Anodic Gases Generated on a Carbon Electrode in Oxide-Ion Containing Molten CaCl2 for the Electro-Deoxidation Process. Issue 14 (1st January 2018)

• Record Type: Journal Article
• Authors: Xie, Hongwei; Zhao, Haijia; Song, Qiushi; Ning, Zhiqiang; Qu, Jiakang; Yin, Huayi
• Is Part Of: Journal of the Electrochemical Society. Volume 165:Issue 14(2018)
• Page Start: E759
• Page End: E762
• Publication Date: 2018-01-01
• Subjects: Electroanalytical Electrochemistry -- Electrochemical Engineering -- Molten Salts - High temperature molten salts -- carbon anode -- electrolysis -- molten CaCl2; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0251814jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : The gas generated on a commonly used carbon anode is highly related to the efficiency of electrolysis and the purity of cathodic products in molten CaCl2 . Herein, the anodic gas generated on a carbon working electrode in a three-electrode setup was systematically analyzed using a gas chromatograph under controlled potentials in both molten CaCl2 and CaCl2 -1 wt%CaO. Two successive oxidation steps of the graphite electrode were observed. The anodic gas contains both CO and CO2 with an atomic ratio (CO/CO2 ) of 0.076, 0.072, 0.073, and 0.144 under anodic potentials of 0V, 0.2V, 0.4V, and 0.6V (vs . Ag/AgCl) in molten CaCl2, respectively, while the atomic ratios of CO/CO2 are 3.639, 2.008, 1.666, 0.720 in molten CaCl2 -1 wt%CaO. Therefore, CaO remarkably enhances the kinetics of the formation of CO and absorption of the generated CO2 forming CO3 2− that could decrease the efficiency of the electrolysis and purity of cathodic products.