From Materials Science to Catalysis: Influence of the Coating of 2D- and 3D-Inserts on the Catalytic Behaviour of VOx/TiO2 in Oxidative Dehydrogenation of Propane

Abstract

The chemistry of the coating of stainless steel plates and foams with VO x /TiO 2 catalyst to be utilised in the oxidative dehydrogenation of propane is described. A primer layer of SiO 2 was first deposited by RPECVD, to anchor the active phase, to accommodate the difference of dilatation coefficient with steel and to act as a barrier against diffusion of poisonous steel elements. The coated VO x /TiO 2 foams were inserted in a tube that could also be loaded with VO x /TiO 2 powders to compare their catalytic performance. Preliminary results showed that the selectivity to propene was higher by 10% on silica-protected (ca. 5 lm thick) VO x /TiO 2 foam than in the absence of silica, and higher by more than 20% than VO x /TiO 2 powders at any conversion. The better performance was attributed to enhanced heat and mass transfers due to turbulent flow regime and to the high conduction of metallic foam. Hot spots which generate over-oxidation of propene were avoided. The choice of the substrate material, of which depend the mechanical and chemical properties of the active phase coating, and of the reactor configurations vs. the efficiency of heat and mass transfers was also commented.

Silicon Oxycarbide Films Produced by Remote Microwave Hydrogen Plasma CVD using a Tetramethyldisiloxane Precursor: Growth Kinetics, Structure, Surface Morphology, and Properties

“…c). The decrease in the intensity of the Si−CH 2 −Si band is associated with thermally induced crosslinking, which involves the conversion of the Si−CH 2 −Si linkages into carbosilane units with tertiary and quaternary carbon atoms, i.e., Si 3 CH and Si 4 C, respectively . The intensity of Si−O band decreases with rising T S .…”

“…Of a broad class of silicon‐based thin‐film materials amorphous hydrogenated silicon oxycarbide (a‐SiCO:H) films due to their many attractive properties, such as: high hardness and elastic modulus, low residual stress, low dielectric constant, and very low absorption coefficient, are of great interest. a‐SiCO:H films appear to be a promising coatings for a wide range of technological applications and they may be used, for example, as anode component in lithium ion batteries, dielectric material in ultra large‐scale integrated circuit chips, emitters of white or blue light, and coatings for catalytic reactors deposited on metallic support …”

Ultrathin BN nanosheets with zigzag edge: one-step chemical synthesis, applications in wastewater treatment and preparation of highly thermal-conductive BN–polymer composites

“…These 2D nanostructures possess some unique properties, including high specic surface area, large aspect ratio, sharp open edges, high thermal conductivity, high mechanical strength and carrier mobility, etc., which make them the ideal candidates for the preparation of gas sensors, catalysts, eld-emission devices, lithium-ion batteries and supercapacitors, etc. [1][2][3][4][5][6] For instance, Cu 2 O lms constructed from nanosheets possess superior performance to those constructed from Cu 2 O nanoparticles when used in photovoltaic cells. 7 A vertically aligned BiOCl nanosheet array shows much higher photocatalytic performance.…”

Biomass-derived Platform Molecules Upgrading through Catalytic Processes: Yielding Chemicals and Fuels

“…This however opens a lot of opportunities for progress in catalytic processes for which two approaches can be undertaken, namely (i) acting on the catalytic active phases, and (ii) acting on the operating conditions and particularly on the way the reactant and the catalyst are contacted. Indeed, structured reactors 5) 7) , membrane reactors 8), 9) or nonsteady state operating reactors can bring significant improvements for such reactions.…”