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时间:2020-03-27
《甲酸在Pt—Sn(111)C合金表面吸附的量子化学研究.pdf》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、物理化学学~(WuliHuaxueXuebao12198ActaP.一Chim.Sin.2013,29(1O),2198—2206October[Article]doi:10.3866/PKU.WHXB201307294www.whxb.pku.edu.cn甲酸在Pt—Sn(111)/C合金表面吸附的量子化学研究唐法威郭为民唐楠楠裴俊彦’许旋3,4(广西科技大学生物与化学工程学院,广西柳州545006;成都纺织高等专科学校,成都611731;华南师范大学化学与环境学院,广州510006;华南师范大学,教育部环境理论化学重点实验室,广州510006)摘要:
2、采用周期平板模型,结合密度泛函理论对HCOOH和CO在Pt—Sn(111)/C表面的top、bridge、hcp和fcc共计8个位点的吸附模型进行构型优化和能量计算,并对吸附前后的频率、电荷、能带和态密度进行了研究.计算结果表明fcc.Pt。是较为有利的吸附位点,Sn掺杂之后费米能级右移,导带增宽,价带和导带的位置略微降低,合金表面电子结构变化利于甲酸的吸附解离催化,可使甲酸燃料电池阳极催化性能显著提高.通过催化剂表面的抗中毒分析,发现CO在Pt—Sn(111)/C表面的吸附能以两种趋势下降,阳极催化剂掺杂改性后抗CO中毒能力增强.关键词:直接甲酸燃料电
3、池:Pt—Sn(111)/C表面:密度泛函理论:电子结构:态密度中图分类号:0646QuantumChemicalStudyontheAdsorptionofFormicAcidonaPt-Sn(111)/CAlloySurface1ANGFa.WeiGUOWei—Min’,1。ANGNan—NanPElJun.Yan’XUXuan。-(。CollegeofBiologicalandChemicalEngineering,GuangxiUniversityofScienceandTechonology,Liuzhou54500~GuangxiZhuang
4、AutonomousRegion,PR.China;ChengduTextileCollege,Chengdu611731,PR.China;SchoolofChem~tryandEnvironment,SouthChinaNormal【fGuangzhou51000~R.China;KeyLaboratoryofTheoreticalChem~tryofEnvironment,MinistryofEducation,SouthChinaNormalUniversity,Guangzhou51000~PR.China)Abstract:Densityfu
5、nctionaftheory(DFT)andself-consistentperiodiccalculationswereusedtoinvestigatetheadsorptionofformicacid(HC0OH)andcarbonmonoxide(CO)ateightsites,suchastop。bridge,hcpandfcc,onaPt—Sn(111)tCsurface.Thevibrationalfrequency,electriccharge,energybandanddensityofstatesofHCOOHbeforeandaft
6、eradsorptiononaPt—Sn(1111/Csurfaceweredetermined.Theresultsshowthatbeforedoping,thefavoredadsorptionsiteforHCOOHandCOlsthefcc-Pt3site.AfterdopingthesurfacewithSn,theFerm{IeveImovestotheright,theconductionbandbroadens,andthevalenceandconductionbandsIowerslightly.Thechangeoftheelec
7、tronicstructureonPt.Sn(111)/cpromotesboththeadsorptionanddissociationofHCOOH,whichcanimprovetheperformanceofanodecatalystsfordirectformicacidfueIcellsfDFAFCs).Basedontheanti-poisoninganalysisofthecatalystsurface,itwasalsofoundthattheadsorptionenergYofCOonPt—Sn(111)/Csurfacesislow
8、erthanthatonPt(111)/Cones.Theresultsshow
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