Negative Pressure Pyrolysis Induced Highly Accessible Single Sites Dispersed on 3D Graphene Frameworks for Enhanced Oxygen Reduction

Huang Zhou; Tong Yang; Zongkui Kou; Lei Shen; Yafei Zhao; Zhiyuan Wang; Xiaoqian Wang; Zhenkun Yang; Junyi Du; Jie Xu; Min Chen; Lin Tian; Wenxin Guo; Qiuping Wang; Hongwei Lv; Wenxing Chen; Xun Hong; Jun Luo; Daping He; Yuen Wu

doi:10.1002/anie.202009700

Negative Pressure Pyrolysis Induced Highly Accessible Single Sites Dispersed on 3D Graphene Frameworks for Enhanced Oxygen Reduction

Angew Chem Int Ed Engl. 2020 Nov 9;59(46):20465-20469. doi: 10.1002/anie.202009700. Epub 2020 Sep 4.

Authors

Huang Zhou^{1

2

3}, Tong Yang⁴, Zongkui Kou⁴, Lei Shen⁵, Yafei Zhao¹, Zhiyuan Wang¹, Xiaoqian Wang¹, Zhenkun Yang¹, Junyi Du¹, Jie Xu⁶, Min Chen¹, Lin Tian¹, Wenxin Guo¹, Qiuping Wang¹, Hongwei Lv¹, Wenxing Chen⁷, Xun Hong¹, Jun Luo⁶, Daping He², Yuen Wu^{1

3}

Affiliations

¹ School of Chemistry and Materials Science, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026, China.
² Hubei Engineering Research Center of RF-Microwave Technology and Application, School of Science, Wuhan University of Technology, Wuhan, 430070, China.
³ Dalian National Laboratory for Clean Energy, Dalian, 116023, China.
⁴ Department of Physics, National University of Singapore, Singapore, 117551, Singapore.
⁵ Department of Mechanical Engineering, National University of Singapore, Singapore, 117575, Singapore.
⁶ Laboratory of Advanced Functional Porous Materials, Institute for New Energy Materials & Low-Carbon Technologies, School of Materials Science and Engineering Tianjin University of Technology, Tianjin, 300384, China.
⁷ Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081, China.

PMID: 32715586
DOI: 10.1002/anie.202009700

Abstract

Herein, we report a negative pressure pyrolysis to access dense single metal sites (Co, Fe, Ni etc.) with high accessibility dispersed on three-dimensional (3D) graphene frameworks (GFs), during which the differential pressure between inside and outside of metal-organic frameworks (MOFs) promotes the cleavage of the derived carbon layers and gradual expansion of mesopores. In situ transmission electron microscopy and Brunauer-Emmett-Teller tests reveal that the formed 3D GFs possess an enhanced mesoporosity and external surface area, which greatly favor the mass transport and utilization of metal sites. This contributes to an excellent oxygen reduction reaction (ORR) activity (half-wave potential of 0.901 V vs. RHE). Theoretical calculations verify that selective carbon cleavage near Co centers can efficiently lower the overall ORR theoretical overpotential in comparison with intact atomic configuration.

Keywords: 3D graphene frameworks; metal-organic frameworks; negative pressure; oxygen reduction reaction; single sites.

Abstract

Grants and funding