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Title: Electroreduction of CO 2 Catalyzed by a Heterogenized Zn–Porphyrin Complex with a Redox-Innocent Metal Center

Transition-metal-based molecular complexes are a class of catalyst materials for electrochemical CO 2 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 CO 2 reduction. Here in this paper, 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 CO 2 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 CO 2. This represents the first example of a transition-metal complex for CO 2 electroreduction catalysis with its metal center being redox-innocent under working conditions.
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  1. Yale Univ., New Haven, CT (United States). Dept. of Chemistry; Yale Univ., West Haven, CT (United States). Energy Sciences Inst.
  2. Yale Univ., New Haven, CT (United States). Dept. of Chemistry; Yale Univ., West Haven, CT (United States). Energy Sciences Inst.
  3. Oregon State Univ., Corvallis, OR (United States). School of Chemical, Biological, and Environmental Engineering
  4. Yale Univ., New Haven, CT (United States). Dept. of Chemistry
Publication Date:
Grant/Contract Number:
FG02-07ER15909; AC02-06CH11357; CHE-1651717
Published Article
Journal Name:
ACS Central Science
Additional Journal Information:
Journal Volume: 3; Journal Issue: 8; Journal ID: ISSN 2374-7943
American Chemical Society (ACS)
Research Org:
Yale Univ., New Haven, CT (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Chemical Sciences, Geosciences & 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)
Country of Publication:
United States
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1421363; OSTI ID: 1423563