S. Brunet

Effect of H2S and CO on the transformation of 2-ethylphenol as a model compound of bio-crude over sulfided Mo-based catalysts: propositions of promoted active sites for deoxygenation pathways based on an experimental study

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.

Influence of the morphology and of the composition of chromium oxides on their catalytic activity for the gas phase fluorination of 1,1,1-trifluoro-2-chloro-ethane. Preparation of hydrofluorocarbons

Abstract The morphology and the oxygen content of chromium oxides used in the fluorination of CF 3 CH 2 Cl are important parameters for their catalytic activity. The oxides constituted by polyhedral particles and particles in platelet shape have a catalytic activity per surface unit greater than the chromium oxides constituted by spheric and by needle particles. An excess of oxygen compared to CrO 1.5 is necessary to obtain the highest intrinsic catalytic activity but the amount of the excess seems not to be important. Chromium oxides (CrO 1.7 and CrO 1.9 ) which have not the same oxygen excess have the same intrinsic catalytic activity.

Characterization of hydrodenitrogenation catalysts by O2 chemisorption

O2 chemisorption on sulfided NiMo/Al2O3 catalysts with Ni/Ni+Mo = 0 to 1 was measured at 273 K. The quantities of chemisorbed O2 were compared to the activities of the catalysts in biphenyl hydrogenation and in 1,2,3,4-tetrahydroquinoline hydrodenitrogenation (HDN) at 623 K, 3.5 MPa.

Influence of thermal treatment on the dispersion of MoS2 into MCM-41 and SBA-15 supports: TEM study and hydrotreating activity

MoS 2 catalysts supported on MCM-41 and SBA-15 were prepared by impregnation with ammonium heptamolybdate (≈8.0 wt % Mo) with the aim of obtaining a high Mo oxide dispersion, then a high MoS 2 dispersion after sulfidation for application in reaction of hydrodesulfurization. The influence of the thermal treatment (under air at 573 and at 723 and under He at 823K) on the nature and dispersion of the MoO x phase, and then of the sulfided phase was first studied with a commercial silica support, by X-ray diffraction, transmission electron microscopy and hydrodesufurization of dibenzothiophene. The best conditions of the thermal treatment, i.e. , under He at 823 K were then successfully applied for the preparation of MoS 2 /MCM-41 and MoS 2 /SBA-15 catalysts, which leads to a higher hydrodesulfurization activity of dibenzothiophene than with MoS 2 supported on commercial silica.