Electronically Asymmetric Ruthenium Clusters Promote Lignocellulose Photoreforming for Simultaneous H2 Evolution and Biochemical Production

Solar-driven coproduction of H2 and value-added biochemicals from lignocellulosic biomass offers a promising route to address energy challenges. Ruthenium (Ru) is a cost-effective alternative to platinum for photocatalytic H2 production, yet its efficiency in lignocellulose photoreforming is limited by sluggish proton-coupled electron transfer and slow oxidation kinetics of recalcitrant substrates. Here, we engineer Ru clusters on supramolecular carbon nitride (CN) via stepwise annealing reduction, creating Ru–N and Ru–Ru motifs with intracluster electronic asymmetry. Tuning the reduction temperature optimizes charge partitioning between high-valence Run+ and metallic Ru0 sites, enabling efficient photoreforming. The optimized catalyst achieves a H2 evolution rate of 1609.82 μmol g–1 h–1 in the presence of cellulose, corresponding to 2- and 54-fold enhancements over conventional Ru-loaded CN and pristine CN, respectively. Spectroscopic analyses suggest that the asymmetric electronic structure promotes H2O adsorption and dissociation at electron-deficient Run+ sites and facilitates charge separation and migration, while electron-rich Ru0 sites promote O2 reduction to •O2–. Reactive-species analyses indicate that •O2–, h+, and •OH participate in lignocellulose oxidation. This work presents an effective strategy for simultaneous green H2 and value-added biochemical production via lignocellulose photoreforming.