摘要
用循环伏安和交流阻抗等方法详细研究了SiW11O39Fe(Ⅲ)(H2O)5-(SiW11Fe)的电化学性质和对H2O2还原的间接电催化作用,并与PW11O39Fe(Ⅲ)(H2O)4-(PW11Fe)进行了比较,同时提出了电催化反应的机理。实验结果表明,与PW11Fe类似,SiW11Fe在酸性水溶液中也有3对还原氧化伏安响应,分别归属于Fe(Ⅲ)/Fe(Ⅱ)电对和W-O骨架的还原氧化反应。但SiW11Fe的3对还原氧化波的峰电位与PW11Fe相比明显负移,且均受溶液pH的影响。SiW11Fe中Fe(Ⅲ)/Fe(Ⅱ)电对传递电子的可逆性比PW11Fe的差,但同样对H2O2的还原具有明显的电催化作用,并受溶液pH的影响。随着溶液pH的增加,Fe波和W-O骨架波的还原氧化峰电位均负移,Fe波对H2O2还原的电催化活性降低甚至被完全抑制,相反,第一个W-O骨架波对H2O2的还原却有明显的电催化作用。
Electrochemical properties of SiW11O39Fe（Ⅲ）（H2O）5-（SiW11Fe） and its electrocatalysis for H2O2 reduction in a solution of 0.1 mol·L-1 NaHSO4 ＋ Na2SO4 were investigated in detail using the electrochemical methods such as cyclic voltammetry and AC impedance etc.At the same time,a comparison with PW11O39Fe（Ⅲ）（H2O）4-（PW11Fe） was made and an indirect electrocatalysis mechanism was proposed.Experimental results indicated that SiW11Fe possesses three pairs of redox waves attributed to the voltammetric responses of the Fe（Ⅲ）/Fe（Ⅱ） redox couple and the W-O skeleton,respectively,similar to PW11Fe.Compared with PW11Fe,all peak potentials of the three pairs of redox waves moved obviously to negative direction for SiW11Fe and were affected by the solution pH.The Fe（Ⅲ）/Fe（Ⅱ） redox couple of SiW11Fe has a worse reversibility of electron transfer than that of PW11Fe,but similarly exhibit a high electrocatalytic activity for H2O2 reduction,which was affected by the solution pH.With increasing of the solution pH,the redox peak potentials of the Fe wave and W-O waves shifted negatively;the electrocatalytic activity of the Fe wave towards H2O2 reduction declined or even was completely inhibited.Instead,the first W-O skeleton wave showed a distinct electrocatalysis for H2O2 reduction.
出处
《中山大学学报（自然科学版）》
CAS
CSCD
北大核心
2012年第3期73-78,共6页
Acta Scientiarum Naturalium Universitatis Sunyatseni
基金
国家自然科学基金资助项目(20963003
21161007)
海南省重点科技资助项目(090803)
吉林省科技发展计划资助项目(20090595)
国家大学生创新资助项目(101165811
101165821)
海南师范大学开放实验室资助项目(kfsy11005)
