Nickel-Iron-Copper Alloy as Inert Anode for Ternary Molten Carbonate Electrolysis at 650°C. Issue 11 (5th September 2018)

• Record Type: Journal Article
• Authors: Zheng, Kaiyuan; Du, Kaifa; Cheng, Xinhua; Jiang, Rui; Deng, Bowen; Zhu, Hua; Wang, Dihua
• Is Part Of: Journal of the Electrochemical Society. Volume 165:Issue 11(2018)
• Page Start: E572
• Page End: E577
• Publication Date: 2018-09-05
• Subjects: electrolysis -- Inert anode -- molten carbonate; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.1211811jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : The anodic behavior of Ni11Fe10Cu alloy was investigated in molten Li2 CO3 -Na2 CO3 -K2 CO3 at 650° C. A conductive oxide scale consisting of NiO-rich inner layer and LiFeO2 -rich outer layer is formed on the alloy surface after anodic polarization at 0.25V (vs. Ag2 SO4 /Ag reference electrode) for 40 h. Further prolonging the polarization time leads to a three layered film with layered LiFeO2, NiO and Cu, respectively. The octahedral LiFeO2 and NiO in a size of several microns build a dense outermost layer, providing high stability and excellent catalytic activity for oxygen evolution. Behind the layer, NiO and Cu-rich layers contribute enough high electronic conductivity and good adhesion of the scale. The electrode shows a lower onset potential for O2 evolution than Pt and much better catalytic activity for O2 evolution reaction (OER) than SnO2 anode in the melt. To prove the effectiveness of the anode, cobalt powder with high purity was produced using the electrochemically pre-oxidized Ni11Fe10Cu anode in the ternary carbonate eutectic at 650°C.