Physical properties and catalytic behaviour of sulfate-vanadium modified silica-titania aerogel

Both vanadium and sulfate modified silica-titania aerogels have shown excellent catalytic performance as bifunctional catalysts in producing diols from 1-octene. Pyridine adsorption study revealed the increase of Brønsted acid sites in sulfated vanadium loaded silica-titania aerogel (SO4_V/ST) as compared to that of sulfated silica-titania aerogel (SO4/ST). This phenomenon could be resulted from synergy effect of co-existence of sulfate and vanadium on the surface of silica-titania. In contrast, no noticeable Brønsted acidity was detected in vanadium solely loaded silica-titania aerogel (V/ST). The catalyst results, however, showed that SO4/ST was a better bifunctional catalyst, followed by V/ST and SO4_V/ST. The formation of vanadium sulfate (VOSO4) may have retarded the catalytic activity of SO4_V/ST