工业催化原理-英文课件chapter22old.ppt

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1、§2.2CatalysisbytransitionmetalcomplexesCatalysisbytransitionmetalcomplexeshasbeenwidelyusedinchemicalreactionssuchaspolymerization,oxidation,isomerization,hydroxylation,carbonylation…2.2.1OrganometalliccomplexesOrganometalliccomplexusedascatalystisgenerallycomposedofametalatomorionin

2、thecenterwithseveralatomsorgroupsofatomscalledligands（配体）bondedaroundtoformapolyhedron.§2.2.1OrganometalliccomplexesGeneralgeometryofcomplexOctahedralcomplexwithsixsurroundingligands,hybridizationschemed2sp3Tetragonalpyramidalcomplexwithfiveligandsanddsp3hybridizationTetrahedralorsqu

3、areplanarcomplexwithfourligands,hybridizationschemeissp3anddsp2respectively.§2.2.1OrganometalliccomplexesTransitionmetal:Pd,Pt,Ni,Co,Fe,Rh,Ru...钯、铂、镍、钴、铁、铑、钌...Ligand:NH3,CO,Cl-,C2H4...Thecatalyticactionofcomplexesusuallyresultsfromtheinteractionofligandsincoordinationspherewiththece

4、ntralmetaltochangetheirchemicalbondingactivation.ComplexofPt2+andethylene-complexing§2.2.2SamplesofcomplexcatalyzedreactionCatalyzedhydrogenationofethyleneCatalyticcomplex:squareplanarstructureRh+Cl(PPh3),triphenylphasphinePossiblemechanism:complexRh+ClL3dissociationunsaturatedc

5、oordinatecomplexoxide-additivereactionwithhydrogenRh3+ClL2H2octahedralcomplexcomplexingwithethylenedesorptionofethane.MechanismofhydrogenationofethyleneAdvantageofthemetalcomplexcatalystsIngeneral,moleculesofcomplexcatalystiswelldispersedinthesolventsothatitusuallyhasveryhighacti

6、vity.Thecentralmetalionandthesurroundingligandscanbewidelyselected,especiallypartoforalltheligandscanbespeciallychangedtomatchthecriticalrequestsofthereaction,leadinghighproductselectivity§2.2.2SampleswithindustrialsignificancePreparationofaldehydefromethyleneoxidation,Wackerreaction

7、.C2H4+½O2CH3CHOcatalyst:Pd2+Cl4planarcomplexPropenepolymizationwithZiegler-Nattacatalyst:TiCl3–Al(C2H5)2MethanolcarbonylationCH3OH+COCH3COOHcatalyst:Rh(CO)2I2§2.2.2SampleswithindustrialsignificanceMethanolcarbonylationCH3OH+COCH3COOHoldcatalyst:Co2(CO)8at475-600atmand210-250Cgivi

8、ngayieldofab