Au/CeO2 metallic monolith catalysts: influence of the metallic substrate

Ceria-based gold catalysts were successfully deposited on ferritic stainless steel (Fecralloy) and aluminium monoliths. The prepared monolithic and reference powder catalysts were characterized by means of S-BET, X-ray diffraction, glow discharge optical emission spectroscopy and scanning electron microscopy-energy dispersive X-ray analysis techniques and tested in the CO oxidation reaction. Characterization results put in evidence the…

Preferential oxidation of CO over Au/CuOx–CeO2 catalyst in microstructured reactors studied through CFD simulations

A computational fluid dynamics (CFD) simulation study of the preferential oxidation of CO (CO-PROX) in microstructured reactors consisting in square and semicircular microchannels coated with an Au/CuOx–CeO2 catalyst is presented. The CO content of the feed stream was set at 1 vol.%. A parametric sensitivity analysis has been performed under isothermal conditions revealing that an…

Gold(III) stabilized over ionic liquids grafted on MCM-41 for highly efficient three-component coupling reactions

Two alkoxysilyl-modified ionic liquids (ILs) have been synthesized and further grafted onto mesoporous silica, MCM-41; these ionic liquids were used for dispersing AuCl3 catalysts that activate C–H bonds as required for the synthesis of propargylamines by coupling alkyne, aldehyde and amine (A3 coupling) species. 29Si NMR experiments demonstrate the formation of covalent bonds between alkoxysilyl-modified…

Effect of the alloy on micro-structured reactors for methanol steam reforming

Micro-monoliths and foams made of aluminium, Fecralloy® and brass were studied as substrates for structured systems for methanol steam reforming (MSR). All the alloys exhibited very adherent oxide layer produced by pre-treatment to improve the adhesion between substrate and catalyst. 2.5% Pd/ZnO catalyst was prepared and deposited on structured substrates. Both, good catalyst adhesion and…

Steam reforming of methanol over supported Ni and Ni–Sn nanoparticles

The influence of the synthesis method and Sn addition on Ni/CeO2–MgO–Al2O3 catalyst is correlated to its catalytic behavior in the reaction of methanol steam reforming. The catalysts prepared by impregnation method are compared to samples obtained by deposition of previously obtained nanoparticles by the polyol method. X-ray diffraction (XRD), specific surface area measurements and H2-temperature…

In situ characterization of iron-promoted ceria–alumina gold catalysts during the water-gas shift reaction

In this work an in situ XRD and XANES study of two gold catalysts supported on iron-promoted ceria–alumina carriers was carried out during the water-gas shift reaction (WGS). The first catalyst, Au/CeO2–FeOx/Al2O3, was prepared using a commercial alumina support in order to obtain a Ce–Fe oxide solid solution and in the second one, Au/FeOx/CeO2–Al2O3, an…

Influence of the O2/CO ratio and the presence of H2O and CO2 in the feed-stream during the preferential oxidation of CO (PROX) over a CuOx/CeO2-coated microchannel reactor

The catalytic performance of a CuOx/CeO2 powder catalyst and that of a microchannel reactor or microreactor (MR) coated with the same solid was determined and compared. The catalytic activity measurements were carried out with varying O2/CO molar ratios in the feed-stream. In addition, the influence of the presence of CO2 and H2O in the reaction…