Nanocrystalline gold supported on Fe-, Ti- and Ce-modified hexagonal mesoporous silica as a catalyst for the aerobic oxidative esterification of benzyl alcohol Original Research Article

The materials containing gold nanoparticles supported on pure and Ce, Ti, or Fe-modified hexagonal mesoporous silica were prepared and their structural and electronic properties were studied by XRD, TEM, XPS, and N2 adsorption techniques. The materials were shown to be effective heterogeneous catalysts for the liquid-phase aerobic oxidation of benzyl alcohol in methanol solutions. It was found that the modifiers significantly improve the catalytic properties of supported gold particles and allow performing the selective one-pot oxidative esterification of benzyl alcohol resulting in methyl benzoate. The modified catalysts exhibited high activity (turnover frequencies of up to ca. 1000 h−1), selectivity to methyl benzoate (up to 95%), and stability (turnover numbers of up to ca. 4300). Ce and Ti were found to be more effective promoters as compared with Fe in terms of catalyst stability.