Modulating the electronic structure of Co-Ni bimetal oxides on mesoporous silica for promoting selective oxidation of alcohol

The selective oxidation of alcohols by transition-metal-based catalysts provides a green route for the production of aldehydes. In this paper, mesoporous SBA-15 supported bimetallic Ni x Co y oxides were synthesized for the catalytic oxidation of alcohol using oxygen as the sole oxidant. The catalytic activity was highly related to the metal composition, of which the Ni 1 Co 4 /SBA-15 catalyst showed the best catalytic performance with high benzyl alcohol conversion of 96.2% and benzaldehyde selectivity of 98.3%. It was proposed that the electronic structure of the Ni x Co y /SBA-15 catalysts can be modulated by Ni/Co ratio, and high Co 3+ /Co 2+ and Ni 3+ /Ni 2+ ratios promoted the catalyst activity. Compared to the Ni x Co y nanocatalysts obtained by removing SBA-15 support, the Ni x Co y /SBA-15 exhibited a better benzyl alcohol oxidation performance, suggesting a diffusion enhancement by the mesoporous structure of SBA-15 support.