Fe(CN)_6^(3-)/Fe(CN)_6^(4-)体系阳极过程的电化学Peltier热  

Electrochemical Peltier heats of anodic process for Fe(CN)_6^(3-)/Fe(CN)_6^(4-)system

作　　者：杨中发[1] 方正[1] 王少芬[2] 张正华[1] 

机构地区：[1]中南大学化学化工学院,湖南长沙410083 [2]长沙理工大学化学与生物工程学院,湖南长沙410077

出　　处：《中南大学学报（自然科学版）》2011年第2期312-316,共5页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(50874119)

摘　　要：采用热电化学方法测定电极反应电化学Peltier热。实验中将高灵敏度热敏电阻紧贴于工作电极表面,结合SRC-100溶解-反应量热仪与电化学工作站组装成高精度热电化学测试系统,其控温精度达±0.001 K。运用该测试系统分别对5个不同浓度等物质的量比的Fe(CN)63-/Fe(CN)64-体系阳极过程进行恒电流极化,得到该电极反应电极电势和温度变化与时间的关系曲线,运用热电化学方程,得到298.15K时Fe(CN)63-/Fe(CN)64-体系阳极过程电化学Peltier热,分别为41.51 kJ/mol(0.075 mol/L),43.48 kJ/mol(0.10 mol/L),46.95 kJ/mol(0.15 mol/L),50.77 kJ/mol(0.20 mol/L)和54.81 kJ/mol(0.25 mol/L),由此获得该温度下的标准氢电极反应在绝对标度下的熵变。The thermo-electrochemical technique was applied to study the electrochemical Peltier heat of electrode reaction.In this experiment,a precision system for thermo-electrochemical measurements with controlled temperature of ±0.001 K was set up,which consists of SRC-100 solution isoperibol calorimeter and an electrochemical workstation.A thermo-sensitive resistor was directly attached to the surface of working electrode to measure the change in potential signal due to temperature change of electrode.The curves of the electrode potential and temperature change against time for equal molar ratio of Fe（CN）63-/Fe（CN）64-couple with 5 sets of different concentrations were obtained under the condition of various constant-current polarizations.Using the thermo-electrochemical method for data-processing,the electrochemical Peltier heat of anodic process of Fe（CN）63-/Fe（CN）64-couple under various concentrations at 298.15 K are determined as 41.51 kJ/mol（0.075 mol/L）,43.48 kJ/mol（0.10 mol/L）,46.95 kJ/mol（0.15 mol/L）,50.77 kJ/mol（0.20 mol/L）and 54.81 kJ/mol（0.25 mol/L）,respectively.The entropy change derived from these Peltier heat for the standard hydrogen electrode on absolute scale at this temperature is also given.

关 键 词：热电化学 Peltier热 标准氢电极 Fe(CN)63-/Fe(CN)64-体系 

分 类 号：O642.3[理学—物理化学] O646[理学—化学]