The voltage penalty driving water dissociation (WD) at high current density is a major obstacle in the commercialization of bipolar membrane (BPM) technology for energy devices. Here we show that three materials descriptors, that is, electrical conductivity, microscopic surface area and (nominal) surface-hydroxyl coverage, effectively control the kinetics of WD in BPMs. Using these descriptors and optimizing mass loading, we design new earth-abundant WD catalysts based on nanoparticle SnO₂ synthesized at low temperature with high conductivity and hydroxyl coverage. These catalysts exhibit exceptional performance in a BPM electrolyser with low WD overvoltage (η_wd) of 100 ± 20 mV at 1.0 A cm⁻². The new catalyst works equivalently well with hydrocarbon proton-exchange layers as it does with fluorocarbon-based Nafion, thus providing pathways to commercializing advanced BPMs for a broad array of electrolysis, fuel-cell and electrodialysis applications.

高电流密度下驱动水解离（WD）的电压损失是能源器件双极膜（BPM）技术商业化的主要障碍。在这里，我们展示了三种材料描述符，即电导率、微观表面积和（标称）表面羟基覆盖率，可以有效控制 BPM 中的 WD 动力学。利用这些描述符和优化质量负载，我们设计了基于低温合成的纳米颗粒 SnO ₂ 的新型 WD 催化剂，该催化剂具有高电导率和羟基覆盖率。这些催化剂在 BPM 电解槽中表现出卓越的性能，在 1.0 A cm ⁻² 下 WD 过电压 (η _wd ) 为 100 ± 20 mV。这种新型催化剂与碳氢化合物质子交换层的配合效果与碳氟化合物基 Nafion 的配合效果相当，从而为先进 BPM 的商业化提供了途径，可用于广泛的电解、燃料电池和电渗析应用。