Vanadium-containing SBA-15 systems prepared by direct synthesis: physicochemical and catalytic properties in the decomposition of dichloromethane
Résumé
Vx/SBA-15 catalysts (V content = 0.7-4.8 wt.%) were directly synthesized and tested for the oxidative decompn. of dichloromethane; impregnation-synthesized SBA-15 and V/SBA-15 catalysts were ref. samples. Catalyst structural and surface properties were characterized by complementary physicochem. techniques. Vx/SBA-15 materials with isolated V sites were catalytically active for dichloromethane decompn.; max. conversion was obtained by a catalyst with 2.2 wt.% V. In Vx/SBA-15 catalysts prepd. by direct synthesis, V occurred mainly as isolated sites with tetrahedral coordination; its content did not reach the theor. monolayer capacity (~4 wt.%). Unlike impregnation-synthesized catalysts, oligomeric VOx species formed only at high V content. [on SciFinder(R)]