An Integrated Cobalt-Polyoxoniobate for Catalytic Aldehyde Oxidation

The efficient aerobic oxidation of aldehydes under mild conditions is a persistent challenge in heterogeneous catalysis, constrained by mass transfer in gas-liquid-solid triphasic systems. Herein, we report a cobalt-containing polyoxoniobate (PONb) heterogeneous integrated catalyst, Co_0.6@Li₂K_3.8[Sb(H₂O)][GeNb₁₂O₄₀(V^VO)₂]·8H₂O (Co/FZU-3), that efficiently drives the additive-free aerobic oxidation of diverse aldehydes to carboxylic acids at room temperature, without external heating or cocatalysts. Co/FZU-3 delivers a record-high turnover frequency (TOF) of 333 h^-1 among reported catalysts, alongside excellent recyclability and gram-scale applicability. The excellent catalytic performance originates from an efficient proton transfer process, synergistically enabled by the stable anchoring of active cobalt centers and the outstanding proton-conducting capability of the PONb framework. This work not only addresses key efficiency bottlenecks in triphasic aerobic oxidation but also demonstrates a design strategy for multifunctional, green catalytic systems.