Unpaired 3d Electrons on Atomically Dispersed Cobalt Centres in Coordination Polymers Regulate both Oxygen Reduction Reaction (ORR) Activity and Selectivity for Use in Zinc-Air Batteries

Yuebin Lian; Wenjuan Yang; Chufeng Zhang; Hao Sun; Zhao Deng; Wenjie Xu; Li Song; Zhongwen Ouyang; Zhenxing Wang; Jun Guo; Yang Peng

doi:10.1002/anie.201910879

Unpaired 3d Electrons on Atomically Dispersed Cobalt Centres in Coordination Polymers Regulate both Oxygen Reduction Reaction (ORR) Activity and Selectivity for Use in Zinc-Air Batteries

Angew Chem Int Ed Engl. 2020 Jan 2;59(1):286-294. doi: 10.1002/anie.201910879. Epub 2019 Nov 14.

Authors

Yuebin Lian^{1

2}, Wenjuan Yang³, Chufeng Zhang^{1

2}, Hao Sun^{1

2}, Zhao Deng^{1

2}, Wenjie Xu⁴, Li Song⁴, Zhongwen Ouyang⁵, Zhenxing Wang⁵, Jun Guo⁶, Yang Peng^{1

2}

Affiliations

¹ Soochow Institute of Energy and Material Innovations, College of Physics, Optoelectronics and Energy, Soochow University, Suzhou, 215006, China.
² Provincial Key Laboratory for Advanced Carbon Materials and Wearable Energy Technologies, Soochow University, Suzhou, 215006, China.
³ International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education, Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen, 518060, China.
⁴ National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei, Anhui, 230029, China.
⁵ Wuhan National High Magnetic Field Center & School of Physics, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China.
⁶ Analysis and Testing Center, Soochow University, Suzhou, 215123, China.

PMID: 31638312
DOI: 10.1002/anie.201910879

Abstract

Reversible oxygen conversion is important for various green energy technologies. Herein we synthesize a series of bimetallic coordination polymers by varying the Ni/Co ratio and using HITP (HITP=2,3,6,7,10,11-hexaiminotriphenylene) as the ligand, to interrogate the role of metal centres in modulating the activity of the oxygen reduction reaction (ORR). Co₃ HITP₂ and Ni₃ HITP₂ are compared. Unpaired 3d electrons in Co₃ HITP₂ result in less coplanarity but more radical character. Thus, despite of a reduced crystallinity and conductivity, the best ORR activity, comparable to 20 % Pt/C, is obtained for Co₃ HITP₂ , showing the 3d orbital configuration of the metal centre promotes ORR. Experimental and DFT studies show a transition of ORR pathway from four-electron for Co₃ HITP₂ to two-electron for Ni₃ HITP₂ . Rechargeable zinc-air batteries using Co₃ HITP₂ as the air cathode catalyst demonstrate excellent energy efficiency and stability.

Keywords: 3d orbital configuration; coordination polymers; flexible electronics; oxygen reduction reaction (ORR); zinc-air battery.

Abstract

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