au-ag与au-pd复合结构纳米颗粒的制备与其催化应用

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1、ABSTRACTreactionprocess；(iii)severemumaldiffusionofAuandAgatomspromotesalloyformation．TheFourier—transforminfrared(FTIR)spectraofCP肠纱c肠疣extractbeforeandafterreactionindicatedthat(NH)C=Ogroupscanbeadsorbedonthesurfaceofthemetalatomsandberesponsibleforelectronicconductionconduciv

2、efortheformationofAu—Agclusters．Secondly，fourAu-PdbinarymetallicNPshavebeensuccessfullysynthesizedwithhighyieldinasimpleaqueoussystemandtheirstructuresareconfirmedwiththeaidofXRD，EDX，andTEM．Thepreparationofflower-shapedAu—PdalloyNPshasbeendevelopedbasedonsimultaneousreductionof

3、HAuCl4andNa2PdCl4mixturesinthepresenceofCPlatycladiextractandVcatroomtemperature．Theflower—shapedAu．PdalloyNPsadsorbedwithlxl0。8MR6GperformedexcellentSERSenhancementcomparedtothatofsphericalAu-PdNPs，implyingthepotentialapplicationsinoptics．TheAu@Pdnanoflowers(NFs)weresynthesize

4、dbythesuccessive—reductionmethod．InatypicalsynthesisofAu@PdNFs，HAuChwerereducedbyVcfor5minatroomtemperature，thenNazPdCl4wasaddedtothesolutionandC．Platycladiextractweresuccessivelyaddedtothemixtureundervigorousstirringfor25rain．TherearetworepresentativemethodstosynthesizeAu@Pdco

5、re—shellNPs．OneistouseAuNPsasseedsforsubsequentPdgrowthinCPlatycladiextractandwecanobtainAu@Pdnanocubes．WhenmixtureofHAuCl4andNa2PdCl4werekeptat90。Cfor48hinthepresenceofCTAC，Au@Pdnanopolyhedronsshouldbeobtained．WecouldachievenucleationandgrowthofPdonone，three，orsixfacesofanAuna

6、nocubesbysimplycontrollingtherateofPdCl42’atwhichtheprecursorwasintroducedandreduced．Assuch，weobtainedbimetallicnanocrystalswiththreedistinctivestructuresunderotherwisesimilarexperimentalconditions：hybriddimers，eccentricnanobars，andcore—shellNPs．AsforcontrollingtherateofAuCl4‘，

7、similarresultscanbefoundandtheAuatomscouldnucleateandthengrowononeortwopairsofoppositefacesofacubicPdseedotherthanonadjacentfaces．Finally,Au—Pd／MgO，Au@Pd／Ti02andAu—Ag／MgOwerepreparedascatalystsAu—Pd／MgOalloynanocatalystsviasol—immobilization(SI)methodexhibitedIIABSTRACTexcellen

8、tperformanceinliquidphasebenzylalcoholoxidationwith02a