乙酰基二茂铁在圆盘电极上的电化学行为及扩散系数的测定  

Electrochemical Behaviors of Acetylferrocene at Disk Electrode and Measurement of Diffusion Coefficient

作　　者：朱崇秀[1] 乔庆东[1] 李琪[1] 宋之林[1] 

机构地区：[1]辽宁石油化工大学石油化工学院,辽宁抚顺113001

出　　处：《辽宁石油化工大学学报》2014年第1期12-15,共4页Journal of Liaoning Petrochemical University

基　　金：辽宁省教育厅科技攻关项目(L2011057)

摘　　要：利用循环伏安法研究了在0.2mol/L的LiClO4溶液中,乙酰基二茂铁(AFc)在圆盘电极(RDE)上的电化学行为,采用两种方法求得乙酰基二茂铁的扩散系数:一种是利用静止圆盘电极测定扩散系数,另一种是用旋转圆盘电极测定扩散系数。实验结果表明:乙酰基二茂铁在圆盘电极上的氧化还原反应为扩散控制的可逆过程,氧化还原峰电位差ΔEp≈56.5mV,电子转移数n=1。通过测定静止圆盘电极的电流-电位曲线,得到AFc的扩散系数Da=4.74×10-5 cm2/s,AFc+的扩散系数Dc=4.47×10-5 cm2/s。而通过测定旋转圆盘电极上的峰电流与电位扫描速率关系曲线,得到的AFc的扩散系数Da=5.20×10-5 cm2/s,AFc+的扩散系数Dc=5.07×10-5 cm2/s,比静止圆盘电极测定扩散系数略高。同时测定电极反应的还原过程的速率常数kfc=7.17×10-3 cm2/s,氧化过程的速率常数kfa=8.31×10-3 cm2/s。The electrochemical behaviors of acetylferrocene at a disk electrode in 0 .2mol/L LiClO4 solution had been determined by using cyclic voltammetry .Two methods were used to determine the diffusion coefficient of acetylferrocene ,in which the rotating disk electrode was motionless and rotational respectively .Electrochemistry experimental results show that the electrochemical process of acetylferrocene at the rotating disk electrode belongs to reversible redox reaction which was controlled by the diffusion . The peak - peak potential ΔEp and the number of transfer electron n were 56 .5 mV and 1 respectively .The diffusion coefficient of AFc and AFc＋ were 4 .74 × 10 -5 cm^2/s and 4 .47 × 10^-5 cm^2/s determined by the current-voltage curve in static disk electrode .And the diffusion coefficient of AFc and AFc＋ were 5 .20 × 10^-5 cm^2/s and 5 .07 × 10^-5 cm^2/s according to the relationship of the peak current and the scan rate in rotating disk electrode ,which was little faster than that of in static disk electrode .Rate constants of reduction process and oxidation process were 7 .17 × 10^-3 cm^2/s and 8 .31 × 10 -3 cm^2/s ,respectively .

关 键 词：乙酰基二茂铁 静止圆盘电极 旋转圆盘电极 电化学行为 扩散系数 

分 类 号：TE662[石油与天然气工程—油气加工工程] O657.81[理学—分析化学]