title: Electrochemical Capture and Release of Carbon Dioxide Using a Disulfide-Thiocarbonate Redox Cycle.
abstract: We describe a new electrochemical cycle that enables capture and release of carbon dioxide. The capture agent is benzylthiolate (RS-), generated electrochemically by reduction of benzyldisulfide (RSSR). Reaction of RS-with CO2produces a terminal, sulfur-bound monothiocarbonate, RSCO2-, which acts as the CO2carrier species, much the same as a carbamate serves as the CO2carrier for amine-based capture strategies. Oxidation of the thiocarbonate releases CO2and regenerates RSSR. The newly reported S-benzylthiocarbonate (IUPAC name benzylsulfanylformate) is characterized by1H and13C NMR, FTIR, and electrochemical analysis. The capture-release cycle is studied in the ionic liquid 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (BMP TFSI) and dimethylformamide. Quantum chemical calculations give a binding energy of CO2to benzyl thiolate of -66.3 kJ mol-1, consistent with the experimental observation of formation of a stable CO2adduct. The data described here represent the first report of electrochemical behavior of a sulfur-bound terminal thiocarbonate.
authors.affiliation: School of Molecular Sciences, Arizona State University , Tempe, Arizona 85281, United States.
authors.forename: Poonam
authors.initials: P
authors.lastname: Singh
authors.affiliation: School of Molecular Sciences, Arizona State University , Tempe, Arizona 85281, United States.
authors.forename: Joseph H
authors.initials: JH
authors.lastname: Rheinhardt
authors.affiliation: Department of Chemistry, University of Washington , Seattle, Washington 98105, United States.
authors.forename: Jarred Z
authors.initials: JZ
authors.lastname: Olson
authors.affiliation: School of Molecular Sciences, Arizona State University , Tempe, Arizona 85281, United States.
authors.forename: Pilarisetty
authors.initials: P
authors.lastname: Tarakeshwar
authors.affiliation: School of Molecular Sciences, Arizona State University , Tempe, Arizona 85281, United States.
authors.forename: Vladimiro
authors.initials: V
authors.lastname: Mujica
authors.affiliation: School of Molecular Sciences, Arizona State University , Tempe, Arizona 85281, United States.
authors.forename: Daniel A
authors.identifier: 0000-0002-6915-6914
authors.initials: DA
authors.lastname: Buttry