Electrochemistry of MoO3–K2MoO4 melts: a chance to control the nature of reduced molybdenum oxides

Autor: Eduard E. Levin, Sergey Yu. Vassiliev, Alexander Yu. Filatov, Galina A. Tsirlina, Veronika K. Laurinavichyute
Rok vydání: 2012
Předmět:
Zdroj: Journal of Solid State Electrochemistry. 16:3515-3528
ISSN: 1433-0768
1432-8488
Popis: Cathodic electrodeposition of oxides on platinum from MoO3–K2MoO4 (3.85–75 mol% MoO3) under DC and pulsed galvanostatic modes is discussed in combination with voltammetry data. Characteristic potential values (as related to oxygen evolution onset) are reported for Mo(VI/IV) redox processes, as well as for electrochemical equilibria with participation of molybdenum metal and Pt–Mo alloys. On the basis of scan rate effects and results for various potential limits, and also of voltammetry with preliminary potentiostatic accumulation of products, molybdate reduction mechanism complicated by a chemical step of Mo metal oxidation is proposed. This qualitative assumption is verified in preparative electrolysis experiments with products identification by means of X-ray diffractometry, scanning electron microscopy, and EDX local analysis. Deposition under pulsed mode is found to be useful tool to adjust the duration of chemical step and by these means to alter the composition of final products. The conditions supporting the formation of MoO2 and more reduced oxides are formulated.
Databáze: OpenAIRE
Externí odkaz: