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1、NO2在Ag_Pt(110)双金属表面上的吸附和分解April[Article]物理化学学报(WuliHuaxueXuebao)ActaPhys.-Chim.Sin.2013,29(4),837-842doi:10.3866/PKU.WHXB201301241837www.whxb.pku.edu.cnNO2在Ag/Pt(110)双金属表面上的吸附和分解李金兵1(1中国石化北京北化院燕山分院,北京102500;2姜志全2,*黄伟新2,*中国科学技术大学化学物理系,合肥微尺度物质科学国家实验室(筹),中国科学院能量转换材料重点实验室,合肥230026)摘要:利用俄歇
2、电子能谱(AES)和程序升温脱附谱(TDS)研究了NO2在Ag/Pt(110)双金属表面的吸附和分解.室温下NO2在Ag/Pt(110)双金属表面发生解离吸附,生成NO(ads)和O(ads)表面吸附物种.在升温过程中NO(ads)物种发生脱附或者进一步分解.500K时NO2在Ag/Pt(110)双金属表面发生解离吸附生成O(ads)表面吸附物种.Pt向Ag传递电子,从而削弱Pt-O键的强度,降低O(ads)从Pt表面的并合脱附温度.发现能够形成具有稳定组成的Ag/Pt(110)合金结构,其表现出与Pt(110)-(1×2)相似的解离吸附NO2能力,但与O(ads
3、)的结合明显弱于Pt(110)-(1×2).该AgPt(110)合金结构是可能的低温催化直接分解氮氧化物活性结构.关键词:Ag/Pt(110)双金属表面;中图分类号:二氧化氮;化学吸附;分解;助剂作用O643AdsorptionandDecompositionofNO2onAg/Pt(110)BimetallicSurfaceLIJin-Bing1JIANGZhi-Quan2,*HUANGWei-Xin2,*(1YanshanBranchofSINOPECBeijingResearchInstituteofChemicalIndustry,SINOPEC,Beij
4、ing102500,P.R.China;2HefeiNationalLaboratoryforPhysicalSciencesattheMicroscale,ChineseAcademyofSciences,KeyLaboratoryofMaterialsforEnergyConversion,DepartmentofChemicalPhysics,UniversityofScienceandTechnologyofChina,Hefei230026,P.R.China)Abstract:TheadsorptionanddecompositionofNO2onAg
5、/Pt(110)bimetallicsurfaceshavebeeninvestigatedbyAugerelectronspectroscopy(AES)andthermaldesorptionspectroscopy(TDS).Atroomtemperature,NO2undergoesdissociativechemisorptiononAg/Pt(110)bimetallicsurfaces,formingchemisorbedNO(ads)andO(ads).Uponheating,NO(ads)undergoesbothdesorptionfromth
6、esurfaceandfurtherdecomposition.At500K,NO2chemisorbsdissociativelyonAg/Pt(110)bimetallicsurfaces,formingO(ads).ElectrontransferoccursfromPttoAg,therefore,thepresenceofAgonPt(110)surfaceweakensthebindingenergyofO(ads)withthesurfaceanddecreasesthetemperaturerequiredfortherecombinativede
7、sorptionofO(ads)fromthesurface.WeobservedtheformationofaAg/Pt(110)alloystructurethatexhibitscatalyticactivitytowardsNO2decompositionsimilartothatofPt(110)-(1×2)butwithabindingenergytowardsO(ads)muchlowerthanthatofPt(110)-(1×2).SuchaAg/Pt(110)alloystructuremaybeactiveincatalyzingthedir
8、ectde