International Research Center for Renewable Energy, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, China.
Chem Commun (Camb). 2023 Feb 16;59(15):2138-2141. doi: 10.1039/d2cc05775a.
Conventional one-step water electrolyzers generate H accompanied by O evolution, and may cause gas mixing and high cell voltage inputs. Herein, using the potassium ion battery material of KMnO-Ti as a mediator, we effectively decoupled the H and O evolution of alkaline water electrolysis temporally, thereby achieving a membrane-free pathway for H production. As a mediator electrode for charge storage, the KMnO-Ti exhibited a stable capacity of 100 mA h g at 0.1 A g owing to the reversible K-ion insertion/extraction mechanism. The decoupled water electrolysis device exhibited the step voltages for hydrogen and oxygen production of 1.02 and 0.57 V at 5 mA, respectively. A nearly unity Faradaic efficiency and sustained production of pure H has been demonstrated at a constant current density. We anticipate that this mediator demonstrated here may provide a route for the practical application of the decoupling strategy.
传统的一步水电解槽会同时产生 H 和 O 的演化，并可能导致气体混合和高电池电压输入。在此，我们使用钾离子电池材料 KMnO-Ti 作为媒介，有效地将碱性水电解的 H 和 O 演化在时间上解耦，从而实现了一种无膜的 H 生产途径。作为电荷存储的媒介电极，KMnO-Ti 由于可逆的 K 离子插入/提取机制，在 0.1 A g 时表现出 100 mA h g 的稳定容量。解耦水电解装置在 5 mA 时分别表现出氢和氧产生的阶跃电压为 1.02 和 0.57 V。在恒定电流密度下，证明了近 100%的法拉第效率和纯 H 的持续生产。我们预计，这里展示的这种媒介可能为解耦策略的实际应用提供一条途径。
