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Promoted (CoMo/Al2O3 and NiMo/Al2O3) and unpromoted (Mo/Al2O3) catalysts were tested in the hydrodeoxygenation of 2-ethylphenol as a model compound of bio-crude under various partial pressures of H2S and CO. The catalytic tests were carried out at 340 °C under 7 MPa of total pressure in a fixed-bed microreactor. H2S, needed to maintain the sulfidation level of the catalysts, showed promoting or inhibiting effects depending on the catalyst tested and the deoxygenation pathway considered. Over the three catalysts, H2S was found to slightly promote the HYD pathway, which first involves the hydrogenation of the aromatic ring, whereas it strongly inhibited the DDO pathway, which consists of a direct C–O bond scission, particularly on the CoMo/Al2O3 catalyst. In addition, a strong though reversible inhibition by CO was found over CoMo/Al2O3 for both deoxygenation pathways, while a limited effect was observed over NiMo/Al2O3. Differences in inhibition induced by H2S and CO observed over both promoted catalysts suggested that different active sites are involved in the hydrodeoxygenation of 2-ethylphenol, depending on the nature and the localisation of promoters and on the transformation pathway. [ABSTRACT FROM AUTHOR]

Pure ceria-zirconia mixed oxides Ce xZr1− xO2 with high specific surface area were synthesized with a new epoxyde driven sol–gel route and characterized by thermal analysis, X-ray diffraction studies and transmission electron microscopy. This sol–gel method is cheap and uses only a few steps. The Ce xZr1− xO2 mixed oxides were obtained in the range of 0 ≤ x ≤ 1 (except for x = 0.8) and crystallised at 350 °C after decomposition of the gels. This temperature is very low in comparison with the other methods. The studies of the influence of different synthesis parameters (concentration of the sol and decomposition temperature) allowed us to determine the conditions to obtain the best homogeneity in the gel to avoid the formation of a mixture of phases instead of mixed oxides. This approach leads to the synthesis of oxide with specific surface area above 100 m2 g−1. The elaboration of an ambigel could increase this value up to 195 m2 g−1 for x = 0.5. This sol–gel synthesis offers new perspectives for these oxides in several applications. Generally, these oxides are difficult to obtain pure in large range of composition at low-temperature and with high specific surface area by other methods. [ABSTRACT FROM AUTHOR]

Abstract: MoS2 was dispersed into the porosity of MCM-41 and SBA-15 ordered mesoporous materials by means of thermal spreading of MoO3 oxide, followed by sulfidation. Catalysts with various Mo loadings were prepared (namely 9, 14 and 20wt%), thoroughly characterized using XRD N2-sorption, and TEM, and their activity in hydrodesulfurization of dibenzothiophene was investigated. Depending on the pore size of the support, a nanocasting of the sulfide particles was observed, and its effect on HDS activity was discussed. [Copyright &y& Elsevier]

High-specific-surface-area MgF 2 was prepared by microwave-assisted solvothermal synthesis. The influences of the solvent and the magnesium precursors, and the calcination atmospheres, on the nanoparticle sizes and specific surface areas, estimated by X-Ray Powder Diffraction, N 2 sorption and TEM analyses, were investigated. Nanocrystallized (~7 nm) magnesium partially hydroxylated fluorides (MgF 2-x (OH) x ) with significant specific surface areas between 290 and 330 m 2 ∙g -1 were obtained. After activation under gaseous HF, MgF 2-x (OH) x catalysts underwent a large decrease of both their surface area and their hydroxide, rates as shown by their 19 F and 1 H solid-state NMR spectra. Expect for MgF 2 prepared from the acetate precursor, an activity of 30-32 mmol/h∙g was obtained which was about 40% higher compared with that of MgF 2 prepared using Trifluoroacetate method (21.6 mmol/h∙g).