Efficiently coupled glucose oxidation for high-value D-glucaric acid with ultradurable hydrogen via Mn(III) in acidic solution

The electrooxidation of the alcohol and aldehyde molecules instead of water coupled with H2 production has been proven to be effective for producing high-value fine chemicals under alkaline conditions. It is also noteworthy that under acidic conditions, the stability of non-noble metal water oxidation catalysts remains a great challenge due to the lattice oxygen mechanism. Hence, we coupled the biomass-derived glucose oxidation for high-value D-glucaric acid (GRA) with ultra-durable hydrogen in acid solution over a Yb-MnO2 catalyst. The Mn3+ regulated by Yb atoms doped in MnO2 can effectively optimize the adsorption and desorption processes of the alcohol and aldehyde group and improve the intrinsic activity but cannot for H2O. The catalyst exhibited extremely high activity and stability after 50 h for glucose oxidation, inhibiting the lattice oxygen process and MnO4− formation, while the activity was quickly lost within 0.5 h for water oxidation. Density functional theory (DFT) calculations further demonstrated that glucose oxidation reaction proceeds preferentially due to the oxidation of aldehyde group with lower adsorption-free energy (−0.4 eV) than water (ΔG > 0 eV), avoiding the lattice oxygen mechanism. This work suggests that biomass-derived glucose oxidation not only provides a cost-effective approach for high-value chemicals, but also shows an extremely potential as an alternative to acidic oxygen evolution reaction (OER) for ultradurable H2 production.