Yang Chunzhen, Rousse Gwenaëlle, Louise Svane Katrine, Pearce Paul E, Abakumov Artem M, Deschamps Michael, Cibin Giannantonio, Chadwick Alan V, Dalla Corte Daniel Alves, Anton Hansen Heine, Vegge Tejs, Tarascon Jean-Marie, Grimaud Alexis
Chimie du Solide et de l'Energie, UMR 8260, Collège de France, 75231 Cedex 05, Paris, France.
State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China.
Nat Commun. 2020 Mar 13;11(1):1378. doi: 10.1038/s41467-020-15231-x.
The production of hydrogen at a large scale by the environmentally-friendly electrolysis process is currently hampered by the slow kinetics of the oxygen evolution reaction (OER). We report a solid electrocatalyst α-LiIrO which upon oxidation/delithiation chemically reacts with water to form a hydrated birnessite phase, the OER activity of which is five times greater than its non-reacted counterpart. This reaction enlists a bulk redox process during which hydrated potassium ions from the alkaline electrolyte are inserted into the structure while water is oxidized and oxygen evolved. This singular charge balance process for which the electrocatalyst is solid but the reaction is homogeneous in nature allows stabilizing the surface of the catalyst while ensuring stable OER performances, thus breaking the activity/stability tradeoff normally encountered for OER catalysts.
目前，通过环境友好型电解过程大规模生产氢气受到析氧反应（OER）缓慢动力学的阻碍。我们报道了一种固体电催化剂α-LiIrO，它在氧化/脱锂时与水发生化学反应，形成水合钠水锰矿相，其OER活性比未反应的对应物高五倍。该反应涉及一个体相氧化还原过程，在此过程中，来自碱性电解质的水合钾离子插入结构中，同时水被氧化并释放出氧气。这种独特的电荷平衡过程中，电催化剂是固体，但反应本质上是均相的，这使得催化剂表面得以稳定，同时确保了稳定的OER性能，从而打破了OER催化剂通常面临的活性/稳定性权衡。
