Scalable synthesis of a new {P2Mo18O62}-modified CuI/CuII-based metal–organic complex for multi-center synergistic catalysis of benzyl alcohol to benzoic acid

Abstract

The scalable production of high-efficiency catalysts derived from polyoxometalates (POMs) is critically significant for advancing the catalysis sector. Herein, the synthesis of a new [P2Mo18O62]6– ({P2Mo18})-based metal–organic complex, (CuIL2)11[(CuIIL2Cl)(P2Mo18O62)2]·2L·0.5H2O (L = benzimidazole) (1), was achieved on a large scale using the one-pot method, and the complex was systematically characterized. Complex 1 is a three-dimensional (3D) supramolecular framework by hydrogen bonding interactions between [CuII0.5LCl0.5]-decorated {P2Mo18} anions and {CuIL2} metal–organic subunits. Benzyl alcohol (BA) was efficiently oxidized to benzoic acid (BZA) with complex 1 as a stable heterogeneous catalyst, exhibiting a remarkable conversion rate of nearly 100 % and an outstanding selectivity of 99.47 %. Notably, the catalytic system exhibits outstanding scalability, with no significant decrease in conversion and selectivity after a 20-fold increase in reaction scale. The remarkable efficiency is attributable to the unique multi-center synergistic catalytic mechanism of CuI, CuII, and MoVI within complex 1. These findings could provide significant insights into the rational design and synthesis of POMs-based catalytic materials with enhanced catalytic efficiency.