کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
192927 459756 2008 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Investigation on electrochemical reduction process of Nb2O5 powder in molten CaCl2 with metallic cavity electrode
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Investigation on electrochemical reduction process of Nb2O5 powder in molten CaCl2 with metallic cavity electrode
چکیده انگلیسی

The direct electrochemical reduction process of Nb2O5 powder was investigated by cyclic voltammetry and constant potential electrolysis with a novel metallic cavity electrode in molten calcium chloride at 850 °C. The products of both constant potential and constant voltage electrolysis were characterized by XRD, SEM and EDX. CaNb2O6 was formed upon addition of solid Nb2O5 into molten CaCl2 when CaO was present. During the electrolysis solid Nb2O5 was reduced to various niobium oxides of lower oxidation states, including some composite oxides, and then was converted completely to metallic niobium near −0.35 V (vs. Ag/AgCl), which was more positive than the reduction potential of Ca2+. Constant potential electrolysis was applied at the potentials near the reduction current peaks derived from the cyclic voltammetry curves, and cell voltages were monitored. The voltage was near 2.4 V when the oxide was metallized at −0.35 V (vs. Ag/AgCl). Nb2O5 pellet could be used to prepared metallic niobium at cell voltage 2.4 V in a larger electrolysis bath filled with calcium chloride at 850 °C. The experiment results further demonstrated the direct electrochemical reduction mechanism of Nb2O5 powder in a molten system.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Electrochimica Acta - Volume 53, Issue 12, 1 May 2008, Pages 4074–4081
نویسندگان
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