title: Efficient and selective molecular catalyst for the CO2-to-CO electrochemical conversion in water.
abstract: Substitution of the four paraphenyl hydrogens of iron tetraphenylporphyrin by trimethylammonio groups provides a water-soluble molecule able to catalyze the electrochemical conversion of carbon dioxide into carbon monoxide. The reaction, performed in pH-neutral water, forms quasi-exclusively carbon monoxide with very little production of hydrogen, despite partial equilibration of CO2 with carbonic acid-a low pKa acid. This selective molecular catalyst is endowed with a good stability and a high turnover frequency. On this basis, prescribed composition of CO-H2 mixtures can be obtained by adjusting the pH of the solution, optionally adding an electroinactive buffer. The development of these strategies will be greatly facilitated by the fact that one operates in water. The same applies for the association of the cathode compartment with a proton-producing anode by means of a suitable separator.
authors.affiliation: Laboratoire d'Electrochimie Moléculaire, Université Paris Diderot, Sorbonne Paris Cité, Unité Mixte de Recherche Université CNRS 7591, 75205 Paris Cedex 13, France.
authors.forename: Cyrille
authors.initials: C
authors.lastname: Costentin
authors.affiliation: Laboratoire d'Electrochimie Moléculaire, Université Paris Diderot, Sorbonne Paris Cité, Unité Mixte de Recherche Université CNRS 7591, 75205 Paris Cedex 13, France robert@univ.paris.diderot.fr saveant@univ-paris-diderot.fr.
authors.forename: Marc
authors.initials: M
authors.lastname: Robert
authors.affiliation: Laboratoire d'Electrochimie Moléculaire, Université Paris Diderot, Sorbonne Paris Cité, Unité Mixte de Recherche Université CNRS 7591, 75205 Paris Cedex 13, France robert@univ.paris.diderot.fr saveant@univ-paris-diderot.fr.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Savéant
authors.affiliation: Laboratoire d'Electrochimie Moléculaire, Université Paris Diderot, Sorbonne Paris Cité, Unité Mixte de Recherche Université CNRS 7591, 75205 Paris Cedex 13, France.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Tatin
keywords: CO2-to-CO conversion; catalysis; contemporary energy challenges; electrochemistry; solar fuels