To monitor the reaction between Ce4+ion and Cl-ion at the electron level,an electrochemical experi-ment was designed in this work.Herein,the intermediate and final products that may be produced during the redox reaction are directly tracked by using cyclic voltammetry,and the influences of Ce4+ion concentration,temperature and F-ion on the reduction peak potential of Ce4+ion were investigated.The results show that Ce4+ion reacts with Cl-ion through an irreversible reaction without any intermediate products,and the rate-determining step of the reaction is diffusion during the electrode reaction.The effects of temperature(20-40℃)and Ce4+ion concentration(0.04-0.12 mol/L)on the reduction peak potential of Ce4+ion can be ignored,but the higher the molar ratio of F-to Ce4+(0-3 mol/mol),the more easily the reduction of Ce4+ion to Ce3+ion occurs.Additionally,the Ce4+ions are preferentially reduced by thiourea when thiourea is added in the HCl solution,and thiourea inhibits the oxidation of Cl-ions to Cl2 by forming a complex with Cl-ions.This work provides a theoretical basis for the role of thiourea in inhibiting Cl2 production and offers a new wav to find new reductants.

School of Metallurgy,Northeastern University,Shenyang 110819,China;National Engineering Research Center for Rare Earth Materials,GRINM Group Co.,Ltd.,Beijing 100088,China;GRIREM Advanced Materials Co.,Ltd.,Beijing 100088,China;General Research Institute for Nonferrous Metals,Beijing 100088,China

[1]Deliang Meng;Xiaowei Huang;Zongyu Feng;Meng Wang;Juanyu Yang;Chao Xia;Yanyan Zhao;Yuqing Wei-.Reaction between tetravalent cerium ion and chloride ion and effect of thiourea using cyclic voltammetry)[J].稀土学报（英文版）,2022(10):1635-1640

Ce4+ion,Ce3+ion,Ce4+ions,wav

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