An Electrochemical Quartz Crystal Microbalance Investigation of Manganese Oxide Deposition and Dissolution in Sulfuric Acid Relevant for Zinc Electrowinning. (10th April 2018)

• Record Type: Journal Article
• Authors: Skaftun, Siri Marie; Sunde, Svein; Haarberg, Geir Martin; Seland, Frode
• Is Part Of: ECS transactions. Volume 85:Number 4(2018)
• Page Start: 103
• Page End: 119
• Publication Date: 2018-04-10
• Subjects: Electrochemistry -- Periodicals; Electrochemistry; Periodicals; Electronic journals; Electronic journal; 541.37
• DOI: 10.1149/08504.0103ecst
• Languages: English
• ISSNs: 1938-5862

Abstract

Abstract : The deposition and dissolution of manganese oxide from a sulfuric acid solution were investigated by conventional electrochemical techniques and EQCM on gold and platinum electrodes. The product of the oxidation was found by EQCM to be MnO2 at a higher potential (1.55 V), whereas a mixture between MnOOH and MnO2 was produced at a lower potential (1.45 V). An ECE mechanism involving the formation of MnOOH was proposed as the oxidation mechanism. A higher deposit porosity was obtained at the higher deposition potentials. The reduction mechanism was proposed to involve an electrochemical reduction of MnO2 to MnOOH, followed by a chemical reaction yielding Mn 2+ and MnO2 .