Electroreduction of CO 2 Catalyzed by a Heterogenized Zn–Porphyrin Complex with a Redox-Innocent Metal Center
- Yale Univ., New Haven, CT (United States). Dept. of Chemistry and Energy Science Inst.
- Oregon State Univ., Corvallis, OR (United States). School of Chemical, Biological, and Environmental Engineering
- Yale Univ., New Haven, CT (United States). Dept. of Chemistry
Transition-metal-based molecular complexes are a class of catalyst materials for electrochemical CO2 reduction to CO that can be rationally designed to deliver high catalytic performance. One common mechanistic feature of these electrocatalysts developed thus far is an electrogenerated reduced metal center associated with catalytic CO2 reduction. Here we report a heterogenized zinc–porphyrin complex (zinc(II) 5,10,15,20-tetramesitylporphyrin) as an electrocatalyst that delivers a turnover frequency as high as 14.4 site–1 s–1 and a Faradaic efficiency as high as 95% for CO2 electroreduction to CO at -1.7 V vs the standard hydrogen electrode in an organic/water mixed electrolyte. While the Zn center is critical to the observed catalysis, in situ and operando X-ray absorption spectroscopic studies reveal that it is redox-innocent throughout the potential range. Cyclic voltammetry indicates that the porphyrin ligand may act as a redox mediator. Chemical reduction of the zinc–porphyrin complex further confirms that the reduction is ligand-based and the reduced species can react with CO2. This represents the first example of a transition-metal complex for CO2 electroreduction catalysis with its metal center being redox-innocent under working conditions.
- Research Organization:
- Yale Univ., New Haven, CT (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences, and Biosciences Division; National Science Foundation (NSF); American Chemical Society Petroleum Research Fund; Institute of International Education (IIE); TomKat Foundation; Argonne National Lab. (ANL), Argonne, IL (United States). Chemical Sciences and Engineering Division and Advanced Photon Source; Dupont Research and Development, Wilmington, DE (United States). DuPont Experimental Station; Northwestern Univ., Evanston, IL (United States); Oregon State Univ., Corvallis, OR (United States); Netherlands Organization for Scientific Research (NWO)
- Grant/Contract Number:
- FG02-07ER15909; CHE-1651717; AC02-06CH11357
- OSTI ID:
- 1372709
- Alternate ID(s):
- OSTI ID: 1423563
- Journal Information:
- ACS Central Science, Vol. 3, Issue 8; ISSN 2374-7943
- Publisher:
- American Chemical Society (ACS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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