Immobilization of a Molecular Re Complex on MOF‐derived Hierarchical Porous Carbon for CO2 Electroreduction in Water/Ionic Liquid Electrolyte

• Published in: ChemSusChem Vol. 13; no. 23; pp. 6418 - 6425
• Main Authors: Grammatico, Domenico, Tran, Huan Ngoc, Li, Yun, Pugliese, Silvia, Billon, Laurent, Su, Bao‐Lian, Fontecave, Marc
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 07-12-2020; ChemPubSoc Europe/Wiley
• Subjects: Carbon; Carbon dioxide; Carbon monoxide; catalysis; Catalysts; Chemical Sciences; CO2 electroreduction; Electrolytes; Electrowinning; Formic acid; heterogenization; hierarchical porous carbon; Immobilization; ionic liquid; Ionic liquids; Ions; Material chemistry; Metal-organic frameworks; Polymers; Porous materials; rhenium complex; Selectivity; CO2 electroreduction; rhenium complex; heterogenization; Ionic liquid; hierarchical porous carbon
• ISSN: 1864-5631; 1864-564X
• DOI: 10.1002/cssc.202002014

The development of molecular catalysts for CO2 electroreduction within electrolyzers requests their immobilization on the electrodes. While a variety of methods have been explored for the heterogenization of homogeneous complexes, a novel approach using a hierarchical porous carbon material, derived from a metal–organic framework, is reported as a support for the well‐known molecular catalyst [Re(bpy)(CO)3Cl] (bpy=2,2’‐bipyridine). This cathodic hybrid material, named Re@HPC (HPC=hierarchical porous carbon), has been tested for CO2 electroreduction using a mixture of an ionic liquid (1‐ethyl‐3‐methylimidazolium tetrafluoroborate, EMIM) and water as the electrolyte. Interestingly, it catalyzes the conversion of CO2 into a mixture of carbon monoxide and formic acid, with a selectivity that depends on the applied potential. The present study thus reveals that Re@HPC is a remarkable catalyst, enjoying excellent activity (turnover numbers for CO2 reduction of 7835 after 2 h at −1.95 V vs. Fc/Fc+ with a current density of 6 mA cm−2) and good stability. These results emphasize the advantages of integrating molecular catalysts onto such porous carbon materials for developing novel, stable and efficient, catalysts for CO2 reduction.