Physicochemical properties of V/Ti-PILC: effect of V loading in selective oxidation of benzyl alcohol

Abstract

Mineral clays are attractive as catalysts due to their low cost and high availability. In this sense, Ti-PILCs were synthesized, which were later modified with different vanadium contents (0.1, 0.5 and 1% by weight). All the pillared materials presented higher basal spacing and specific area with respect to the original clay (Na-mont), which allowed a good dispersion of the incorporated V species.
The V/Ti-PILC catalysts showed a higher benzyl alcohol (BzOH) conversion than Ti-PILC, which improved when the vanadium load increased to 0.5 % by weight, reaching a value of 42.82 % mol after 5 h of reaction. This fact could be attributed to the presence of highly dispersed isolated V ions in tetrahedral coordination. On the other hand, the decrease in the conversion of BzOH with V(1%)/Ti-PILC, would be associated both to the presence of polymeric V species (observed by UV-vis-RD) and to the decrease of the specific area due to the pore blocking by V species. For the most active catalyst, V(0.5%)/Ti-PILC, the selectivity to benzaldehyde (BzH) reached a value of 94.72 % mol after 5 h of reaction.