文献类型：期刊文献

英文题名：Tuning the hybridization state of Ir-O to improve the OER activity and stability of iridium pyrochlore via Zn doping

作者：Zhu, Lin[1];Ma, Chenglong[1];Wang, Zhiqiang[2,3];Gong, Xueqing[2,3];Cao, Limei[1];Yang, Ji[1,4]

机构：[1]East China Univ Sci & Technol, Sch Resources & Environm Engn, State Environm Protect Key Lab Environm Risk Asse, 130 Meilong Rd, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Key Lab Adv Mat & Joint Int Res Lab Precis Chem &, Feringa Nobel Prize Scientist Joint Res Ctr, Ctr Computat Chem, Shanghai 200237, Peoples R China;[3]East China Univ Sci & Technol, Res Inst Ind Catalysis, Sch Chem & Mol Engn, Shanghai 200237, Peoples R China;[4]Shanghai Inst Pollut Control & Ecol Secur, Shanghai 200092, Peoples R China

年份：2022

卷号：576

外文期刊名：APPLIED SURFACE SCIENCE

收录：;EI(收录号：20214611166607);WOS:【SCI-EXPANDED(收录号:WOS:000729816000007)】；

基金：This research is based on work supported by the National Natural Science Foundation of China (21277045) , China Postdoctoral Science Foundation (2020 M671020) , and the National Natural Science Foun-dation of China (51778229) . In addition, we are grateful for the Research Center of Analysis and Test of East China University of Science and Technology for characterization analysis of materials and the Na-tional Synchrotron Radiation Laboratory (NSRL, Beamline BL11U) . This study was also supported by Feringa Nobel Prize Scientist Joint Research Center.

语种：英文

外文关键词：Oxygen evolution reaction; Electrocatalyst; Pyrochlore oxides; Water splitting

摘要：Developing high-active, stable, and cost-efficient electrocatalysts for oxygen evolution reaction (OER) is urgent task in water splitting. Recently, iridium pyrochlores (A(2)Ir(2)O(7)) have attracted broad attention as promising catalysts due to their unique electronic properties and the less iridium content relative to IrO2, while in iridium pyrochlores, the relatively high concentration of oxygen vacancies decreases the Ir-O hybridization, hindering the OER process. The electronic states of iridium-based pyrochlore M2Ir2O7 (M = Lu, Pr) are rationally tuned through partial substitution in A-site of Zn2+ for Lu3+ or Pr3+, efficiently promoting its intrinsic activity. The optimal Pr1.8Zn0.2Ir2O7 and Lu1.8Zn0.2Ir2O7 electrocatalysts exhibit 114.6 and 135.32 A g(Ir)(-1) high mass activity at 1.58 V vs. RHE. Combining X-ray absorption spectrum with DFT calculations, we demonstrate that the doping of Zn2+ reduces the defective oxygen and regulates the electron distribution. The decrease of defective oxygen leads to the O-2p band center upshift, resulting in the Ir-O covalency promotion and the decrease of the binding energy between oxygen intermediates and Ir to accelerate the OER process. This work provides a fresh idea introducing small ionic radius Zn to solve the problem of high concentration of oxygen vacancies inevitably produced in the synthesis of pyrochlores.