Comparative study on the structural and catalytic properties of mesoporous hexagonal silica anchored with H3PW12O40 : green synthesis of benzoic acid from benzaldehyde

摘要

Mesoporous silica anchored with 25 wt.% 12-tungstophosphoric acid (H3PW12O40, HPW) were comparatively characterized on their structures and catalytic activities for benzaldehyde oxidation with H2O2. The results revealed that the mesoporous materials retained the typical hexagonal mesopores for the supports of HPW. It was found that HPW exhibited higher dispersion within MCM-41 than those within SBA-15 and other mesoporous molecular sieves. Moreover, the as-prepared materials were found to be the efficient catalysts for the green synthesis of benzoic acid. In particular, HPW/MCM-41 exhibited the best catalytic properties due to its suitable textural and structural characteristics.