硫化物电化学氧化过程研究

用电化学方法研究了碱性溶液中硫化物在Pt电极上的氧化过程。结果表明，硫离子在－600－＋750mV(vs.SCE）存在两个电化学氧化过程。经热力学、动力学和化学分析证实，在约－400mV时硫离子首先氧化为单质硫及多硫化物，沉积在电极表面；约250mV处，单质硫及多硫化物进一步氧化为硫酸根离子而进入溶液，低电位下的氧化反应是可逆反应，硫离子扩散为控制步骤；高电位下，单质硫进一步氧化为硫酸根离子的反应是不可逆反应，而两反应过程密切相关。

Electrochemical Oxidization of Sulfide in Alkaline Solution

Electrochemical oxidization of sulfide on platinum in alkaline solution has been studied by using electrochemical techniques.Results indicate that the two oxidizations of sulfide exist in the range from － 600 mV to ＋ 750 mV(vs.SCE).From the point of view of thermodynamics,chemical analysis and kinetics,at － 400 mV the sulfide is first oxidized to sulphur and polysulfides deposited on the electrode,and at 250 mV sulphur is further oxidized to sulfate entering solution.Oxidization under lower potential is a reversible reaction and the rate-determining step of this reaction is sulfide ions-diffusion controlling.The reaction that sulphur is further oxidized to sulfate under higher potential is an irreversible reaction.These two processes are closely correlated with each other.