title: Electro-deposition and re-oxidation of carbon in carbonate-containing molten salts.
abstract: The electrochemical deposition and re-oxidation of solid carbon were studied in CO3(2-) ion-containing molten salts (e.g. CaCl2-CaCO3-LiCl-KCl and Li2CO3-K2CO3) at temperatures between 500 and 800 °C under Ar, CO2 or N2-CO2 atmospheres. The electrode reactions were investigated by thermodynamic analysis, cyclic voltammetry and chronopotentiometry in a three-electrode cell under various conditions. The findings suggest that the electro-reduction of CO3(2-) is dominated by carbon deposition on all three tested working electrodes (Ni, Pt and mild steel), but partial reduction to CO can also occur. Electro-re-oxidation of the deposited carbon in the same molten salts was investigated for potential applications in, for example, direct carbon fuel cells. A brief energy and cost analysis is given based on results from constant voltage electrolysis in a two-electrode cell.
authors.affiliation: Department of Chemical and Environmental Engineering, and Energy and Sustainability Research Division, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, UK. george.chen@nottingham.ac.uk.
authors.forename: Happiness V
authors.initials: HV
authors.lastname: Ijije
authors.forename: Richard C
authors.initials: RC
authors.lastname: Lawrence
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Siambun
authors.forename: Sang Mun
authors.initials: SM
authors.lastname: Jeong
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Jewell
authors.forename: Di
authors.initials: D
authors.lastname: Hu
authors.forename: George Z
authors.initials: GZ
authors.lastname: Chen