Electrolyte Composition‐Dependent Product Selectivity in CO2 Reduction with a Porphyrinic Metal–Organic Framework Catalyst

• Published in: Angewandte Chemie International Edition 2024-11, Vol.63 (45), p.e202411766-n/a
• Main Authors: Pu, Si‐Hua, Huang, Tao, Si, Duan‐Hui, Sun, Meng‐Jiao, Wang, Wen‐Wen, Zhang, Teng, Cao, Rong
• Format: Article
• Language: English
• Subjects: Acetonitrile; Acid production; Carbon dioxide; Catalysts; Catalytic activity; Chemical reduction; Chemical synthesis; CO2 reduction; Composition; electrocatalysis; Electrocatalysts; Electrochemistry; Formic acid; Metal-organic frameworks; metalloporphyrin; metal–organic framework; Porphyrins; Protons
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.202411766

A copper porphyrin‐derived metal–organic framework electrocatalyst, FICN‐8, was synthesized and its catalytic activity for CO2 reduction reaction (CO2RR) was investigated. FICN‐8 selectively catalyzed electrochemical reduction of CO2 to CO in anhydrous acetonitrile electrolyte. However, formic acid became the dominant CO2RR product with the addition of a proton source to the system. Mechanistic studies revealed the change of major reduction pathway upon proton source addition, while catalyst‐bound hydride (*H) species was proposed as the key intermediate for formic acid production. This work highlights the importance of electrolyte composition on CO2RR product selectivity. The major product of electrochemical CO2 reduction on a porphyrinic metal–organic framework catalyst, FICN‐8, was found to switch from CO to formic acid upon electrolyte composition changing. Experimental and theoretical mechanistic studies indicates pathway steering by addition of extra proton source to the electrolyte.