高等学校化学学报
高等學校化學學報
고등학교화학학보
CHEMICAL JOURNAL OF CHINESE UNIVERSITIES
2014年
12期
2662-2667
,共6页
李梅%李炜%韩伟%张密林%颜永得
李梅%李煒%韓偉%張密林%顏永得
리매%리위%한위%장밀림%안영득
电化学行为%欠电位沉积%恒电位电解%镨-镍金属间化合物
電化學行為%欠電位沉積%恆電位電解%鐠-鎳金屬間化閤物
전화학행위%흠전위침적%항전위전해%보-얼금속간화합물
Electrochemical behavior%Under-potential deposition%Potentiostatic electrolysis%Pr-Ni interme-tallic compound
采用循环伏安、方波伏安、计时电位和开路计时电位等电化学方法研究了Pr (Ⅲ)离子在共晶LiCl-KCl熔盐中Ni电极上的电化学行为及Pr-Ni合金化机理.结果表明, Pr(Ⅲ)离子的电化学还原过程为三电子转移的一步反应.与惰性Mo电极上的循环伏安曲线相比, Pr(Ⅲ)离子在活性Ni电极的循环伏安曲线上还出现了4对氧化还原峰,表明Pr(Ⅲ)离子在Ni电极上发生欠电位沉积,是由于生成不同的Pr-Ni金属间化合物.采用X射线衍射仪和扫描电子显微镜-能谱仪等对恒电位电解的产物进行了表征.结果表明,在不同电位下进行恒电位电解时,每个电位上只得到一种 Pr-Ni 金属间化合物,分别为 PrNi2, PrNi3, Pr2 Ni7和PrNi5.
採用循環伏安、方波伏安、計時電位和開路計時電位等電化學方法研究瞭Pr (Ⅲ)離子在共晶LiCl-KCl鎔鹽中Ni電極上的電化學行為及Pr-Ni閤金化機理.結果錶明, Pr(Ⅲ)離子的電化學還原過程為三電子轉移的一步反應.與惰性Mo電極上的循環伏安麯線相比, Pr(Ⅲ)離子在活性Ni電極的循環伏安麯線上還齣現瞭4對氧化還原峰,錶明Pr(Ⅲ)離子在Ni電極上髮生欠電位沉積,是由于生成不同的Pr-Ni金屬間化閤物.採用X射線衍射儀和掃描電子顯微鏡-能譜儀等對恆電位電解的產物進行瞭錶徵.結果錶明,在不同電位下進行恆電位電解時,每箇電位上隻得到一種 Pr-Ni 金屬間化閤物,分彆為 PrNi2, PrNi3, Pr2 Ni7和PrNi5.
채용순배복안、방파복안、계시전위화개로계시전위등전화학방법연구료Pr (Ⅲ)리자재공정LiCl-KCl용염중Ni전겁상적전화학행위급Pr-Ni합금화궤리.결과표명, Pr(Ⅲ)리자적전화학환원과정위삼전자전이적일보반응.여타성Mo전겁상적순배복안곡선상비, Pr(Ⅲ)리자재활성Ni전겁적순배복안곡선상환출현료4대양화환원봉,표명Pr(Ⅲ)리자재Ni전겁상발생흠전위침적,시유우생성불동적Pr-Ni금속간화합물.채용X사선연사의화소묘전자현미경-능보의등대항전위전해적산물진행료표정.결과표명,재불동전위하진행항전위전해시,매개전위상지득도일충 Pr-Ni 금속간화합물,분별위 PrNi2, PrNi3, Pr2 Ni7화PrNi5.
The electrochemical behavior of Pr (Ⅲ) on a Ni electrode in the LiCl-KCl melt and the alloying mechanism of Pr-Ni alloys were investigated by cyclic voltammetry, square wave voltammetry, chronopoten-tiometry and open-circuit chronopotentiometry. Cyclic voltammetry and square wave voltammetry experiments indicate that the reduction of Pr(Ⅲ) ions into Pr metal occur in a single step with three electrons exchanged. Compared with the cyclic voltammograms on an inert Mo electrode, four reduction peaks are observed, which indicates the under-potential deposition of Pr (Ⅲ) on the reactive Ni electrode due to the formation of Pr-Ni intermetallic compounds. The Pr-Ni alloys obtained by potentiostatic electrolysis were characterized by X-ray diffraction(XRD) and scanning electron micrograph-energy dispersive spectrometry(SEM-EDS). The results show that only one Pr-Ni intermetallic compound, i. e. PrNi2 , PrNi3 , Pr2 Ni7 or PrNi5 , is obtained at each po-tential, respectively. This process can also be used for other electrochemical formation of lanthanide-Ni alloys.