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...

Since their introduction by Haruta, oxide supported Au catalysts with Au nanoparticles (NPs) of few nanometers in diameter have attracted enormous interest because of their high activity for various oxidation and reduction reactions most prominently the CO oxidation reaction. Mechanistic details and hence the physical origin of their high activity, however, are still controversial. Focusing on ...

Tetrahexahedral Pt nanocrystals (THH Pt NCs), bound by high index facets, belong to an emerging class of nanomaterials that promise to bridge the gap between model and practical electrocatalysts. The atomically stepped surfaces of THH Pt NCs are extremely active for the electrooxidation of small organic molecules but they also readily accommodate the dissociative chemisorption of such species, ...

Multi-walled carbon nanotubes were synthesized on a Ni/Au/Ti substrate using a thermal chemical vapor deposition process. A Ni layer was used as a catalyst, and an Au layer was applied as a barrier in order to prevent diffusion between Ni and Ti within the substrate during the growth of carbon nanotubes. The results showed that vertically aligned multi-walled carbon nanotubes could be uniformly...

Au/CeLaOx mixed oxide catalysts containing 0.5 to 1.0 wt% Au were prepared via coprecipitation with HAuCl4, the appropriate nitrate precursors, and either urea or Na2CO3 as the precipitant. BET surface area measurements for the Au/CeLaOx catalysts varied in the range of 16-107 m/g depending on the precipitant, aging time, and calcination conditions. The catalysts were tested for the selective o...

We provide direct evidence of a water-mediated reaction mechanism for room-temperature CO oxidation over Au/TiO2 catalysts. A hydrogen/deuterium kinetic isotope effect of nearly 2 implicates O-H(D) bond breaking in the rate-determining step. Kinetics and in situ infrared spectroscopy experiments showed that the coverage of weakly adsorbed water on TiO2 largely determines catalyst activity by ch...

A simple, microwave-assisted route for producing Au/Ag concentred sols by glucose reduction in water was developed. Ag-Au bimetallic nanoparticles stabilized by polyvinylpyrrolidone (PVP) were characterized and their catalytic activity was studied in the reduction of 4nitrophenol (4-NP) with NaBH4. Moreover they were tested as red ceramic inks for ink-jet printing technology. Since the research...

Homogeneous immobilization of gold nanoparticles (Au NPs) on mesoporous silica has been achieved by using a one-pot synthesis method in the presence of organosilane mercapto-propyl-trimethoxysilane (MPTMS). The resultant Au NPs exhibited an excellent catalytic activity in the solvent-free selective oxidation of cyclohexane using molecular oxygen. By establishing the structure-performance relati...

Room-temperature extracellular biosynthesis of gold nanoparticles (Au NPs) was achieved using Escherichia coli K12 cells without the addition of growth media, pH adjustments or inclusion of electron donors/stabilizing agents. The resulting nanoparticles were analysed by ultraviolet-visible (UV-vis) spectrophotometry, atomic force microscopy, transmission electron microscopy and X-ray diffractio...

Heterogeneous catalysis, which is widely used in the chemical industry, makes a great use of supported late-transition-metal nanoparticles, and bimetallic catalysts often show superior catalytic performances as compared to their single metal counterparts. In order to optimize catalyst efficiency and discover new active combinations, an atomic-level understanding and control of the catalyst stru...