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Self-decontaminating photocatalytic textiles functionalized by the layer-by-layer approach with high aspect ratio WO3-modified titanate nanotubes have been developed and successfully used under solar light illumination for the photocatalytic degradation of organophosphorous and organosulfide chemical weapon agents. This multilayer building method, unlike both dipping and spray techniques, has been efficiently applied to textile substrates using polyethyleneimine as counter polyelectrolyte for homogeneously functionalizing textiles by a thin layer of a dense network of entangled WO3-modified titanate nanotubes, and preparing self-decontaminating photocatalytic textiles highly efficient toward the removal under solar light of the yperite blister live agent and of dimethylmethylphosphonate as neurotoxic agent simulant. Solar light responsive high surface WO3-modified titanate nanotubes were synthesized by hydro-thermally treating TiO2 powder, with tungstate salt impregnation prior to the final calcination step.

3D solid carbon foams were used as support for preparing photocatalytic materials working in a traversing-flow mode and designing efficient vapor phase flow-through structured photoreactors. The carbon foams were obtained by resin polymerization and pyrolysis treatments starting from a three-dimension structured reticulated polyurethane foam used as a pre-shaped precursor. The 3D solid carbon foam supported TiO2 photocatalysts were characterized in terms of morphology, pressure drop, light transmission ability and static mixer role, and using the vapor phase methanol UV-A photocatalytic oxidation as target reaction. The foam-structured photoreactor benefits from a strong gain of exposed surface leading to an increased surface to reactor volume ratio with a large increase in the TiO2 amount inside the reactor. Further, the improved air-to-surface contact probability ratio induced by the static mixer effect of the foam resulted in a high methanol conversion obtained at a given TiO2 amount in the reactor. The potential of this 3D-structured photocatalytic material for flow-through photoreactors targeting real applications was also highlighted by induced ultra-low-pressure drops resulting from a high porosity and a large cell size morphology.

A tool for direct and quantitative determination of surface Bronsted acidity of solids in terms of number, type and force based on quantitative H/D exchange kinetic between gaseous D 2 O and the acid solid, i.e. the hydron of the –O–H acid surface groups, has been developed. This method has been applied to materials covering the whole range of acidity, from very low acidic materials (e.g. carbonaceous solids) to high acidic materials ( e.g. acidic oxides or zeolites). Calibration was performed using well-characterized zeolites with known acidities and allowed the number of surface Bronsted acid sites (in μmol/g) to be determined using the integrated surfaces of the H/D experimental exchange curve given by the direct measurement of the exchanged HDO molecule signal by mass spectrometry. The determination of the force of the acidity was directly linked to the rate constant of the first step of the H/D exchange. This method allows, after deconvolution of the H/D experimental curve, the number and force of each type of surface Bronsted acid sites to be determined.

High activity for the direct oxidation of H2S into elemental sulfur at low reaction temperature (40–60 °C) on medium surface area silicon carbide-supported nickel sulfide (NiS2/SiC) catalyst was attributed to the formation of a highly active superficial nickel oxysulfide. The hypothesis of the superficial formation of either nickel oxide or nickel sulfate was rejected. The superiority of the SiC support in terms of performance as compared to silica, high surface area alumina and activated charcoal was evidenced. The high stability of the SiC-supported catalyst as a function of time and solid sulfur loading in the presence of water was explained by a peculiar mode of sulfur deposition, involving the role of water and the hydrophilic/hydrophobic duality of the SiC support surface. Water acts as a conveyor belt, continuously cleaning the active phase particles, located on the hydrophilic oxygen-containing surfaces of the support. Hydrophobic pure SiC, located outside the mesoporosity and exempt of active phase, remains as an available surface for the storage of high amounts of solid sulfur.

Iron supported on silicon carbide (SiC) is shown to be a high conversion catalyst for the oxidation of H2S with a high selectivity into elemental sulfur above sulfur dewpoint in the presence of large amounts of oxygen and steam in the feed. The active phase is probably an iron oxysulfide or a non-stoichiometric sulfate phase. It is stable for several weeks in an industrial micropilot plant, and no deactivation is observed even in the presence of a large amount of steam. These performances are due to the intrinsic physical properties of the SiC carrier but also because of the optimal dispersion of the active phase.

Silicon carbide microtubes with medium surface area, 30–70 m2 g−1, were successfully prepared by shape memory synthesis involving the reaction between SiO vapors and low surface area, 1–2 m2 g−1, carbon microfibers. The gross morphology of the carbon microfibers was conserved during the carburization process. After calcination at 600°C in order to eliminate the unreacted carbon, hollow SiC microtubes were obtained. The pore size distribution of the material was centered around 10 nm, allowing a high accessibility of potential reactants to an active phase during catalytic reactions. The surface was covered by an amorphous layer 3 nm thick. XPS measurements revealed that this amorphous phase was composed of a mixture of SiO2 and SiOxCy. Soda treatment at 80°C allowed complete removal of this surface phase without any change in the material morphology. A similar result was also obtained after treatment with an aqua regia medium.