Dynamic Behavior of Single-Atom Catalysts in Electrocatalysis: Identification of Cu-N3 as an Active Site for the Oxygen Reduction Reaction

被引：379

作者：

Yang, Ji ^{[1
,2
,3
]}

Liu, Wengang ^{[2
]}

Xu, Mingquan ^{[4
,5
]}

Liu, Xiaoyan ^{[2
]}

Qi, Haifeng ^{[2
]}

Zhang, Leilei ^{[2
]}

Yang, Xiaofeng ^{[2
]}

Niu, Shanshan ^{[2
]}

Zhou, Dan ^{[2
]}

Liu, Yuefeng ^{[2
]}

Su, Yang ^{[2
]}

Li, Jian-Feng ^{[3
]}

Tian, Zhong-Qun ^{[3
]}

Zhou, Wu ^{[4
,5
,6
]}

Wang, Aiqin ^{[1
,2
]}

Zhang, Tao ^{[1
,2
]}

机构：

[1] Chinese Acad Sci, Dalian Inst Chem Phys, Collaborat Innovat Ctr Chem Energy Mat iChEM, Dalian 116023, Peoples R China

[2] Chinese Acad Sci, Dalian Inst Chem Phys, CAS Key Lab Sci & Technol Appl Catalysis, Dalian 116023, Peoples R China

[3] Xiamen Univ, Collaborat Innovat Ctr Chem Energy Mat iChEM, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China

[4] Univ Chinese Acad Sci, Sch Phys Sci, Beijing 100049, Peoples R China

[5] Univ Chinese Acad Sci, CAS Key Lab Vacuum Phys, Beijing 100049, Peoples R China

[6] Univ Chinese Acad Sci, CAS Ctr Excellence Topol Quantum Computat, Beijing 100049, Peoples R China

来源：

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | 2021年 / 143卷 / 36期

基金：

中国国家自然科学基金;

关键词：

N-C CATALYST; FUEL-CELL; COPPER; PERFORMANCE; OXIDATION; EFFICIENT; GRAPHENE; CATHODE; COMPLEXES; BATTERIES;

D O I：

10.1021/jacs.1c03788

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Atomically dispersed M-N-C (M refers to transition metals) materials represent the most promising catalyst alternatives to the precious metal Pt for the electrochemical reduction of oxygen (ORR), yet the genuine active sites in M-N-C remain elusive. Here, we develop a two-step approach to fabricate Cu-N-C single-atom catalysts with a uniform and well-defined Cu2+-N-4 structure that exhibits comparable activity and superior durability in comparison to Pt/C. By combining operando X-ray absorption spectroscopy with theoretical calculations, we unambiguously identify the dynamic evolution of Cu-N-4 to Cu-N-3 and further to HO-Cu-N-2 under ORR working conditions, which concurrently occurs with reduction of Cu2+ to Cu+ and is driven by the applied potential. The increase in the Cu+/Cu2+ ratio with the reduced potential indicates that the low-coordinated Cu+-N-3 is the real active site, which is further supported by DFT calculations showing the lower free energy in each elemental step of the ORR on Cu+-N-3 than on Cu2+-N-4. These findings provide a new understanding of the dynamic electrochemistry on M-N-C catalysts and may guide the design of more efficient low-cost catalysts.

引用

页码：14530 / 14539

页数：10

共 58 条

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