Electronic Structure Engineering of Single‐Atom Ru Sites via Co–N4 Sites for Bifunctional pH‐Universal Water Splitting. Issue 21 (24th April 2022)

• Record Type: Journal Article
• Authors: Rong, Chengli; Shen, Xiangjian; Wang, Yuan; Thomsen, Lars; Zhao, Tingwen; Li, Yibing; Lu, Xunyu; Amal, Rose; Zhao, Chuan
• Is Part Of: Advanced materials. Volume 34:Issue 21(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-04-24
• Subjects: electrochemical energy conversion -- hydrogen -- ruthenium cobalt -- single‐atom catalysts -- water splitting; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202110103
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: 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 cmgeo −2 in 0.5 m H2 SO4 and 1 m KOH, respectively, outperforming benchmark catalysts Pt/C and RuO2 . 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 cmgeo −2 for 330 h. Abstract : Atomically dispersed Ru and Co dual‐sites anchored on N‐doped carbon (Ru/Co–N–C) is developed as an efficient and robust bifunctional electrocatalyst for pH‐universal water splitting.