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Regulating the Coordination Environment of MOF-Templated Single-Atom Nickel Electrocatalysts for Boosting CO2 Reduction |
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| Authors: | Dr Yun-Nan Gong Dr Long Jiao Yunyang Qian Prof?Dr Chun-Yang Pan Dr Lirong Zheng Dr Xuechao Cai Prof?Dr Bo Liu Prof?Dr Shu-Hong Yu Prof?Dr Hai-Long Jiang |
| Institution: | 1. Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Soft Matter Chemistry, Collaborative Innovation Center of Suzhou Nano Science and Technology, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026 P. R. China;2. Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Soft Matter Chemistry, Collaborative Innovation Center of Suzhou Nano Science and Technology, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026 P. R. China
These authors contributed equally to this work.;3. School of Light Industry and Chemical Engineering, Guangdong University of Technology, Guangzhou, 510006 P. R. China;4. Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049 P. R. China;5. Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Soft Matter Chemistry, Collaborative Innovation Center of Suzhou Nano Science and Technology, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026 P. R. China College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou, 450001 P. R. China |
| Abstract: | The general synthesis and control of the coordination environment of single-atom catalysts (SACs) remains a great challenge. Herein, a general host–guest cooperative protection strategy has been developed to construct SACs by introducing polypyrrole (PPy) into a bimetallic metal–organic framework. As an example, the introduction of Mg2+ in MgNi-MOF-74 extends the distance between adjacent Ni atoms; the PPy guests serve as N source to stabilize the isolated Ni atoms during pyrolysis. As a result, a series of single-atom Ni catalysts (named NiSA-Nx-C) with different N coordination numbers have been fabricated by controlling the pyrolysis temperature. Significantly, the NiSA-N2-C catalyst, with the lowest N coordination number, achieves high CO Faradaic efficiency (98 %) and turnover frequency (1622 h?1), far superior to those of NiSA-N3-C and NiSA-N4-C, in electrocatalytic CO2 reduction. Theoretical calculations reveal that the low N coordination number of single-atom Ni sites in NiSA-N2-C is favorable to the formation of COOH* intermediate and thus accounts for its superior activity. |
| Keywords: | CO2-Elektroreduktion Koordinationsumgebung Metall-organische Gerüste Einzelatomkatalysatoren |