Undistorted Cyclic Voltammograms at Scan Rates up to 2.5 MVs~(-1) through Positive Feedback Compensation of Ohmic Drop

Introduction Though being the simplest voltammetric technique, cyclic voltammetry provides lots of electrochemical information especially in the study of the thermody-namic and kinetic processes and the detection of elec-trogenerated transient intermediates.1 Clearly, the more rapid the scan rate is employed, the faster the reactions can be studied. Indeed, a timescale RT/Fν～25 ns of the Faradaic response will be reached corresponding to a scan rateνof 1 MVs-1, which means that the method…     

Exponentially Expanded Grid Network Approach （EEGNA） ： An Efficient Way for the Simulation of Stiff Electrochemical Problems

The exponentially expanded space grid was incorporated into the network approach to overcome the problem of low simulation efficiency during the simulations of electrochemical problems with stiff kinetics or wide dlsperslon of diffusion coefficients, resulting in an effective electrochemical simulation method: exponentially expanded grid network approach (EEG-NA). The stability and accuracy of the EEGNA for the simulation of various electrode processes .coupled with different types of homogeneous reactions were investigated.     

双盘工作电极参比电位采样快扫伏安方法

报道一种双铂盘工作电极、相应的毛细管参比电极和竖直式电化学池设计并用于快速循环伏安测量.双工作电极包括一个常规工作电极,一个辅助工作电极.后者在使用中接地,仅提供参比电位来控制工作电极的电位.参比毛细管尖端安设在接近辅助工作电极的位置上;用0.3mm直径Pt盘工作电极,在电位扫描速度高达10kV/s都可以得到类似于100%iR补偿的伏安曲线,而不必使用iR补偿电路.本文围绕高扫速伏安法中工作电极电位的准确控制问题做了一些初步的探讨.     

指数扩展格网络方法：模拟球、柱和旋转圆盘电极体系电化学问题的有效方法

An exponentially expanded space grid technique has been employed in the network simulation of chronoamperometric and voltammetric problems in spherical, cylindrical and rotating-disk electrode systems, leading to an effective simulation strategy for electrochemical problems: exponentially expanded grid network approach (EEGNA). The success of this method is largely due to the improved ability in processing the boundary singularities existing for non-planar diffusions and the enhanced simulation speed and accuracy in contrast to the uniform or quasi-uniform grid network approach.     

快扫循环伏安曲线的单纯形优化-数值模拟拟合方法

采用Gl算法改进了快扫伏安曲线的数值模拟,提高了模拟计算的速度.使用单纯形优化-数值模拟方法,以电流、峰电位误差的加权值作为拟合参数的评价函数,对二茂铁在0,3mm直径铂盘电极上,不同扫速下的循环伏安图进行了拟合.在拟合过程中自动进行伏安图基线的校正,同时拟合出标准非均相速度常数k~0,未补偿溶液电阻R_u以及双电层电容C_(dl)等重要的参数值,所得k~0值与文献报道结果一致.     

Universal Electrochemical／Chemical Simulator Based on an Exponentially Expanding Grid Network Approach

A universal simulator capable of simulating virtually any user-defined electrochemical/chemical problems in one-dimensional diffusion geometry was developed based on an exponentially expanding grid modification of the existing network approach. Some generalized reaction-diffusion governing equations of an arbitrary electrochemical/chemical process were derived, and program controlled automatic generation of the corresponding PSPICE netlist file was realized. On the basis of the above techniques, a universal simulator package was realized, which is capable of dealing with arbitrarily complex electrochemical/chemical problems with one-dimensional diffusion geometry such as planar diffusion, spherical diffusion, cylindrical diffusion and rotational disk diffusion-convection processes. The building of such a simulator is easy and thus it would be very convenient to have it updated for simulations of newly raised electrochemical problems.     

指数扩展的网络方法模拟超快循环伏安曲线

将指数扩展格原理用于网络模拟方法,给出了模拟受欧姆降歪曲的超快伏安曲线的电路网络模型,利用电路模拟软件ＰＳＰＩＣＥ给出该电路的瞬态响应曲线,并与数值解进行对比,结果表明这一模拟算法准确而稳定,而且计算速度比等格网络法提高１０倍以上。     

快扫循环伏安曲线的单纯形优化—数值模拟合方法

采用Ｇ１算法改进了快扫伏安曲线的数值模拟,提高了模拟计算的速度。使用单纯形优化－数值模拟方法,以电流、峰电位误差的加权值作为拟合参数的评价函数,对二茂铁在０．３ｍｍ直径铂盘电极上,不同扫速下的循环伏安图进行了拟合。在拟合过程中自动进行伏安图基线的校正,同时拟合出标准非均相速度常数ｋ＾０,未补偿溶液电阻Ｒｕ以及又电层电容Ｃｄｌ等重要的参数值,所得ｋ＾０值民文献报道结果一致。     

傅里叶变换用于快扫伏安法的电流分离

根据电化学池的电学模型，推导出相应的数学模型，和傅里变变换相结合，实现了扫描伏安数据的充电电流和法拉第电流的分离。模拟数据和实验数据的处理结果表明，所提出的方法均能实现充电电流和法拉第电流的分离，得到的结果与理论模型一致。     

一种判断电化学/化学反应体系热力学自洽性的新方法

介绍了一种判断电化学/化学反应体系热力学自洽性的新方法-“秩法”。结合 实际例子描述了该方法的原理、计算步骤。该方法充分利用矩阵“秩”的概念,由 反应系数矩阵的“秩”直接判断出其中的独立组分数,并且仅当寻找到依赖反应时 才需对有关方程进行求解。因此,“秩法”概念上清晰、直观,且由于可以直接调 用矩阵变换的子程序,程序实现也极为容易。该方法对于电化学、化学及化工反应 过程的模拟将非常有意义。