1 research outputs found
Electrochemical Capture and Release of Carbon Dioxide Using a Disulfide–Thiocarbonate Redox Cycle
We describe a new electrochemical
cycle that enables capture and
release of carbon dioxide. The capture agent is benzylthiolate (RS<sup>–</sup>), generated electrochemically by reduction of benzyldisulfide
(RSSR). Reaction of RS<sup>–</sup> with CO<sub>2</sub> produces
a terminal, sulfur-bound monothiocarbonate, RSCO<sub>2</sub><sup>–</sup>, which acts as the CO<sub>2</sub> carrier species, much the same
as a carbamate serves as the CO<sub>2</sub> carrier for amine-based
capture strategies. Oxidation of the thiocarbonate releases CO<sub>2</sub> and regenerates RSSR. The newly reported <i>S</i>-benzylthiocarbonate (IUPAC name benzylsulfanylformate) is characterized
by <sup>1</sup>H and <sup>13</sup>C NMR, FTIR, and electrochemical
analysis. The capture–release cycle is studied in the ionic
liquid 1-butyl-1-methylpyrrolidinium bisÂ(trifluoroÂmethylÂsulfonyl)Âimide
(BMP TFSI) and dimethylformamide. Quantum chemical calculations give
a binding energy of CO<sub>2</sub> to benzyl thiolate of −66.3
kJ mol<sup>–1</sup>, consistent with the experimental observation
of formation of a stable CO<sub>2</sub> adduct. The data described
here represent the first report of electrochemical behavior of a sulfur-bound
terminal thiocarbonate