Erbium-doped YVO4 have been synthesized by means of a simple solution method having good photo activities under UV-like excitation for the water splitting half reactions. From the structural and morphological characterization it has been stated that the presence of Er3+ induces the promotion of luminescence. Moreover the incorporation of erbium clearly affects to the morphology YVO4 leading to…
Nanometric powdered TixTa1−xC0.5N0.5-based cermets were fabricated using a mechanically induced self-sustaining reaction and consolidated by spark plasma sintering. Highly dense cermets were obtained, and their chemistry, microstructure and mechanical properties were characterised by X-ray diffraction, scanning electron microscopy, image analysis, microindentation and nanoindentation. The microhardness was found to depend directly on the contiguity and size…
A set of powdered cermets based on (Ti,Ta,Nb)C xN 1-x carbonitride solid solutions were synthesized from mixtures of elemental powders by a mechanically induced self-sustaining reaction (MSR) method and subsequently sintered using a pressureless method. Differing nominal compositions of the hard phase were used, and the nature of the metallic-binder phase (Co, Ni, or Co-Ni)…
A kinetic study of the preferential oxidation of CO in H2 rich streams (CO-PrOx) over a cerium-copper oxide (CeCu) and a gold catalyst supported on cerium-iron oxide (Au/CeFe) is presented. The gold catalyst is very active but the CeCu oxide is more selective. A kinetic model describing the CO-PrOx system with CO2 and H2O in…
Different metallic supports (aluminum foams of 40ppi, honeycomb monolith and micromonolith of 350 and 1180cpsi, respectively) have been loaded with a 20%Co-0.5%Re/γ-Al2O3 catalyst by the washcoating method. Layers of different thicknesses have been deposited onto the metallic supports. The catalytic coatings were characterized measuring their textural properties, adhesion and morphology. These structured catalysts have been…
The different steps for manufacturing a microchannel reactor for the PROX reaction are discussed. Transient Liquid Phase bonding (TLP) using a Ni-B-Si amorphous melt spun is used for joining micromilled Al-alloyed ferritic stainless steel plates followed by recrystallization at 1200°C for 5h. A CuOx-CeO2 catalyst synthesized by the coprecipitation method was washcoated on the microchannel…
Monolithic CeO2 and Au/CeO2 catalysts were prepared using austenitic stainless steel (AISI 304) as metallic substrate. Both monolithic and powdered catalysts were characterized before and after CO oxidation reaction by N-2 adsorption desorption, XRD, SEM, TEM and GD-OES. Catalyst deposition on the stainless steel surface results in modifications of the catalyst, the oxide scale and…
A three-dimensional computational fluid dynamics (CFD) study of heat transfer in a microchannel reactor for the low-temperature Fischer-Tropsch synthesis (FTS) is presented. The microreactor studied is a steel block with 80 square microchannels of 1 mm of side arranged in cross-flow configuration for the transport of syngas and cooling water. Syngas space velocities in the…
A three-dimensional computational fluid dynamics (CFD) study of heat transfer in a microchannel reactor for the low-temperature Fischer-Tropsch synthesis (FTS) is presented. The microreactor studied is a steel block with 80 square microchannels of 1 mm of side arranged in cross-flow configuration for the transport of syngas and cooling water. Syngas space velocities in the…
The integration of the steam reforming and combustion of methane in a catalytic microchannel reactor has been simulated by computational fluid dynamics (CFD). Two models including 4 or 20 square microchannels of 20 mm of length and 0.7 mm of side have been developed. It has been assumed that a thin and homogeneous layer of…