铁阳极钝化对高铁酸盐电化合成工艺的影响  

Effect of iron anode passivauion on the electrosynthesis technique of ferrate(VI)

作　　者：何伟春[1] 赵红雨[1] 左宏森[1] 王俊波[2] 

机构地区：[1]河南工业大学材料科学与工程学院,河南郑州450007 [2]浙江大学化学系

出　　处：《无机盐工业》2008年第3期26-29,共4页Inorganic Chemicals Industry

基　　金：河南工业大学博士科研基金资助项目(2007BS045)

摘　　要：使用浓度跟踪分析法和恒电流电解曲线对铁网阳极在浓氢氧化钠溶液中电化合成Fe(VI)工艺及阳极钝化行为进行了研究。结果表明,用Fe(VI)表观电化合成速率、理论电化合成速率和分解速率可以定量描述电解过程中阳极钝化程度,其数学表达式为:θ=1-[r(FeO42-)app-r(FeO42-)d]/r(FeO42-);铁阳极在某种条件下可以明显避免钝化的影响,从而长时间保持较高的Fe(VI)电流效率。具体条件:温度35℃、电流密度≤6.1 mA/cm2和氢氧化钠浓度≥14.5 mol/L。据此可成功电化合成出浓度高于0.78 mol/L高铁酸钠溶液,相应平均电流效率47%。The concentration tracking analysis and constant - current electrolysis curve were adopted to study the process of ferrate （ VI ） electrosynthesis and the behavior of anode passivation in concentrated NaOH solution by using irongrid anode. The results showed that the anode passivation degree during electrolysis can be described quantitatively by using Fe （ VI ）apparent electrosynthesis rate, theory electrosynthesis rate and decomposition rate and the equation is given as ： θ=1-[r（FeO^2-）app-r（FeO^2-）d]/r（FeO^2-） ; It was found that the iron anode passivation can be avoided obviously under some conditions so that the Fe （ VI ） current efficiency will be kept at comparatively high level for a long time. The condition was as follows ： temperature 35 ℃ , current density ≤ 6. 1 mA/cm^2, alkaline concentration ≥ 14.5 mol/L. A solution of NaFeO4 with the concentration over 0.78 mol/L could be electrosynthesized successfully under the above condition and the corresponding mean current efficiency was 47%.

关 键 词：高铁酸盐 阳极钝化 电化合成速率 电解曲线 

分 类 号：TQ138.11[化学工程—无机化工]