Highly efficient electrocatalytic CO2 reduction by a CrIII quaterpyridine complex

• 成果类型: Article
• 署名作者: Wang, Jia- Wei; Luo, Zhi- Mei; Yang, Guangjun; Gil-Sepulcre, Marcos; Kupfer, Stephan; Ruediger, Olaf; Ouyang, Gangfeng
• 署名单位: Sun Yat Sen University; Friedrich Schiller University of Jena; Max Planck Society
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-9556
• DOI: 10.1073/pnas.2319288121
• 发表日期: 2024-04-02
• 关键词: carbon-dioxide; molecular catalysis; activation; porphyrin; epr

摘要

Design tactics and mechanistic studies both remain as fundamental challenges during the exploitations of earth- abundant molecular electrocatalysts for CO2 reduction, especially for the rarely studied Cr-based ones. Herein, a quaterpyridyl Cr-III catalyst is found to be highly active for CO2 electroreduction to CO with 99.8% Faradaic efficiency in DMF/phenol medium. A nearly one order of magnitude higher turnover frequency (86.6 s(-1)) over the documented Cr- based catalysts (<10 s(-1)) can be achieved at an applied overpotential of only 190 mV which is generally 300 mV lower than these precedents. Such a high performance at this low driving force originates from the metal-ligand cooperativity that stabilizes the low- valent intermediates and serves as an efficient electron reservoir. Moreover, a synergy of electrochemistry, spectroelectrochemistry, electron paramagnetic resonance, and quantum chemical calculations allows to characterize the key Cr-II, Cr-I, Cr-0, and CO- bound Cr-0 intermediates as well as to verify the catalytic mechanism.