio; 0.1-1 mol% Au) catalysts. Monometallic supported Au with mean particle size 3-9 nm promoted exclusive formation of p-chloroaniline (p-CAN) an...

Density functional theory is used to determine the reaction mechanisms of CO oxidation and the active oxygen species on a Au/TiO2 model catalyst. The model consists of a Au rod supported along the TiO2 [11̅0] direction of the TiO2(110) surface. An interfacial Au/Ti5c site at the interface boundary is identified to be particularly active toward O2 adsorption and dissociation. At this site, O2 dis...

A gold nanoparticle-coated and surface-textured TiO2 inverse opal (Au/st-TIO) structure that provides a dramatic improvement of photoelectrochemical hydrogen generation has been fabricated by nano-patterning of TiO2 precursors on TiO2 inverse opal (TIO) and subsequent deposition of gold NPs. The surface-textured TiO2 inverse opal (st-TIO) maximizes the photon trapping effects triggered by the l...

The interaction of carbon monoxide and oxygen with gold particles supported on zinc oxide, alumina, and titania was investigated by microcalorimetry. Multiple processes were detected during CO adsorption, including adsorption of CO on the gold particles and support, oxidation of CO, and formation of carbonates. The rate of O2 adsorption was much slower than that of CO adsorption. The heats and ...

The structure and electronic properties of 1-ML Au supported on TiO2~110! have been theoretically investigated using the full potential linearized augmented plane-wave method. Based on total-energy and atomicforce calculations, the preferential adsorption site for the Au adatom is predicted to be the atop site above the fivefold surface Ti atom, with a bond length of dAu-Ti52.66 Å and an adsorp...

Model catalysts consisting of Au and Ag clusters of varying size have been prepared on single crystal TiO2(110) and ultra-thin films of TiO2, SiO2 and Al2O3. The morphology, electronic structure, and catalytic properties of these Au and Ag clusters have been investigated using low-energy ion scattering spectroscopy (LEIS), temperature-programmed desorption (TPD), X-ray photoelectron spectroscop...

A facile method was used to prepare uniform Au NR/TiO2 and Au/Ag NR/TiO2 core-shell composite nanoparticles. Au/Ag NR/TiO2 nanoparticles were found to display significantly enhanced visible light photo-catalytic activity compared to Au NR/TiO2 and the commercially available TiO2 nanoparticles. The enhancement mechanism was ascribed to injection of hot electrons of photo-excited Au/Ag NRs to TiO...

The catalytic hydrogenation of lactic acid to 1,2-propanediol with supported Ru catalysts in water was investigated. The influence of catalyst support (activated carbon, γ-Al2O3, SiO2, TiO2, and CeO2) and promoters (Pd, Au, Mo, Re, Sn) on the catalytic performance was evaluated. Catalytic tests revealed that TiO2 yields the best Ru catalysts. With a monometallic Ru/TiO2 catalyst, a 1,2-propaned...

Investigation of atomically precise Au nanoclusters provides a route to understand the roles of coordination, size, and ligand effects on Au catalysis. Herein, we explored the catalytic behavior of a newly synthesized Au22(L8)6 nanocluster (L = 1,8-bis(diphenylphosphino) octane) with in situ uncoordinated Au sites supported on TiO2, CeO2, and Al2O3. Stability of the supported Au22 nanoclusters ...

Supported gold nanoparticles are highly selective catalysts for a range of both liquid-phase and gas-phase hydrogenation reactions. However, little is known about their stability during gas-phase catalysis and the influence of the support thereon. We report on the activity, selectivity, and stability of 2-4 nm Au nanoparticulate catalysts, supported on either TiO2 or SiO2, for the hydrogenation...