Recently, Huang Yanqiang, a researcher at the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, and Zhang Tao, a deputy dean of the Chinese Academy of Sciences, and the academician of the Chinese Academy of Sciences Zhang Tao teamed up with Liu Bin, a professor at the Nanyang Technological University of Singapore to develop a nitrogen-doped graphene-anchored Ni monocatalyst that can be used as a catalyst. High-efficiency electrocatalysts for carbon dioxide reduction. Relevant research results are published in Nature-Energy in the form of co-corresponding authors.
Carbon dioxide electrochemical reduction is an effective way to achieve recycling of carbon resources. Design excellent catalysts to reduce overpotential, improve reaction selectivity and stability is CO 2The focus of the electrochemical reduction research is that the structure of the active site of the monoatomic catalyst is clear, and the electronic structure of the central metal depends on the interaction between adjacent coordination atoms and can exhibit properties similar to those of homogeneous catalysts, which in turn promises to achieve CO 2The efficient activation and directional transformation of molecules. Therefore, monoatomic catalysts in CO 2Electrochemical reduction shows great potential.
In this study, a Ni-doped graphene-anchored Ni monoatomic catalyst was prepared by pyrolysis of a mixture of nitrogen, carbon organics, and Ni salts at various temperatures. Using a variety of characterization methods, Ni was coordinated with four pyridine nitrogens. A Ni-N4 structure is formed, in which Ni is +1 valence and the outermost electronic structure is 3d9; the 3d unpaired electrons of the outermost layer of the Ni(I) single atom are easily delocalized, enabling some electrons to pass from Ni3dx2 -y2 orbital delocalization, with adsorbed CO 2The 2p orbital of the molecule forms a covalent bond, eventually forming a negatively charged Ni-CO 2Δ-structure, thus achieving CO 2The efficient activation of molecules. Ni monoatomic catalysts in CO 2Electrochemical reduction exhibited excellent catalytic performance: at a potential of 0.6 V overvoltage, to a specific current of 350 amps per gram and a switching frequency of 14800 h-1, the CO conversion has a 97% Faraday efficiency. At a current density of 22 mA· After 100 hours of continuous reaction at cm-2, the catalyst retained 98% of its initial activity. Related research results are highly efficient CO 2The design of electroreduction catalysts provides new ideas.
The study was supported by the National Key Research and Development Program, the Strategic Leading Science and Technology Project of the Chinese Academy of Sciences, and the Collaborative Innovation Center for Energy Materials Chemistry of the Ministry of Education.
