Pd modified electrodes possess problems such as easy agglomeration and low electrolytic ability,and the use of manganese dioxide(MnO2)to facilitate Pd reduction of organic pollutants is just started.However,there is still a limited understanding of how to match the Pd load and MnO2 to realize optimal dechlo-rination efficiency at minimum cost.Here,a Pd/MnO2/Ni foam cathode was successfully fabricated and applied for the efficient electrochemical dechlorination of 2,4,6-trichlorophenol(2,4,6-TCP).The optimal electrocatalytic hydrodechlorination(ECH)performance with 2,4,6-TCP dechlorination efficiency(92.58％in 180 min)was obtained when the concentration of PdCl2 precipitation was 1 mmol/L,the deposition time of MnO2 was 300 s and cathode potential was-0.8 V.Performance influenced by the exogenous fac-tors(e.g.,initial pH and coexisted ions)were further investigated.It was found that the neutral pH was the most favorable for ECH and a reduction in dechlorination efficiency(6％～47.6％)was observed in pres-ence of 5 mmol/L of NO2-,NO3-,S2-or SO32-.Cyclic voltammetry(CV)and quenching experiments verified the existence of three hydrogen species on Pd surface,including adsorbed atomic hydrogen(H*ads),ab-sorbed atomic hydrogen(H*abs),and molecular hydrogen(H2).And the introduction of MnO2 promoted the generation of atomic H*.Only adsorbed atomic hydrogen(H*ads)was confirmed that it truly facili-tated the ECH process.Besides H*ads induced reduction,the direct reduction by cathode electrons also participated in the 2,4,6-TCP dechlorination process.Pd/MnO2/Ni foam cathode shows excellent dechlo-rination performance,fine stability and recyclable potential,which provides strategies for the effective degradation of persistent halogenated organic pollutants in groundwater.

Zi-Meng Zhang;Rui Cheng;Jun Nan;Xue-Qi Chen;Cong Huang;Di Cao;Cai-Hua Bai;Jing-Long Han;Bin Liang;Zhi-Ling Li;Ai-Jie Wang

State Key Laboratory of Urban Water Resource and Environment,School of Environment,Harbin Institute of Technology,Harbin 150090,China;National Technology Innovation Center of Synthetic Biology,Tianjin Institute of Industrial Biotechnology,Chinese Academy of Sciences,Tianjin 300308,China;State Key Laboratory of Urban Water Resource and Environment,School of Civil&Environmental Engineering,Harbin Institute of Technology Shenzhen,Shenzhen 518055,China

中国化学快报（英文版）

[1]Zi-Meng Zhang;Rui Cheng;Jun Nan;Xue-Qi Chen;Cong Huang;Di Cao;Cai-Hua Bai;Jing-Long Han;Bin Liang;Zhi-Ling Li;Ai-Jie Wang-.Effective electrocatalytic hydrodechlorination of 2,4,6-trichlorophenol by a novel Pd/MnO2/Ni foam cathode)[J].中国化学快报（英文版）,2022(08):3823-3828

hydrodechlorination,trichlorophenol,dechlo,rination

Effective,electrocatalytic,by,novel,MnO2,foam,cathode,modified,electrodes,possess,problems,such,easy,agglomeration,low,electrolytic,use,manganese,dioxide,facilitate,reduction,organic,pollutants,just,started,However,there,still,limited,understanding,match,load,realize,optimal,efficiency,minimum,cost,Here,was,successfully,fabricated,applied,efficient,electrochemical,TCP,ECH,performance,obtained,when,concentration,PdCl2,precipitation,deposition,potential,Performance,influenced,exogenous,tors,initial,coexisted,ions,were,further,investigated,It,found,that,neutral,most,favorable,observed,pres,NO2,NO3,S2,SO32,Cyclic,voltammetry,CV,quenching,experiments,verified,existence,three,hydrogen,species,surface,including,adsorbed,atomic,abs,molecular,H2,And,introduction,promoted,generation,Only,confirmed,truly,tated,process,Besides,induced,direct,electrons,also,participated,shows,excellent,fine,stability,recyclable,which,provides,strategies,effective,degradation,persistent,halogenated,groundwater

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