硫化物在铂电极上电氧化时空动力学的模型模拟和分析(英文)

Model Simulation and Analysis of Spatiotemporal Dynamics for the Electro-Oxidation of Sulfide on Platinum

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.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.

Based on the reaction mechanism of the electro-oxidation of sulfide on platinum, we propose a simplified model for studying the spatiotemporal dynamics on the electrode surface in the oscillatory region of the N-shaped negative differential resistance （N-NDR） through numerical simulation. Simple and complex current oscillations were observed during the homogeneous simulation, and these were caused by coupling between one positive feedback, i.e., double-layer potential autocatalysis, and two negative feedbacks consisting of a mass-transport limited step and a poison-adsorption process. To obtain a better simulation of the experimental situation, the transport of electroactive species in both the parallel and vertical directions of the electrode was taken into account to simulate pattern formation on the electrode. The model simulations gave complicated patterns including twinkling-eye patterns and traveling waves, which agree qualitatively with the experimental results and possess the same evolution principles. Meanwhile, for certain parameters more complex patterns were obtained, e.g., two-arm spiral waves of the double-layer potential. This opens an interesting perspective in the explanation and prediction of pattern formation in electrochemical systems.