Development of an integrated polyoxoniobate catalyst with oxygen activation and basicity as a green catalyst for efficient aerobic oxidation of aldehydes at room temperature†

Abstract

This work developed an inorganic–organic hybrid integrated polyoxoniobate (PONb) heterogeneous catalyst, representing the first instance of achieving efficient aldehyde oxidation using a single catalyst and clean O₂ as the oxidant, without the need for high temperatures or additional co-catalysts. The catalyst exhibited excellent scalability for gram-scale reactions and proved to be recyclable. Its remarkable catalytic performance arises from the synergistic interplay of three key components within the integrated catalyst: cobalt complex cations serve as active sites for oxygen activation, Nb-oxo polyoxoanions provide Brønsted basicity, and lattice water molecules enhance efficient mass transfer across the liquid–solid interface. This integrated catalyst not only overcomes the bottleneck of low reaction efficiency in the gas–solid–liquid triphasic system for heterogeneous aerobic oxidation of aldehydes, but also provides a novel design strategy for green catalysis.