硫化物在铂电极上电氧化时空动力学的模型模拟和分析.pdf

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1、物理化学学报(WuliHuaxueXuebao1686Acta．-Chim．Sin．2014，30(4)，686-692April[Article】doi：l0．3866／PKU．WHXB201402142www．whxb．pku．edu．cn硫化物在铂电极上电氧化时空动力学的模型模拟和分析杨加平于辉耀何瑜庥解京选毕文彦高庆宇(中国矿业大学化工学院，江苏徐州221l16)摘要：根据铂电极上硫化物电催化氧化的反应机理，本文提取动力学模型并利用数值模拟研究了N型负微分阻抗(N—NDR)振荡区域的电极表面时空反应动力学

2、．在均相体系模拟中观察到电流简单振荡和复杂振荡，其来源于双电层电势自催化与传质限制和毒化物种吸附负反馈的相互耦合．为了更接近于真实体系。在模型中考虑了平行和垂直于电极表面两个方向的传质过程．模拟结果发现了与实验现象具有相同演化行为的复杂斑图，如行波和闪烁波：同时在传质耦合体系模拟中观察到双电层电势双臂螺旋波．本研究工作促进对电化学体系时空斑图的理解和预测．关键词：N型负微分阻抗：振荡与复杂振荡：斑图形成：硫化物电化学氧化：模型模拟中图分类号：0646ModelSimulationandAnalysisofSpat

3、iotemporalDynamicsfortheElectro-OxidationofSulfideonPlatinumYANGJia—PingYUHui—YaoHEYu—XiuXIEJing—XuanBIWen—YanGAOQing—Yu(CollegeofChemicalEngineering,ChinaUniversityofMiningandTechnology,Xuzhou221116,JiangsuProvince,PR．China)Abstract：Basedonthereactionmechani

4、smoftheelectro．oxidationofsulfideonplatinum，weproposeasimplifiedmodelforstudyingthespatiotemporaldynamicsontheelectrodesurfaceintheoscillatoryregionoftheN-shapednegativediferentiaIresistance(N—NDR)throughnumericalsimulation．Simpleandcomplexcurrentoscillations

5、wereobservedduringthehomogeneoussimulation，andthesewerecausedbycouplingbetweenonepositivefeedback，i．e．，double-layerpotentialautocatalysis，andtwonegativefeedbacksconsistingofamass-transportlimitedstepandapoison．adsorptionprocess．Toobtainabettersimulationofthee

6、xperimentalsituation．thetransportofelectroactivespeciesinboththeparallelandverticaldirectionsoftheelectrodewastakenlntoaccounttosimulatepatternformationontheelectrode．Themodelsimulationsgavecomplicatedpatternsincludingtwinkling-eyepatternsandtravelingwaves，wh

7、ichagreequalitativelywiththeexperimentalresultsandpossessthesameevolutionprinciples．Meanwhile，forcertainparametersmorecomplexpatternswereobtained，e．g．，two—armspira1wavesofthedouble-layerpotentia1．Thisopensaninterestingperspectiveintheexplanationandpredictiono

8、fpatternformationinelectrochemicalsystems．KeyWords：N—shapednegativedifferentialresistance；Oscilationandcomplexoscillation；Patternformation；ElectrochemicaIoxidationofsulfide；Modelsimulatio