Orbital coupling of hetero-diatomic nickel-iron site for bifunctional electrocatalysis of CO2 reduction and oxygen evolution

Zhiping Zeng; Li Yong Gan; Hong Bin Yang; Xiaozhi Su; Jiajian Gao; Wei Liu; Hiroaki Matsumoto; Jun Gong; Junming Zhang; Weizhen Cai; Zheye Zhang; Yibo Yan; Bin Liu; Peng Chen

doi:10.1038/s41467-021-24052-5

Orbital coupling of hetero-diatomic nickel-iron site for bifunctional electrocatalysis of CO₂ reduction and oxygen evolution

Nat Commun. 2021 Jul 2;12(1):4088. doi: 10.1038/s41467-021-24052-5.

Authors

Zhiping Zeng^{1

2}, Li Yong Gan³, Hong Bin Yang⁴, Xiaozhi Su⁵, Jiajian Gao², Wei Liu⁶, Hiroaki Matsumoto⁷, Jun Gong², Junming Zhang², Weizhen Cai², Zheye Zhang², Yibo Yan⁸, Bin Liu⁹, Peng Chen¹⁰

Affiliations

¹ State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, China.
² School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore.
³ Institute for Structure and Function, Department of Physics, Chongqing University, Chongqing, China.
⁴ Institute for Materials Science and Devices, Suzhou University of Science and Technology, Suzhou, China. yanghb@mail.usts.edu.cn.
⁵ Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, CAS, Shanghai, China.
⁶ Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China.
⁷ Hitachi High-Technologies (Shanghai) Co. Ltd., Shanghai, People's Republic of China.
⁸ Shaanxi Institute of Flexible Electronics, Northwestern Polytechnical University, Xi'an, China.
⁹ School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore. liubin@ntu.edu.sg.
¹⁰ School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore. chenpeng@ntu.edu.sg.

Abstract

While inheriting the exceptional merits of single atom catalysts, diatomic site catalysts (DASCs) utilize two adjacent atomic metal species for their complementary functionalities and synergistic actions. Herein, a DASC consisting of nickel-iron hetero-diatomic pairs anchored on nitrogen-doped graphene is synthesized. It exhibits extraordinary electrocatalytic activities and stability for both CO₂ reduction reaction (CO₂RR) and oxygen evolution reaction (OER). Furthermore, the rechargeable Zn-CO₂ battery equipped with such bifunctional catalyst shows high Faradaic efficiency and outstanding rechargeability. The in-depth experimental and theoretical analyses reveal the orbital coupling between the catalytic iron center and the adjacent nickel atom, which leads to alteration in orbital energy level, unique electronic states, higher oxidation state of iron, and weakened binding strength to the reaction intermediates, thus boosted CO₂RR and OER performance. This work provides critical insights to rational design, working mechanism, and application of hetero-DASCs.