title: A local proton source enhances CO2 electroreduction to CO by a molecular Fe catalyst.
abstract: Electrochemical conversion of carbon dioxide (CO(2)) to carbon monoxide (CO) is a potentially useful step in the desirable transformation of the greenhouse gas to fuels and commodity chemicals. We have found that modification of iron tetraphenylporphyrin through the introduction of phenolic groups in all ortho and ortho' positions of the phenyl groups considerably speeds up catalysis of this reaction by the electrogenerated iron(0) complex. The catalyst, which uses one of the most earth-abundant metals, manifests a CO faradaic yield above 90% through 50 million turnovers over 4 hours of electrolysis at low overpotential (0.465 volt), with no observed degradation. The basis for the enhanced activity appears to be the high local concentration of protons associated with the phenolic hydroxyl substituents.
authors.affiliation: Université Paris Diderot, Sorbonne Paris Cité, Laboratoire d'Electrochimie Moléculaire, Unité Mixte de Recherche Université-CNRS no. 7591, Bâtiment Lavoisier, 15 Rue Jean de Baïf, 75205 Paris Cedex 13, France. cyrille.costentin@univ-paris-diderot.fr
authors.forename: Cyrille
authors.initials: C
authors.lastname: Costentin
authors.forename: Samuel
authors.initials: S
authors.lastname: Drouet
authors.forename: Marc
authors.initials: M
authors.lastname: Robert
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Savéant
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry*; D002248:Carbon Monoxide / Q000737:chemistry*; D002384:Catalysis; D055664:Electrochemical Techniques; D007501:Iron / Q000737:chemistry*; D008665:Metalloporphyrins / Q000737:chemistry*; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry; D011522:Protons
chemical_list: D008665:Metalloporphyrins; D010636:Phenols; D011522:Protons; D002245:Carbon Dioxide; C032547:iron tetraphenylporphyrin; D002248:Carbon Monoxide; D007501:Iron