Water electrolysis to produce H₂ is a promising strategy for generating a renewable fuel. However, the sluggish-kinetics and low value-added anodic oxygen evolution reaction (OER) restricts the overall energy conversion efficiency. Herein we report a strategy of boosting H₂ production at low voltages by replacing OER with a bioelectrochemical cascade reaction at a triphase bioanode. In the presence of oxygen, oxidase enzymes can convert biomass into valuable products, and concurrently generate H₂O₂ that can be further electrooxidized at the bioanode. Benefiting from the efficient oxidase kinetics at an oxygen-rich triphase bioanode and the more favorable thermodynamics of H₂O₂ oxidation than that of OER, the cell voltage and energy consumption are reduced by ~0.70 V and ~36%, respectively, relative to regular water electrolysis. This leads to an efficient H₂ production at the cathode and valuable product generation at the bioanode. Integration of a bioelectrochemical cascade into the water splitting process provides an energy-efficient and promising pathway for achieving a renewable fuel.

电解水生产 H ₂是一种很有前途的可再生燃料生产策略。然而，缓慢的动力学和低附加值的阳极析氧反应（OER）限制了整体能量转换效率。在此，我们报告了一种通过在三相生物阳极用生物电化学级联反应代替 OER来提高低压下 H _{2产量的策略。}在氧气存在的情况下，氧化酶可以将生物质转化为有价值的产品，同时生成可以在生物阳极进一步电氧化的H ₂ O _{2 。}受益于富氧三相生物阳极的高效氧化酶动力学和更有利的 H ₂ O _2热力学与 OER 相比，相对于常规水电解，电池电压和能耗分别降低了约 0.70 V 和约 36%。这导致在阴极产生高效的 H ₂并在生物阳极产生有价值的产物。将生物电化学级联集成到水分解过程中为实现可再生燃料提供了一种节能且有前途的途径。