二氧化硅电脱氧反应的交流阻抗谱-JournalofNortheasternUniversity.PDF

第28 卷第4期 东 北 大 学 学 报 ( 自 然 科 学 版 ) Vol28, No. 4 2007 年 4 月 Journal of Northeastern U niversity( Natural cience) Apr. 2 0 07 王淑兰, 张 华, 庄立军 ( , 110004) : iO CaCl NaCl 2 2 , iO , 2 XRD , : iO, Ca iO Ca iO 3 2 4 , iO , 2 , iO 2 iO 2 : ; ; ; : TF 803. 27 : A : 1005-3026( 2007) 04-0537-04 AC Impedance Spectrum of Electro- deoxidation Reaction of Silicon Dioxide WAN G Shu-lan, ZHAN G H ua, ZH UAN G L i-j un ( chool of ciences, Northeastern University , henyang 110004, China, Correspondent: WANG hu-lan, professor, E-mail: shulanw @ hotmail. com) Abstract: AC impedance spectrum w as used to study the electro-deoxidation reaction of silicon dioxide in the equalmolar molten salt CaCl and NaCl. The AC impedance spectra showed that the 2 electro-deoxidation reaction of silicon dioxide is a tw o-step reaction and corresponding to the tw o reduction current peaks in the cyclic voltammetry curve. In the XRD pattern the intermediates iO, Ca iO3 and Ca2 iO4 w ere found in the reaction system . By fitting the AC impedance spectra w ith equivalent circuits, the charge transfer resistance, double layer capacitance and activation energy during the reaction w ere obtained. In the low voltage range the charge transfer resistance and activation energy decrease w ith increasing cathodic voltage w hich implies that charge transfer is the rate contro