简介:Carbon-supportedPdnanoparticleswerepreparedbymicrowaveheating-glycolreductionmethod,andcharacterizedbyawidearrayofexperimentaltechniquesincludingX-raydiffractionspectroscopy(XRD)andtransmissionelectronmicroscopy(TEM).TheelectrooxidationbehaviorsofethanolonthePd/Celectrodeinalkalinemediawereinvestigatedusingcyclicvoltammetry(CV),chronoamperometry(CA),electrochemicalimpedancespectroscopy(EIS)andsinglecellperformancemethods.Pd/Celectrodeforethanoloxidationshowedhighelectro-catalyticactivityandlongtermstability.However,itisobservedthatthecurrentdensitydecreaseswiththeincreasingofthepotentialandnegativeimpedancepresentsinthepotentialfrom-0.1to0.1V.Thedecreasingcurrentdensityandthenegativeimpedancecouldbeduetotheadsorbedintermediatesspeciesthatinhibitedthefurtheroxidationofethanol.BasedonthechemicalreactionanalysisandEISspectra,equivalentcircuitsrelatingtovariouspotentialzoneshavebeenobtained.TheseresultsrevealthedynamicadsorptionofintermediatesspeciesonPdsurfaces.Significantly,itisclarifiedthattheadsorptionbehaviorbeginsfromthemaximumcatalysisofelectro-catalysisandendsintheformationofthepalladium(II)oxidelayerontheelectrodesurface.
简介:目的:1.对现有的CO_2重整系统中铁系催化剂进行改进以期获得更高的产率和产物选择性;2.实现反应体系中催化剂的高效回收以延长反应体系的可持续性。创新点:1.开发复合铁、镍、铜催化剂用于水煤气变换反应,获得了更高的产物选择性;2.提高了CO_2重整体系在常压条件下液态烃类的产率。方法:1.由核心沉淀法制得复合铁/氧化铝催化剂;2.在固定床反应器中进行CO_2重整反应。结论:1.干、湿条件下的CO_2重整过程产生相同数量的CO;当温度高于500°C时,CO的产率达到饱和。2.采用镍作为铁催化剂助剂时,CO的选择性从85%降低到76%,但是产物中可检出9%的甲烷。3.采用铜作为铁催化剂助剂时,尽管CO_2的转化率降低了一半,然而CO的选择性提高到了95%。
简介:本文考察了稀土氧化物,合金和氧化锆对AlPO45载体和Fe/AlPO45催化剂的影响。结果表明,La、Ce和Y稀士氧化物的引入可有效地促进硝酸铁丙酮溶液中制备的Fe/AlPO45催化剂在CO加氢反应中的催化活性;负载不同合金的AlPO45催化剂具有明显不同的催化反应结果;ZrO可调变AlPO5载体的表面性能,削弱活性组份和载体间的相互作用,使在硝酸铁水溶液中制备的催化剂在合成气转化中具有一定的催化活性。更多还原
简介:由于他们的结构上的二金属的nanoparticles(NP)的化学、物理的性质的依赖,他们的结构的特征的基本理解为他们的综合体和宽应用是关键的。在这篇文章,Au-Pd二金属的NP的系统的原子水平的调查被在不同Au/Pd比率和不同尺寸与量修正Sutton陈潜力(Q-SC)使用改进粒子群优化(IPSO)进行。在IPSO,模仿的退火被介绍进古典粒子群优化(PSO)改进有效性和可靠性。另外,结构的稳定性和结构的特征上的起始的结构,粒子尺寸和作文的影响也被学习。模拟结果表明起始的结构在稳定的结构上有小效果,但是极大地影响收敛的率,并且起始的结构清楚地是的混合的集中率快核心壳和阶段比那些组织。我们发现Au-PdNP比较喜欢结构与在外部层Au富有当时在内部的Pd富有。特别,当Au/Pd比率是6:4时,nanoparticle(NP)的结构介绍标准化Pd核心Au壳结构。
简介:1-(2-chlorophenyl)ethanol(CPE)isofhealthandenvironmentalconcernduetoitstoxicityanditsuseasaninter-mediateinpharmaceuticalmanufacturing.ThecurrentworkdealswiththecatalyticreductivedechlorinationanddetoxificationofCPEbyPd/Febimetal.CPEwaseffectivelydechlorinatedto1-phenylethanol(PE)accompaniedbytheequivalentreleaseofchloride.TheextentofCPEdechlorinationincreasedwithtemperature,FedosageandPdloading.AdecreaseinsolutionpHincreasedCPEdechlorination,resultingpresumablyfromanincreaseinhydrogenproduction.Underthespecificconditionsof20g/LPd/Fe,0.10%Pd(w/w)andinitialpH5-6,theCPEdechlorinationwascompletedwithin145min.Thedechlorinationfol-lowedapseudo-first-orderkineticswithanactivationenergyof56.7kJ/mol.TheresultsoftoxicitytestingshowedthatCPEwasverytoxictoChlorella,whereasPEshowedlittletoxicity.Thetoxicityofthereactionsolutiondeclinedgraduallyandthepro-motingeffectsonChlorellaintensifiedconsequentlywiththedechlorinationprocess.Thus,thereductivedechlorinationofCPEtoPEbyPd/Fewasadetoxificationprocess.ItmaybeusedtoeffectivelyreducethetoxicologicaleffectsofCPE-contaminatedwastewater,therebyenhancingtheperformanceofsubsequentbiologicalprocessesinwastewatertreatment.