An unexpected oxygen-assisted reduction of cationic Au species by CO was found on a Au/SiO(2) catalyst at room temperature and the produced metallic Au species plays an essential role in CO oxidation on Au/SiO(2).

The formation of Pd carbide (PdCx) during the synthesis of vinyl acetate (VA) was investigated over Pd/SiO2 catalysts with two different Pd particle sizes, as well as over a Pd–Au/SiO2 mixed-metal catalyst. XRD data show that PdCx was produced in the pure Pd catalysts after reaction based on the downshift of the Pd(111) and (200) XRD features. The smaller Pd particles showed greater resistance ...

We carried out the carbon nanotubes (CNTs) growth from an Au catalyst with two different kinds of chemical vapor deposition (CVD) methods. In case of thermal CVD (TCVD), high quality single-walled carbon nanotubes (SWNTs) can be grown. On the other hand, only poorly crystallized CNTs are synthesized with plasma CVD (PCVD). Through the parametric investigations, it is found that the hydrogen gas...

The effect of gold oxidation state and carbon structure on the activity of Au/C catalyst for the hydrochlorination of acetylene was investigated by a combined approach using TPR, XPS and porosimetry determinations. The activity of the catalyst in the synthesis of vinyl chloride monomer was found to be dependent from the presence of Au 3+ species into the catalyst. However, by preparing catalyst...

Carbon-supported Pt–Au (Pt–Au/C) catalyst is prepared separately by impregnation, colloidal and micro-emulsion methods, and characterized by physical and electrochemical methods. Highest catalytic activity towards oxygen-reduction reaction (ORR) is exhibited by Pt–Au/C catalyst prepared by colloidal method. The optimum atomic ratio of Pt to Au in Pt–Au/C catalyst prepared by colloidal method is...

We investigate the correlation between the Ga concentration of the catalyst droplet and the adopted crystal structure of individual GaAs nanowires grown by molecular-beam epitaxy using Au as a catalyst material. Through a postgrowth analysis the Ga content of the catalyst droplet during growth is estimated and related to the observed crystal structure of the nanowires. Depending on the Ga conce...

Non-thermal plasma activation has been used to enable low-temperature water-gas shift over a Au/CeZrO4 catalyst. The activity obtained was comparable with that attained by heating the catalyst to 180 °C providing an opportunity for the hydrogen production to be obtained under conditions where the thermodynamic limitations are minimal. Using in situ diffuse reflectance infrared Fourier transform...

A novel HAuCl4@UiO-66-NH2 material has been obtained and utilized as a heterogeneous Au(III) catalyst. This Au(III) catalyst was able to promote the formation of a variety of dihydrochalcones starting from 2H-chromenes in moderate to good yields. A tandem hydride shift/hydration reaction sequence has been proposed based on deuterium labeling studies, which revealed a 1,5-hydride shift reaction ...

Gold nanoparticles supported on halloysite nanotubes (Au/HNTs) were prepared by a homogeneous deposition-precipitation method. The specific characteristics of the catalyst were characterized in detail, in relation to their performance for solvent-free oxidation of benzyl alcohol. The particular structure of the catalyst resulted in high catalytic activity and stability compared with other suppo...

Knowledge of the catalyst concentration within vapor-liquid-solid (VLS) grown semiconductor wires is needed in order to assess potential limits to electrical and optical device performance imposed by the VLS growth mechanism. We report herein the use of secondary ion mass spectrometry to characterize the Au catalyst concentration within individual, VLS-grown, Si wires. For Si wires grown by che...