Efficient catalytic oxidation of alcohol to carbonyl compounds over CoFe hydrotalcites

摘要

A series of CO32- -CoxFe-LDHs (x = 2, 3, 4 and 5) compounds with different Co/Fe ratios have been prepared, characterized and introduced into the selective oxidation of alcohols by tert-butylhydroperoxide. The characterization including XRD, SEM, FTIR, TG/DTG, DR UV-vis, N-2 adsorption and XPS showed that the hydrotalcite structure was well formed with different Co/Fe ratios, and the ratio has significant influence on the materials' morphologies, physical properties and the composition of Co2+/Co3+/Fe3+. The effects of varied reaction conditions on the catalytic oxidation have been investigated, and the results indicate that the co-existence of Co2+ and Co3+ is beneficial to the catalytic activity. Comparison experiments showed that substitution of Al with Fe could markedly increase the surface area of the material, and a synergistic effect might exist between Co and Fe in the CoFe hydrotalcites for the alcohol oxidation. In addition, the catalyst also exhibited excellent stability and catalytic performance in the oxidation of varied alcohols.