Fabrice Bertinchamps

Oxidation of 2-thiobenzyl-4,6-dimethyl-pyrimidine with hydrogen peroxide over Mo oxides, Mo suboxides and mixed Mo–Sb oxides catalysts

The oxidation of 2-thiobeniyl-4,6-dimethyl-pyrimidine was investigated over catalysts based on MoO3, Mo suboxides and mixed Mo-Sb oxides to obtain 2-thiobenzyl-4,6-dimethyl-pyrimidine sulfoxide. The chemoselectivity was found to vary with the oxidation state of the Mo atoms, the morphology of the Mo oxide crystals and the concentration of Sb in the structure. The best chemoselectivity (about 80%) resulted from Mo8O23. The H2O2 efficiency was also found to depend on these parameters. For Mo suboxides the best efficiency was obtained on Mo8O23, which suggested that the efficient catalysts are those possessing Mo in a reduced oxidation state. The presence of Sb changed the behavior of the catalysts and the higher H2O2 efficiency resulted for the catalysts containing Mo in its highest oxidation state

Synthesis of MTT zeolite catalysts with surface Al depletion

MTT zeolite crystals with siliceous layer on their external surface were synthesized using a two step hydrothermal procedure in which cores prepared from an aluminosilicate gel were transferred into a siliceous gel for farther crystal growth. The thickness of the siliceous shell was varied by varying the proportion of the two gels. The samples were characterized using physicochemical methods (XRD, XPS, 27Al MAS NMR, SEM, N2 adsorption). The zeolites were converted into bifunctional catalysts and evaluated in hydroisomerization of decane.