英语翻译Redox potentials and kinetics of the Ce3+/Ce4+ redox rea

英语翻译
Redox potentials and kinetics of the Ce3+/Ce4+ redox reaction and solubility of cerium sulfates in sulfuric acid solutions
Abstract
Experimental work was performed with the aim of evaluating the Ce4+/Ce3+ redox couple in sulfuric acid electrolyte for use in redox flow battery (RFB) technology.The solubility of cerium sulfates in 0.1–4.0 M sulfuric acid at 20–60 °C was studied.A synergistic effect of both sulfuric acid concentration and temperature on the solubility of cerous sulfate was observed.The solubility of cerous sulfate significantly decreased with rising concentration of sulfuric acid and rising temperature,while the solubility of ceric sulfate goes through a significant maximum at 40 °C.Redox potentials and the kinetics of the cerous/ceric redox reaction were also studied under the same temperature–concentration conditions.The redox potentials were measured using the combined redox electrode (Pt–Ag/AgCl) in equimolar Ce4+/Ce3+ solutions (i.e.[Ce3+]=[Ce4+]) in sulfuric acid electrolyte.The Ce3+/Ce4+ redox potentials significantly decrease (i.e.shift to more negative values) with rising sulfuric acid concentration; a small maximum is observed at 40 °C.Cyclic voltammetric experiments confirmed slow electrochemical kinetics of the Ce3+/Ce4+ redox reaction on carbon glassy electrodes (CGEs) in sulfuric acid solutions.The observed dependencies of solubilities,the redox potentials and the kinetics of Ce3+/Ce4+ redox reaction on sulfuric acid concentration are thought to be the result of inequivalent complexation of the two redox species by sulfate anions:the ceric ion is much more strongly bound to sulfate than is the cerous ion.The best temperature–concentration conditions for the RFB electrolytes appear to be 40 °C and 1 M sulfuric acid,where the relatively good solubility of both cerium species,the maximum of redox potentials,and the more or less satisfying stability of CGE s were found.Even so,the relatively low solubility of cerium salts in sulfuric acid media and slow redox kinetics of the Ce3+/Ce4+ redox reaction at carbon indicate that the Ce3+/Ce4+ may not be well suited for use in RFB technology.
Keywords
Redox flow battery; Sulfuric acid; Cerous and Ceric sulfate; Solubility; Cyclic voltammetry; Carbon glassy electrode; Redox potential

氧化还原电位和Ce3 +的/价铈氧化还原硫酸铈在硫酸溶液中的反应和溶解性动力学
摘要
实验工作是用评估价铈+ / Ce3 +的氧化还原电对在硫酸电解液在氧化还原液流电池（ RFB ）技术使用的目的进行的.铈硫酸盐在0.1-4.0 M硫酸在20-60 ℃时的溶解度进行了研究.观察两者的硫酸浓度和温度对硫酸铈的溶解性的协同效应.硫酸铈的溶解度用硫酸和温度上升的上升浓度显著降低,而硫酸铈中的溶解度会经过一个显著最高在40℃下氧化还原电势和酸铈/二氧化铈的氧化还原反应的动力学相同温度浓度条件下也进行了研究.氧化还原电位,用合成的氧化还原电极（ Pt-Ag/AgCl ）等摩尔价铈/ Ce3 +的硫酸电解质溶液（即[ Ce3 +的] = [价铈] ）测得.该Ce3 +的/ Ce4 +离子的氧化还原电位显著降低（即移位到更负的值）与上升的硫酸浓度;小最大值在40℃下观察到的循环伏安实验证实了Ce3 +的/价铈氧化还原对玻碳电极在硫酸溶液反应（ CGES ）的慢电化学动力学.溶解度,氧化还原电位和硫酸浓度Ce3 +的/ Ce4 +离子的氧化还原反应的动力学的观察依赖关系被认为是两个氧化还原物质由硫酸根阴离子的不等价络合的结果是：高铈离子被更强烈地结合到硫酸比的就是铈离子.最佳温度浓度条件,为RFB电解质似乎是40°C和1M硫酸,其中两个铈物种的相对良好的溶解性,被发现的最大氧化还原电位的,和CGE S中的更多或更少的令人满意的稳定性.即使如此,铈盐在硫酸介质和Ce3 +的/ Ce4 +离子的氧化还原在碳反应的缓慢氧化还原动力学的溶解度相对低表明Ce3 +的/ Ce4 +离子可能不会非常适合于在RFB技术的使用.
关键词
氧化还原液流电池;硫酸;铈和硫酸高铈;溶解度;循环伏安法;碳玻电极;氧化还原电位