Coating of structured catalytic reactors by plasma assisted polymerization of tetramethyldisiloxane

Abstract

An original process based on cold plasma assisted polymerization of tetramethyldisiloxane (TMDSO) in the presence of O 2 was developed to cover substrates showing various shapes (plate and foam). In the frame of catalytic application, this coating has to act as a bonding layer for the deposition of active phase such as VO x /TiO 2 well-known for its properties in NO x and volatile organic compounds abatement and in the production of chemical intermediates. Good results were obtained by the deposition of a 5-lm thick polysiloxane film followed by a thermal treatment under air at 6508C and by a remote nitrogen plasma post treatment. This procedure led to a silica-like layer allowing its coating in an aqueous suspension of TiO 2 . Such a multilayered material can be obtained homogeneously on the whole surface of a sample showing a 3D open geometry like metallic foam. Characterizations of the different steps of the elaborated multilayer material were performed by Fourier transformed infrared spectroscopy, Raman spectrometry, X-ray photoelectron spectroscopy, and electron probe micro-analyzer. POLYM. ENG. SCI., 51:940-947,

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

“…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 …”

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

“…To get an homogeneous layer of silicalike on plates the ppTMDSO layer was shown to necessarily be thinner than 9 lm, otherwise some parts of stainless steel could be uncovered as the result of shrinkage by ca. 70% [28,29]. The open structure of foams makes very difficult the use of methods of analysis usually suitable for powders and, for some of them, for functionalised plates.…”

“…specie on the surface of VO x /TiO 2 , which thereby accounted for lower activity and selectivity as compared to those shown by VO x /TiO 2 powders. To enhance the mechanical and chemical stabilities of the coated VO x / TiO 2 plates a silica-like primer was deposited by RPECVD directly on stainless steel [28,29]. Once the parameters of coating were optimized for plates, they were adapted with few modifications to coat stainless steel foams.…”

“…Finally, preliminary catalytic results in the oxidative dehydrogenation of propane utilising foams and powders were compared. The method of coating foams was directly inspired from the coating of stainless steel plates [28][29][30], and it required four main steps (Fig. 1).…”

Simulation of Chemical Vapor Infiltration and Deposition Based on 3D Images: A Local Scale Approach

“…An example of such an application was recently developed for use as a catalyst. A silica‐like coating onto stainless steel foams was obtained and used as an adhesion and diffusion barrier layer 6. While the deposition was shown to be effective inside the millimeter‐size channels, the mass distribution is not well understood.…”