Rong Chengli, Shen Xiangjian, Wang Yuan, Thomsen Lars, Zhao Tingwen, Li Yibing, Lu Xunyu, Amal Rose, Zhao Chuan
School of Chemistry, The University of New South Wales, Sydney, NSW, 2052, Australia.
Engineering Research Centre of Advanced Functional Material Manufacturing of Ministry of Education, Zhengzhou University, Zhengzhou, 450001, P. R. China.
Adv Mater. 2022 May;34(21):e2110103. doi: 10.1002/adma.202110103. Epub 2022 Apr 24.
The development of bifunctional water-splitting electrocatalysts that are efficient and stable over a wide range of pH is of great significance but challenging. Here, an atomically dispersed Ru/Co dual-sites catalyst is reported anchored on N-doped carbon (Ru/Co-N-C) for outstanding oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in both acidic and alkaline electrolytes. The Ru/Co-N-C catalyst requires the overpotential of only 13 and 23 mV for HER, 232 and 247 mV for OER to deliver a current density of 10 mA cm in 0.5 m H SO and 1 m KOH, respectively, outperforming benchmark catalysts Pt/C and RuO . Theoretical calculations reveal that the introduction of Co-N4 sites into Ru/Co-N-C efficiently modify the electronic structure of Ru by enlarging Ru-O covalency and increasing Ru electron density, which in turn optimize the bonding strength between oxygen/hydrogen intermediate species with Ru sites, thereby enhancing OER and HER performance. Furthermore, the incorporation of Co-N4 sites induces electron redistribution around Ru-N4, thus enhancing corrosion-resistance of Ru/Co-N-C during acid and alkaline electrolysis. The Ru/Co-N-C has been applied in a proton exchange membrane water electrolyzer and steady operation is demonstrated at a high current density of 450 mA cm for 330 h.
开发在广泛pH范围内高效且稳定的双功能析水电催化剂具有重要意义，但极具挑战性。在此，报道了一种原子分散的Ru/Co双位点催化剂，其锚定在氮掺杂碳上（Ru/Co-N-C），在酸性和碱性电解质中均具有出色的析氧反应（OER）和析氢反应（HER）性能。Ru/Co-N-C催化剂在0.5 M H₂SO₄和1 M KOH中分别达到10 mA cm⁻²电流密度时，HER的过电位仅为13和23 mV，OER的过电位为232和247 mV，性能优于基准催化剂Pt/C和RuO₂。理论计算表明，将Co-N₄位点引入Ru/Co-N-C中，通过扩大Ru-O共价性和增加Ru电子密度，有效地改变了Ru的电子结构，进而优化了氧/氢中间物种与Ru位点之间的键合强度，从而提高了OER和HER性能。此外，Co-N₄位点的引入导致Ru-N₄周围的电子重新分布，从而增强了Ru/Co-N-C在酸碱电解过程中的耐腐蚀性。Ru/Co-N-C已应用于质子交换膜水电解槽，并在450 mA cm⁻²的高电流密度下稳定运行330小时。
