CH(111)CHAROMATIZATIONCH11+4H21CH.CHCHCH2(775)CH2CYCLIZATIONCH-CH33+4H2CH2-CH2PlatinumCatalystCHCH2CH2CH3'CH2'CH2Excess H2CH3HexaneISOMERIZATION(100)CHCH2CH3CH3CH2HYDROGENOLYSISCH2CH3CH2-XCH3CH3CH(10 8 7)Different surfaces do different chemistryStructure-sensitive Catalysis!
(111) (775) (100) (10 8 7) Different surfaces do different chemistry. Structure-sensitive Catalysis!
Anotherexample of Structure-sensitive CatalysisSurface Structure vs. Catalytic Activity2NH3N, + 3HzFeIGOFesinglecrystal(ut)50020 atm/700 K(n'0)100OTEIASSEHINASHN(100)I0S(1O)
418 1 25 Surface Structure vs. Catalytic Activity N2 + 3H2 2NH3 Fe single crystal 20 atm/700 K Another example of Structure-sensitive Catalysis Fe
Role of Structural Chemistryin Material Science
Role of Structural Chemistry in Material Science
C Crystal StructureslentCarboGraphiteDiamondStructuresatomiDiamond:Insulatororwidebandgapsemiconductor: →→→→→→DiamondGraphite:Planar structure:→→→sp2bonding~2dmetal (inplaneSame Element vs. Different StructuresDifferent structure → different properties!OtherCarbonallotropes"Buckyballs" (C60, C7o etc)↓↓“Buckytubes"(nanotubes)otherfullerenes →→→Stable hollow fullerenes: IPRIPR = isolated pentagon rule
Graphite & Diamond Structures Diamond: Insulator or wide bandgap semiconductor: Graphite: Planar structure: sp2 bonding 2d metal (in plane) Other Carbon allotropes “Buckyballs” (C60, C70 etc) “Buckytubes” (nanotubes), other fullerenes C Crystal Structures Same Element vs. Different Structures Different structure different properties! Stable hollow fullerenes: IPR IPR = isolated pentagon rule
Zheng LS（郑兰荪),et allCapturing the labilefullerene[5o]asCsoClioSCIENCE 304 (5671): 699-699 Apr 30, 2004.The pentagon-pentagon fusions in pristine Cso-Dsh are stericallystrainedandhighlyreactivePerchlorination of these active sites stabilizes the labile Cso-Dsh
Zheng LS (郑兰荪), et al. Capturing the labile fullerene[50] as C50Cl10 SCIENCE 304 (5671): 699-699 Apr 30, 2004. • The pentagon-pentagon fusions in pristine C50-D5h are sterically strained and highly reactive. • Perchlorination of these active sites stabilizes the labile C50-D5h