电化学选择性氢化脱氯反应.ppt

银 钯催化的电化学选择性氢化脱氯反应 浙江工业大学 化学工程学院绿色化学合成技术国家重点实验室培育基地 徐颖华 马红星 丁旭芬 马淳安 Silver Palladium electrocatalyzedselectivehydrodechlorination 1 目录 1 银 钯催化的电化学选择性氢化脱氯反应简介 2 多氯吡啶甲酸的电化学选择性氢化脱氯反应 3 其他多氯有机物的电化学选择性氢化脱氯反应 4 总结和展望 ZhejiangUniversityofTechnology 2 1 银 钯催化的电化学选择性氢化脱氯反应简介 有机合成 合成部分氯代有机物作为药物中间体或原料药 要求 区域选择性脱氯 1 1 主要用途及要求 ZhejiangUniversityofTechnology RondininiS etal ElectroreductionofHalogenatedOrganicCompounds 2010 279 AlonaoF etal Chem Rev 2002 102 11 4009 4091 环境保护 降解环境中存在的高毒 难降解氯代有机物 要求 化学选择性脱氯 3 1 2 催化原理 IsseA A etal J Phys Chem C 2009 113 14983 WangA etal J Am Chem Soc 2010 132 9534 DaboP etal Environ Sci Technol 2000 34 1265 ChenG etal J Phys Chem B 2006 110 4863 Fig 1 1Thehydrodechlorinationmechanismonsilverelectrode Fig 1 2Thehydrodechlorinationmechanismonpalladiumelectrode 4 2 多氯吡啶甲酸的电化学选择性氢化脱氯 化工学报 2010 61 699 ZhejiangUniversityofTechnology 5 Fig 2 1CVsof3 5 6 T a atfourelectrodesinaN2 saturated0 25MPBSatpH 3 b ataAg r electrodeinaN2 saturated0 5MH2SO4 pH 0 2 a0 5MNaOH pH 13 3 aqueoussolution and0 25MPBSofthreedifferentpHvalues 3 7 and11 scanratev 50mVs 1 T 297K Electrochim Acta 2015 151 284 ZL201410264884 1 ZhejiangUniversityofTechnology 2 1 银催化 pH 3 Ag r 6 Table2 1Electrochemicalreductionof3 33mM3 5 6 TinaN2 saturated0 5MH2SO4 pH 0 2 a0 5MNaOH pH 13 3 aqueoussolution and0 25MPBSofthreedifferentpHvalues 3 7 and11 at297Konfivecathodes a2F mol 1of3 5 6 Twereconsumedintheall10electrolysisexperiments bCurrentefficiencycalculatedwithrespecttotheproduced3 5 D c3 5 Dand3 6 Dselectivitycalculatedwithrespecttotheconverted3 5 6 T ZhejiangUniversityofTechnology 7 Fig 2 2Productselectivityandcarbonmassbalanceduringtheelectrochemicalreductionof42 5mM3 5 6 Tat297K Catholye 30mL0 25MPBSatpH 3 Cathode Ag r meshelectrodes 2 5cm 3cm ZhejiangUniversityofTechnology 8 ZhejiangUniversityofTechnology Fig 2 3EffectsofpHontheselectivityforhydrodechlorinationofTeCPonsilvercathodes 9 Fig 2 5LSVofNifoam Agmesh Cufoamelectrodes andPd Nifoam Pd Agmesh Pd Cufoamelectrodesina0 5MNaOHaqueoussolution v 5mV s withtwoconcentrationsof3 6 D Temperature 25 Fig 2 4SEMofNiandPd Nifoam AgandPd Agmesh CuandPd Cufoam ZL201510401434 7 ZL201510401039 9 ZhejiangUniversityofTechnology 2 2 钯催化 Pd Nifoam Nifoam Agmesh Cufoam Pd Agmesh Pd Cufoam 10 Table2 2EffectofelectrolytecompositionontheECHdechlorinationof0 25M3 6 D a aCathode aPd Nifoam Projectedarea 2 6cm2 Pdloading 2 25mg cm2 cCEwascalculatedwith t 6h d3 6 Dwasaddedintothecatholyteinadividedfashionduringthefirsthourofelectrolysisduetoitspoorsolubility ZhejiangUniversityofTechnology 11 Fig 2 6EffectofpHonproductselectivityandCEduringtheECHdechlorinationof3 6 D Cathode aPd Nifoam Catholyte AandA 50mL1 25MNaOH 96mM3 6 D andB B 50mL0 75MH2SO4 96mM3 6 D 20 v vEthanol CEwascalculatedwith t 1 2 3 4 5or6 0h ZhejiangUniversityofTechnology 12 Scheme1ProposedmechanismsfortheECHdechlorinationof3 6 D ZhejiangUniversityofTechnology 13 Fig 2 7EffectsofcathodecatalystsandpHontheselectivityforhydrodechlorinationofTeCP ZhejiangUniversityofTechnology 14 3 其他多氯有机物电化学选择性氢化脱氯 3 1 三氯甲基苯 Fig 3 1CVof5 0mMbenzenyltrichlorideandbenzylchloride inCH3CN 0 1mMTBAPonAgelectrode 2mm at298K v 100mVs 1 T 20 物理化学学报 2013 29 973 ZhejiangUniversityofTechnology Agelectrode Agelectrode 15 Table3 1ElectroreductionofbenzenyltrichlorideatAgmesh 2 5 3 0cm2 in40mLcatholyte CH3CN 0 1mMTBAP 5 0mMbenzenyltrichloride at20 aAppliedpotentialvs Ag Ag bInpresentof1MCH3COOH ZhejiangUniversityofTechnology 16 3 2 氯乙酸 Fig 3 2CVsofthreeelectrodesinblank0 5MNaOH 1 blue 2 3 red andinpresentof50mMTCAA 1 black redandgreen or50mMMCAA 2 3 black v 50mVs 1 T 298K J Electroan Chem 2012 664 39 ZhejiangUniversityofTechnology CCl3COOH TCAA CH2ClCOOH MCAA Ag p Ag r 17 Fig 3 3CVsofAg r electrodeinblankaqueoussolutions 1 0 05MTCAA 2 0 05MDCAA 3 0 05MMCAA 4 nothing at50mVs 1 ZhejiangUniversityofTechnology 1 CCl3COOH TCAA 2 CHCl2COOH DCAA 3 CH2ClCOOH MCAA 4 blank pH 2 2 pH 7 18 Fig 3 4ThereductionofTCAA 0 05M usingAg r electrode at298K inaqueoussolutionsof 1 0 5MH2SO4 2 0 5MNa2SO4and 3 0 5MNaOH Fig 3 5Currentefficiencyforthereductionof0 05MTCAA usingAg r electrode 2cm 3cm 0 1cm usingappliedcurrent110mA 1 0 5MH2SO4 2 0 5MNa2SO4and 3 0 5MNaOH ZhejiangUniversityofTechnology 19 Fig 3 6SEM 1 Ag p electrode 2 Pd Ag p electrode 3 Ag r electrode and 4 Pd Agelectrode 3 3 2 4 二氯苯氧乙酸 Electrochem Commun 2009 11 2133 Electrochim Acta 2013 96 90 ZhejiangUniversityofTechnology Ag p electrode Ag r electrode Pd Ag p electrode Pd Ag r electrode 20 Fig 3 7CVsoffiveelectrodesinblank0 5MNaOH a b c d black f black andinpresenceof25mM2 4 D d red green e f red 50mVs 1 ZhejiangUniversityofTechnology 21 Table3 2Electroreductionsof25mM2 4 Din0 5MNaOH onfourdifferentelectrodes 3 4cm2 PAA phenoxyaceticacid ClPAA 2 Cland4 Cl phenoxyaceticacid 2 4 D 2 4 diCl phenoxyaceticacid ZhejiangUniversityofTechnology 22 ZhejiangUniversityofTechnology Fig 3 8TheproductselectivityandcarbonmassbalanceduringtheECHdechlorinationof2 4 D Fig 3 9ThehydrodechlorinationmechanismonPd Ag r electrode 23 4 总结和展望 ZhejiangUniversityofTechnology 通过改变催化剂类型和电解液pH 很多氯代有机物氢化脱氯反应的选择性有望得到有效控制 银催化剂适合需要控制区域选择性的氢化脱氯反应 钯催化