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Carbon nanofibres composites with macroscopic shaping were successfully synthesised by chemical vapour decomposition (CVD) using a low loading in nickel as catalyst (≤1 wt.%). A high carbon nanofibres yield, i.e. 100 wt.% weight gain per hour of synthesis with respect to the initial catalyst weight was obtained, which significantly lowered the synthesis cost while the direct macroscopic shaping rendered more reliable the applications of these materials in conventional catalytic processes. [Copyright &y& Elsevier]

Abstract: The influence of the O2 pretreatment on the CO2 reforming of methane to synthesis gas has been investigated with Ni catalysts supported on β-SiC extrudate. The structure and properties of the catalysts were characterised by SEM, TEM and XRD techniques. The pretreatment of the catalyst by a mixture of CO2 and O2 significantly improves the catalytic activity for the CO2 reforming. On the Ni 5wt.% supported on β-SiC catalyst, the CH4 conversion has reached 90% with the O2 pretreatment instead of 80% by direct activation under CO2/CH4 mixture. The oxygen pretreatment seems to stabilize the metallic nickel phase instead of NiSi2. [Copyright &y& Elsevier]

Abstract: Over the last decades, sulfur recovery from the H2S-containing acid gases (issued from oil refineries or natural gas plants) has become more and more important due to the ever increasing standards of efficiency required by environmental protection pressures. The H2S-tail gas was directly oxidized by oxygen to yield elemental sulfur. A significant improvement of the H2S conversion and selectivity has been developed, however, the support which is the core of the process still needs to be improved. Recently, β-SiC has been reported to be an efficient and selective catalyst support for the H2S-to-S reaction. One expected reason for this superior yield should be due to the high thermal conductivity of the support. The high thermal conductivity of the silicon carbide plays an important role in the maintenance of the high selectivity by avoiding the formation of hot spots on the catalyst surface which could favor secondary reactions. On the other hand, insulator supports such as alumina exhibit a poor selectivity due to catalyst surface temperature runaway. [Copyright &y& Elsevier]

The properties of carbon nanotubes, used as a nanometric template and as a reactor for the synthesis of BETA zeolite, have been investigated. The confinement effect of the carbon nanotubes, induced by the high aspect ratio of the tubes could be effectively used for the synthesis of one-dimensional nanowire zeolitic materials under non-hydrothermal macroscopic conditions. Zeolite material is easily recovered by combustion of the nanotubes. The average sizes of the zeolite particles are about 20 nm. The BETA zeolite was successfully used as a catalyst for benzoylation of anisol. The zeolite catalyst exhibits a high activity compared to a commercial BETA, essentially due to its high external surface area. [Copyright &y& Elsevier]

Selective oxidation of H2S into elemental sulfur at near-ambient temperature have been carried out over NiS2 nanoparticles encapsulated inside multi-walled carbon nanotubes (MWNTs). The high capacity of solid sulfur storage on the MWNT-based catalyst compared to that of macroscopic SiC grains was thus attributed to the large void volume outside the MWNTs available for the sulfur storage when compared to the void volume outside the SiC grains. [Copyright &y& Elsevier]