Heterogeneous Molecular Catalysts of Metal Phthalocyanines for Electrochemical CO2 Reduction Reactions

Wu, Yueshen1,2; Liang, Yongye3,4; Wang, Hailiang1,2

2021-08-17

10.1021/acs.accounts.1c00200

ACCOUNTS OF CHEMICAL RESEARCH   影响因子和分区

0001-4842

1520-4898

Molecular catalysts, often deployed in homogeneous conditions, are favorable systems for structure-reactivity correlation studies of electrochemical reactions because of their well-defined active site structures and ease of mechanistic investigation. In pursuit of selective and active electrocatalysts for the CO2 reduction reactions which are promising for converting carbon emissions to useful fuels and chemical products, it is desirable to support molecular catalysts on substrates because heterogeneous catalysts can afford the high current density and operational convenience that practical electrolyzers require. Herein, we share our understanding in the development of heterogenized metal phthalocyanine catalysts for the electrochemical reduction of CO2. From the optimization of preparation methods and material structures for the electrocatalytic activity toward CO2 reduction to CO, we find that molecular-level dispersion of the active material and high electrical conductivity of the support are among the most important factors controlling the activity. The molecular nature of the active site enables mechanism-based optimization. We demonstrate how electron-withdrawing and -donating ligand substituents can be utilized to modify the redox property of the molecule and improve its catalytic activity and stability. Adjusting these factors further allows us to achieve electrochemical reduction of CO2 to methanol with appreciable activity, which has not been attainable by conventional molecular catalysts. The six-electron reduction process goes through CO as the key intermediate. Rapid and continuous electron delivery to the active site favors further reduction of CO to methanol. We also point out that, in homogeneous electrocatalysis where the catalyst molecules are dissolved in the electrolyte solution, even if the molecular structure remains intact, the actual catalysis may be dominated by molecules permanently adsorbed on the electrode surface and is thus heterogeneous in nature. This account uses our research on CO2 electroreduction reactions catalyzed by metal phthalocyanine molecules to illustrate our understanding about heterogeneous molecular electrocatalysis, which is also applicable to other electrochemical systems.

SCI

英语

其他

U.S. National Science Foundation[CHE-1651717] ; National Science Foundation of China[22075125] ; Guangdong Provincial Key Laboratory[2018B030322001]

Chemistry

Chemistry, Multidisciplinary

WOS:000687058900003

AMER CHEMICAL SOC

CHEMISTRY

Web of Science

1.Yale Univ, Dept Chem, New Haven, CT 06520 USA
2.Yale Univ, Energy Sci Inst, West Haven, CT 06516 USA
3.Southern Univ Sci & Technol, Dept Mat Sci & Engn, Shenzhen 518055, Peoples R China
4.Southern Univ Sci & Technol, Guangdong Prov Key Lab Energy Mat Elect Power, Shenzhen 518055, Peoples R China

Wu, Yueshen,Liang, Yongye,Wang, Hailiang. Heterogeneous Molecular Catalysts of Metal Phthalocyanines for Electrochemical CO2 Reduction Reactions[J]. ACCOUNTS OF CHEMICAL RESEARCH,2021,54(16).

Wu, Yueshen,Liang, Yongye,&Wang, Hailiang.(2021).Heterogeneous Molecular Catalysts of Metal Phthalocyanines for Electrochemical CO2 Reduction Reactions.ACCOUNTS OF CHEMICAL RESEARCH,54(16).

Wu, Yueshen,et al."Heterogeneous Molecular Catalysts of Metal Phthalocyanines for Electrochemical CO2 Reduction Reactions".ACCOUNTS OF CHEMICAL RESEARCH 54.16(2021).