Effect of Mg2 + on the catalytic activities of CoMgAl hydrotalcites in the selective oxidation of benzyl alcohol to benzaldehyde

•Co2MgxAl-LDHs with different Mg2 + contents were introduced to the oxidation of benzyl alcohol.•The basicity of the catalyst could contributes to the high selectivity of aldehyde in the reaction.•Introducing Mg2 + ions can promote the oxidation process of Co2 + to Co3 +.•The improved catalytic activities might be ascribed to the co-existence of Co2 + and Co3 +.

With the knowledge the significant effect of basic site on the catalytic performance of heterogeneous catalysts in the selective oxidation of alcohol, a series of Co2MgxAl-LDHs (x = 0, 0.5, 1.0, 1.5, and 2.0) compounds with different Mg2 + contents have been prepared, characterized and introduced into the selective oxidation of benzyl alcohol with TBHP as the oxidant. The results showed that introducing Mg2 + ions can not only influence the amount of basic site, but also promote the oxidation process of Co2 + to Co3 +. These facts must contribute to the markedly improved catalytic activities of Co2MgxAl-LDH samples.

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