Facile synthesis of polyoxometalate-intercalated layered double hydroxide as efficient catalyst for benzyl alcohol oxidation

Selective alcohol oxidation is a fundamental transformation in organic chemistry, facilitating the production of carbonyl compounds that act as essential intermediates in a myriad of chemical syntheses. In particular, aerobic oxidation of benzyl alcohol (BA) to benzaldehyde is highly valuable for applications within the chemical industry, pharmaceutical chemistry, and the synthesis of functional polymers. However, despite the availability of conventional oxidation methodologies, attaining high selectivity and yield for benzaldehyde remains a significant challenge. Polyoxometalates (POMs), a widely used inorganic anionic transition metal oxides, have demonstrated considerable potential as catalysts for BA oxidation. Nonetheless, their practical application is often restricted by issues, including low surface area and poor recyclability. To overcome these obstacles, immobilizing POMs onto layered double hydroxides (LDHs)—which possess modular architectures that enhance catalytic activity and selectivity—has emerged as a promising approach. Here, we present a novel "one-pot" anion-exchange technique to incorporate the [P₂W₁₇ZnO₆₁]⁸⁻ cluster into tris(hydroxymethyl)aminomethane modified LDHs (TrisLDHs). The synthesized material, Tris-LDHs-P₂W₁₇Zn, achieved complete conversion of BA with a selectivity of 92.46% for benzaldehyde using H₂O₂ as the oxidant, thereby offering a practical solution for selective oxidation of BA.