Mechanistic Elucidations of Highly Dispersed Metalloporphyrin Metal-Organic Framework Catalysts for CO2 Electroreduction

Michael R. Smith, Clare B. Martin, Sonia Arumuganainar, Ari Gilman, Bruce E. Koel, Michele L. Sarazen

Research output: Contribution to journalArticlepeer-review

16 Scopus citations

Abstract

Immobilization of porphyrin complexes into crystalline metal–organic frameworks (MOFs) enables high exposure of porphyrin active sites for CO2 electroreduction. Herein, well-dispersed iron-porphyrin-based MOF (PCN-222(Fe)) on carbon-based electrodes revealed optimal turnover frequencies for CO2 electroreduction to CO at 1 wt.% catalyst loading, beyond which the intrinsic catalyst activity declined due to CO2 mass transport limitations. In situ Raman suggested that PCN-222(Fe) maintained its structure under electrochemical bias, permitting mechanistic investigations. These revealed a stepwise electron transfer-proton transfer mechanism for CO2 electroreduction on PCN-222(Fe) electrodes, which followed a shift from a rate-limiting electron transfer to CO2 mass transfer as the potential increased from −0.6 V to −1.0 V vs. RHE. Our results demonstrate how intrinsic catalytic investigations and in situ spectroscopy are needed to elucidate CO2 electroreduction mechanisms on PCN-222(Fe) MOFs.

Original languageEnglish (US)
Article numbere202218208
JournalAngewandte Chemie - International Edition
Volume62
Issue number8
DOIs
StatePublished - Feb 13 2023

All Science Journal Classification (ASJC) codes

  • General Chemistry
  • Catalysis

Keywords

  • Electrocatalysis
  • Immobilization
  • Metal–Organic Framework
  • Reaction Mechanism
  • Spectroscopy

Fingerprint

Dive into the research topics of 'Mechanistic Elucidations of Highly Dispersed Metalloporphyrin Metal-Organic Framework Catalysts for CO2 Electroreduction'. Together they form a unique fingerprint.

Cite this