Prof. Genqiang Zhang, Prof. Jing Xia, and Angew's viewpoint: The use of rapid reconstitution-induced defective bismuth for CO2 formic acid production
【Article Information】
Rapid reconstitution-induced defective bismuth was used for electrocatalytic CO2 formic acid production
First author: Wang Xiaowen, Zhang Yangyang, Wang Shao
Corresponding authors: Prof. Genqiang Zhang, Prof. Jing Xia
Affiliation: University of Science and Technology of China, Institute of Physics and Chemistry, Chinese Academy of Sciences
【Background】
Electrocatalytic CO2 reduction technology (ECO2RR) is an effective strategy to solve environmental and energy problems at this stage due to its mild reaction conditions, easy assembly and operation, and also helps to mitigate the greenhouse effect and store intermittent clean electricity provided by solar and wind energy. According to the recent technical and economic analysis, among the many reduction products, formic acid is the liquid product with the most economic benefits and commercial value, and also has a wide range of applications in industrial fields such as hydrogen storage, fuel cells, textiles, and drug synthesis. At present, bismuth-based catalysts have attracted extensive attention in the electrochemical conversion of CO2 to formic acid due to their advantages of environmental friendliness, abundant reserves, and strong adsorption capacity for key intermediates *OCHO.
However, most bismuth-based catalysts undergo electrochemical reconstitution at negative potential, which complicates the identification of their active sites and catalytic mechanisms. In addition, the coordination environment of the precursor has a significant impact on the electrochemical reconstitution process, the exposure of the active crystal plane and the final form of the catalyst. Therefore, it is particularly important to study the electrochemical reconstruction of catalysts and understand the formation mechanism of actual catalytic active sites for the accurate design of efficient and stable electrocatalysts.
【Introduction】
Recently, Professor Zhang Genqiang from the University of Science and Technology of China and Professor Xia Jing from the Institute of Physics and Chemistry of the Chinese Academy of Sciences published a research article entitled "Steering Geometric Reconstruction of Bismuth with Accelerated Dynamics for CO2 Electroreduction" in the internationally renowned journal Angew. In this paper, a defective bismuth nanosheet catalyst with high catalytic performance (V-Bi NS) was introduced, and the causes of the formation of defective bismuth and the influence of precursor coordination environment on the electrochemical reconstruction rate were explored through a combination of theory and experiment, and the principle of improving the electrocatalytic performance of the defect site was deeply analyzed.
Figure 1. Structural analysis and reconstitution mechanism of Bi19Cl3S27 precursor.
图2. Bi19Cl3S27前驱体和V-Bi NS催化剂的形态和结构表征。
Figure 3. Experimental verification of precursor reconstruction speed and in-situ infrared detection intermediates.
图4. V-Bi NS和I-Bi NS的电催化性能。
Figure 5. Density functional theory (DFT) calculations for V-Bi and I-Bi models
【Main points of the text】
Point 1: An in-depth interpretation of chlorine-induced vacancies-rich defective bismuth nanosheets.
In this work, the electrochemical reconstruction process of Bi19Cl3S27 and Bi2S3 was studied, and it was found that Bi19Cl3S27 had a faster reconstitution rate, which led to the rapid explosion of nucleation and growth of bismuth metal to form bismuth nanosheets rich in vacancy defects. Bi2S3 undergoes slow reconstitution to form intact bismuth crystals. Theoretical analysis shows that the Cl of Bi19Cl3S2 attracts the electrons of Bismuth due to high electronegativity, resulting in the formation of charge-polarized bismuth bits. This promotes the rapid transport of electrons and the rapid collapse of the Bi19Cl3S27 structure during the reconstitution, and promotes the metallization process of trivalent bismuth.
Point 2: Highly active atomic vacancy defects contribute to the ECO2RR performance of catalysts.
In-situ infrared observation showed that compared with I-Bi NS, V-Bi NS had a more significant adsorption effect on *OCHO and CO2. DFT calculations show that the bismuth vacancy is in an electron-rich aggregation state, which reduces the activation energy of CO2 to *CO2- radicals and the speed-determining step energy barrier of formic acid formation, and effectively improves the conversion efficiency of CO2 to formic acid.
Point 3: Excellent electrocatalytic performance.
In the wide current density range of -50 to -300 mA cm-2, the FE of formic acid exceeds 95%, and the catalytic performance of V-Bi NS is much higher than that of I-Bi NS. Its ECSA normalized formic acid current density and yield are also 2.2 times higher than that of I-Bi NS, and it is stable for 30 hours at a current density of -200 mA cm-2.
【Article Link】
“Steering Geometric Reconstruction of Bismuth with Accelerated Dynamics for CO2 Electroreduction” Angew. Chem. Int. Ed. 2024, e202407665.
https://doi.org/10.1002/anie.202407665
【About the Corresponding Author】
Genqiang Zhang: Professor of University of Science and Technology of China, Doctoral Supervisor, Dual-employed Researcher of Hefei Microscale National Scientific Research Center, National Overseas High-level Talent, Elsevier China Highly Cited Researcher, Member of Advanced Ceramics Branch of Chinese Materials Science Society, Young Editorial Board Member of eScience, Infomat, SusMat and Nano Research. The research group is committed to the optimal synthesis of advanced functional nanomaterials and their application in energy devices, including the application of electrode materials for energy storage devices, the design and synthesis of high-performance electrocatalysts, and the application of novel composite nanostructures in the field of energy storage and conversion. To date, in Nat. Commun.、Sci. Adv.、Adv. Mater.、Angew. Chem. Inter. Ed and other internationally renowned academic journals have published more than 140 SCI research papers, with more than 11,000 citations and an H-factor of 55.