MoS2 catalysts were prepared on Al2O3, SiO2 and TiO2 support. On the oxidic forms, Raman and UV-visible characterizations show the strong Mo-TiO2 interaction and the weak Mo-SiO2 one that leads to a poorer Mo dispersion s. MoS2 nanoparticles were then studied by TEM and adsorption of CO followed by infra-red spectroscopy which allows the distinction and quantification of the two stable edges namely the S-and M-edges. It appears that the slab morphology is strongly modified by the support nature: thus the stronger the MoS2-support interaction the higher the S-/M-edge ratio. Finally, MoS2 morphology impacts the catalytic activity in thiophene HDS: (1) an increase of the S-/M-edge ratio leads to the increase of the TOF value for Mo sulfided supported on Al2O3 and SiO2; (2) a specific behavior with high TOF value of mainly M-edge sites and strong hydrogenating properties is underlined for Mo/TiO2.

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6H and 4H–SiC epilayers were Al-implanted at room temperature with multiple energies (ranging from 25 to 300 keV) in order to form p-type layers with an Al plateau concentration of 4.5×1019 cm-3 and 9×1019 cm-3. Post-implantation annealing were performed at 1700 or 1800 °C up to 30 min in Ar ambient. During this process, some samples were encapsulated with a graphite (C) cap obtained by thermal conversion of a spin-coated AZ5214E photoresist. From Atomic Force Microscope measurements, the roughness is found to increase drastically with annealing temperature for unprotected samples while the C capped samples show a preservation of their surface states even for the highest annealing temperature. After 1800°C/30 min annealing, the RMS roughness is 0.46 nm for the lower fluence implanted samples, slightly higher than for unimplanted samples (0.31 nm). Secondary Ion Mass Spectroscopy measurements confirm that the C cap was totally removed from the SiC surface. The total Al-implanted fluence is preserved during postimplantation annealing. A redistribution of the Al dopants is observed at the surface which might be attributed to Si vacancy-enhanced diffusion. An accumulation peak is also observed after annealing at 0.29 9m, depth corresponding to the amorphous/crystalline interface that was determined on the as-implanted samples by Rutherford Backscattering Spectroscopy in channeling mode. The redistribution of the dopants has an impact on their electrical activation. A lower sheet resistance (Rsh= 8 k) is obtained for samples annealed without capping than for samples annealed with C capping (Rsh= 15 k ).

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