Surface enrichment of Ir on the IrRu alloy for efficient and stable water oxidation catalysis in acid

Junming Zhang; Xueli Cao; Ya-Fei Jiang; Sung-Fu Hung; Wei Liu; Hong Bin Yang; Cong-Qiao Xu; Dong-Sheng Li; Tianyu Zhang; Yujing Li; Jun Li; Bin Liu

doi:10.1039/d2sc03947h

Surface enrichment of Ir on the IrRu alloy for efficient and stable water oxidation catalysis in acid

Chem Sci. 2022 Sep 22;13(41):12114-12121. doi: 10.1039/d2sc03947h. eCollection 2022 Oct 26.

Authors

Junming Zhang¹, Xueli Cao², Ya-Fei Jiang³, Sung-Fu Hung⁴, Wei Liu⁵, Hong Bin Yang⁵, Cong-Qiao Xu³, Dong-Sheng Li⁶, Tianyu Zhang⁷, Yujing Li⁸, Jun Li^{3

9}, Bin Liu¹

Affiliations

¹ School of Chemical and Biomedical Engineering, Nanyang Technological University Singapore 637459 Singapore liubin@ntu.edu.sg.
² Department of Chemistry, Zhejiang University Hangzhou 310027 China.
³ Department of Chemistry, Southern University of Science and Technology Shenzhen 518055 China.
⁴ Department of Applied Chemistry, National Yang Ming Chiao Tung University Hsinchu 300 Taiwan.
⁵ Dalian Institute of Chemical Physics, Chinese Academy of Sciences Dalian 116023 China.
⁶ College of Materials and Chemical Engineering, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, China Three Gorges University Yichang 443002 China.
⁷ College of Environmental Science and Engineering, Beijing Forestry University Beijing 100083 China tzhang@bjfu.edu.cn.
⁸ School of Materials Science and Engineering, Beijing Institute of Technology Beijing 100081 China yjli@bit.edu.cn.
⁹ Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University Beijing 100084 China.

Abstract

Inducing the surface enrichment of active noble metal can not only help to stabilize the catalyst but also modify the catalytic performance of the catalyst through electronic and geometric effects. Herein, we report the in situ surface enrichment of Ir on IrRu alloy during the oxygen evolution reaction (OER). The surface enrichment of Ir was probed by ex situ high-resolution transmission electron microscopy (HRTEM), in situ X-ray absorption spectroscopy (XAS), and electrochemical Cu stripping, leading to complementary characterizations of the dynamic reconstruction of the IrRu alloy during OER. Guided by the density functional theory (DFT), an IrRu alloy with low Ir content (20 wt%) was constructed, which displayed a low overpotential of only 230 mV to deliver an OER current density of 10 mA cm^-2 in 0.1 M HClO₄ solution and maintained stable performance for over 20 h. To investigate the practical application potential, a proton exchange membrane (PEM) water electrolyzer using the IrRu alloy as the anode catalyst was assembled, which required a low cell voltage of only 1.48 V to generate a current density of 1 A cm^-2.