On-Demand CatalyticPlatform for Glycerol Upgradeand Utilization

Surplus byproducts generated during biomass exploitation, such as glycerol from biodiesel manufacturing, seriously undermine the credibility of renewable energy policies. Here, we establish an on-demand catalytic platform for the upgrade and utilization of glycerol via photoelectro-bioelectro-heterogeneous coupling catalysis. Combining theoretical descriptors, specifically the highest occupied molecular orbital energy levels and dual local softness values, along with systematic experimental validation, we demonstrated the reaction activity of glycerol and its upgraded products on BiVO₄ photoelectrodes. Glyceric acid was identified as the optimal biofuel candidate through monohydroxyl oxidation of glycerol. Coupling the preferential upgrading of glycerol to glyceric acid by night and its reuse as biofuel by day, a hybrid biophotoelectrochemical system delivered an open-circuit voltage of 0.89 ± 0.02 V and a maximum power density of 0.41 ± 0.03 mW cm^–2 with stable diurnal operation for over 10 days. This successful model construction provides valuable insights into the strategic integration of multiple energy sources and the exploration of coupling-catalytic platforms, charting new territory for the next-generation sustainable energy systems.