Au@Rhγ-Al2O3纳米催化剂的制备及其反应活性的研究中期报告Abstract:Inthiswork,Au@Rhγ-Al2O3nanocatalystswerepreparedusingco-impregnationmethodandtestedfortheircatalyticactivityintheselectivehydrogenationof4-nitrophenolto4-aminophenol.Theeffectsofvariousparameterssuchasthepreparationmethod,calcinationtemperature,metalloading,andreactionconditionsonthecatalyticperformancewereinvestigated.TheresultsshowedthatthepreparedAu@Rhγ-Al2O3nanocatalystsexhibitedexcellentcatalyticactivityandselectivityforthehydrogenationof4-nitrophenolto4-aminophenol,whichisapromisingcandidateforindustrialapplications.Introduction:Selectivehydrogenationof4-nitrophenolto4-aminophenolisanimportantreactionfortheproductionofvariouschemicals.Theselectivehydrogenationcanbecatalyzedbyvariousmetalcatalysts,includingAu,Pd,Pt,andRh,etc.Amongthesecatalysts,bimetalliccatalystsconsistingofnoblemetalshaveshownsuperiorcatalyticactivityandselectivityduetotheirstrongelectronicinteractionsandsynergisticeffects.Particularly,Au@Rhγ-Al2O3nanocatalystshaveattractedmuchattentionduetotheirstrongsynergisticeffectsandhighstability.Experimental:Au@Rhγ-Al2O3nanocatalystswerepreparedusingco-impregnationmethod.Inatypicalprocedure,γ-Al2O3wasfirstcalcinedat500°Cfor4hourstoremovewaterandimpurities.Then,acertainamountofRhandAuprecursorsweredissolvedindeionizedwaterandimpregnatedontotheγ-Al2O3support.Theimpregnatedsamplesweredriedat110°Cinairfor2hoursandthencalcinedatvarioustemperatures(200-500°C)for4hours.Themetalloadingwascontrolledtobe1wt%foreachmetal.Thecatalyticactivityofthepreparedcatalystswasevaluatedintheselectivehydrogenationof4-nitrophenolto4-aminophenol.Thereactionwascarriedoutusinga50mLreactorunderanitrogenatmosphereandataconstanttemperatureof25°C.Thereactionmixtureconsistedof0.1gcatalyst,10mLwater,and10mL4-nitrophenolsolution(1×10-3M).Thehydrogenationreactionwasinitiatedbyadding50mgNaBH4intothemixture.ResultsandDiscussion:ThepreparedAu@Rhγ-Al2O3nanocatalystswerecharacterizedbyXRD,TEM,XPS,andN2adsorption-desorptionmeasurements.Theresul