Selective oxidation of benzyl alcohol to benzaldehyde with air using ZIF-67 derived catalysts

Development of efficient catalyst for conversion of benzyl alcohol to benzaldehyde using molecular oxygen is of great importance in virtue of the economic and environmentally friendly superiority. In this study, a cobalt-based zeolitic imidazolate framework, ZIF-67, has been used as precursor to synthesize different catalysts for study in benzyl alcohol oxidation by air. The catalysts were characterized by XRD, SEM, ICP-MS, N2 adsorption-desorption and XPS. The cobalt oxide catalyst, which was obtained via calcination of ZIF-67 in air, showed low activity and selectivity toward benzaldehyde. While the Co@CN, prepared from pyrolysis in argon, exhibited good activity and recyclability under mild conditions. The results suggested that the cobalt species, either metallic cobalt or Co2+, were the main active sites. In addition, the nitrogen species also played a role for the efficient conversion of benzyl alcohol. [Display omitted]