甲醇在FeS_2(100)完整表面的吸附和分解.pdf

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1、物理化学学报(WuliHuaxueXuebao)MavActaP．一Chim．Sin．2011，27(5)，1075-10801075[Article]www．whxb．pku．edu．C／1甲醇在FeS2(100)完整表面的吸附和分解杜玉栋赵伟娜郭欣章永凡陈文凯1福州大学化学系，福州350108；华中科技大学煤燃烧国家重点实验室，武汉410074)摘要：采用基于第一性原理的密度泛函理论结合周期平板模型方法，研究了甲醇分子在FeSz(1oo)完整表面的吸附与解离．通过比较不同吸附位置的吸附能和构型参数发现：表面Fe位为有

2、利吸附位，甲醇分子通过氧原子吸附在表面Fe位，吸附后甲醇分子中的C—O键和O—H键都有伸长，振动频率发生红移；甲醇分子易于解离成甲氧基CH。O和H，表面Fe位仍然是二者有利吸附位．通过计算得出甲醇在FeSz(1oo)表面解离吸附的可能机理：甲醇分子首先发生。一H键的断裂，生成甲氧基中间体，继而甲氧基C—H键断裂，得到最后产物HCHo和H．关键词：密度泛函理论：甲醇：FeS(1oo)表面：吸附：过渡态中图分类号：O641AdsorptionandDissociationofMethanolonPerfectFeS2(1O0

3、)SurfaceDUYu—Dong’ZHAOWei—Na’GUOXinZHANGYong-Fan’CHENWen—Kai’，(1DepartmentofChemistry,FuzhouUniversFuzhou350108,R．China；。StateKeyLaboratoryofCoalCombustion，HuazhongUniversityofScienceandTechnology,Wuhan410074，PR．China)Abstract：First-principlescalculationsbasedond

4、ensityfunctionaltheory(DFT)andtheperiodicalslabmode1wereusedtostudytheadsorptionanddissociationofmethanoIontheperfectFeS2f10O)surface．TheadsorptionenergyandthegeometricparametersonthedifferentadsorptionsitesshowedthattheFesitewasthemostfavorableadsorptionsiteand0

5、atomswerefoundtobindtoFeatoms．Afteradsorption。theC—OandO—Hbondsofmethano1wereelongatedandthevibrationaIstretchfrequencywasredshifred．Thecalculationresultsprovedthatmethano1waspronetodecompositionresultingjnmethoxygroupsandhydrogen．Wecalculatedtheadsorptionbehavio

6、rofthesemethoxygroupsandhydrogenontheFeS2f100)surfaceandfoundthattheFesiteswerealsothemostfavorableadsorptionsites．Apossibledecompositionpathwaywasinvestigatedusingtransitionstatesearchingmethods：firsttheO—Hbondofmethanolwasdecomposedproducingtheintermediatemetho

7、xygroupandsubsequentIytheC—HbondofthemethoxygroupwasbrokenresultinginfinaIproductsofformaldehydeandhydrogen．KeyWords：Densityfunctionaltheory；Methanol；FeS2(100)surface；Adsorption；Transitionstate1引言过程中具有重要的作用．二硫化亚铁作为地球表面矿物质表面在腐蚀、风化，重金属吸附及催化最丰富的硫矿物之一，其表面活性涉及到废水处Rece

8、ived：December15，20l0：Revised：March6，20l1：PublishedonWeb：March24，20l1．‘Correspondingauthor．Email：qc2008@fzu．edu．cn；Tel：+86—591—22866162．TheprojectWaSsupportedby