如何设计催化剂

1、1Harold H. KungChemical Engineering DepartmentNorthwestern UniversityEvanston, IL 60208-3120October 13, 20032What would one like to accomplish in total catalyst synthesis? Shape of the cavity Path to cavity Ability to design and position ancillary groups Complete atomic control of active site (metal

2、, oxide)3Metal Crystallite Catalytic Active Phase Surface arrangement of atoms Composition Nature of support Location of crystallite on support (defect sites) Structure sensitivity Electronic effect Ligand effect 4Metal clusters derived from metal carbonyl complexesBC Gates J. Molec. Catal. A Chem 1

3、63 (2000) 55Os5C on MgOIr4 in zeolite5Size-selective cluster beam deposition of Aun clusters on MgOHeiz, Sanchez, Abbet, Schneider, Chem. Phys. 262 (2000) 189.MS signal of C16O18O in TPD after exposure to 18O2 and then CO6Aaron S. Eppler, Gnther Rupprechter, Lszl Guczi, and Gabor A. Somorjai, J. Phy

4、s. Chem. B 101 (1997) 9973.Array of Pt on silicaDeposition of metal clusters using lithographyInsufficient control of shape, exact size, and atom locations; current limit on smallest size achieved.7P-SO32- + Mn+(aq) P-SO32-Mn+P-SO32-Mn+ + NaBH4 P-SO32-/MoPreparation of uniform sized metal particles

5、using functional resinsCorain, Centomo, Ferrari Meyer-Zaika, Schmid, Gold2003, October 2003.8Control of surface coordinative unsaturation sites of aluminum oxide (Al2O3) by synthesis Active sites are surface exposed Al ions (Lewis acid sites).AlOAlOOAlOOOActive siteAlOAlOOAlOOOHigh temp-H2OAlOHOHOO(

6、HO)3Al(HO)3AlnAlOHOHHOHOOHOHOAlAlOOO-H2OAlOAlOOAlOOOAlOAlOOAlOOAlOOAlOOOHigh temp-H2OAlOHOHOO(HO)3Al(HO)3AlAlAlOHOHOO(HO)3Al(HO)3AlnAlOHOHHOHOnAlOHOHHOHOAlAlOHOHHOHOOHOHOAlAlOOOOHOHOAlAlOOOAlAlOOO-H2O-H2O9AlAlORORROROROORNRH2H2OOH2RNAlAlOOOH2RNStrategy: use amine (Lewis base) to preserve Lewis acidi

7、ty.AlORNRH2RORO2monomerCan make monomerAmine protection is retainedFinal solid an active catalystKozlov, Kung, Xue, and Kung, Angew. Chem. Int. Ed. 42(2003) 241510051015202530050010001500Time (min)Conversion of epoxide (%)Conversion of cyclopentene oxide in reaction with piperidine catalyzed by vari

8、ous aluminas. PPD-Al2O3, SG-Al2O3-200, SG-Al2O3-500-H2O-200, SG-Al2O3-500-H2O, PA-Al2O3-500-H2O-200 PA-Al2O3-500-H2O, blank. O+HNOHNOH77oCO+HNOHNOHOHNOH77oCXue, Kung, Kozlov, Popp, and Kung, Catal. Today, 2003.11Generation of active site by building on a well-defined structure12131415001203cJ.M. Tho

9、mas, et al. Nature 398 (1999) 227; Angew. Chem. Int. Ed. 39 (2000) 2310.ReactantConv.1-ol1-ald 1-acid 1,6-acid 1,6-ol/al 2-ol/oneCoAlPO-18 (Co/P=0.04)C6H147.2%4.53.353.536.1CoAlPO-18 (Co/P=0.1)9.3%42.43331.61.924.5CoAlPO-36 (Co/P=0.04)5.2%8.73.810.229CoAlPO-34 (Co/P=0.1)7.9%7.36.229.419.73.930.91.5

10、MPa air, 373 K, 24 h, Selectivity %Hexane ( ) Oxidation Two Co(III) ions in CoAlPO-18 at the desired distance apart in Co/P = 0.1 samples. CoAlPO-36 of larger pore structure and shape, produces much more 3-ol and 3-one.Importance in controlling relative location of sitesRaja and Thomas, J. Molec. Ca

11、tal. 181 (2002) 316-120-100-80-60-40-200204060-120-100-80-60-40-200204060-120-100-80-60-40-200204060-120-100-80-60-40-200204060-120-100-80-60-40-20020406029Si NMR of (Si-O)n oligomer unitsAtom-by-Atom Synthesis of Metal-Oxygen ChainChang, Kung, and Kung, Chem. Comm. submittted. 17Metal-Oxygen Backbo

12、ne of Designed Sequence and StructureOSiM18Molecular templating:A. Katz and M.E. Davis, Nature 403 (2000) 286. Introduce functional groups at specific locations in the cavity.Molecules diffuse through silica wall into and out of cavity.19Preparing sites with predetermined spacingDufaud and Davis, JA

13、CS 125 (2003) 940320Table 3. Synthesis of Bisphenol A with Sulfonic Acid Functionalized SBA-15 Silicas and para-Toluene Sulfonic AcidaVronique Dufaud* and Mark E. Davis* , J. Am. Chem. Soc., 125 (31), 9403 -9413, 200321What would one like to accomplish in total catalyst synthesis? Shape of the cavit

14、y Path to cavity Ability to design and position ancillary groups Complete atomic control of active site22Eliminated pore diffusion control, Little shape selectivity. A. Corma, U. Diaz, M.E. Domine, V. Forns, Angew. Chem. Int. Ed. 39 (2000) 1499.(h00)23K. Polborn and K. Severin, Chem. Commun. (1999)

15、2481-2482.Molecular ImprintingCat. 4 made from 2; control cat. 5 made from 124RPRPActive At restMolecular hinges to control accessibility of active sites25Figure 1 Molecular model of endoclucanase 12A and schematic model of the DMAAm-enzyme molecular switch. The red residues represent the catalytic

16、glutamic acid side chains at the active site of EG 12A, the green residue is the Asn 55 position, the purple residue is the Ser 25 position, and the N-terminus is represented as the blue circle. Tsuyoshi Shimoboji, Edmund Larenas, Tim Fowler, Allan S. Hoffman,* and Patrick S. Stayton* Bioconjugate C

17、hem., 14 (3), 517 -525, 200326Figure 4 Characterization of ONPC enzyme activities for free DMAAm-EG 12A conjugates in solution at as function of polymer size and conjugation site. The enzyme activities were measured for 100 nM conjugates using ONPC (8mM) as a substrate and normalized to the activity

18、 of N55C or S25C EG12A controls as 100% at each temperature. EG 12A-M10, 10 kDa DMAAm-EG12A conjugate; EG 12A-M6, 6 kDa DMAAm-EG 12A conjugate; EG 12A-M3, 3 kDa DMAAm-EG 12A conjugate; and EG 12A + M10, physical mixture of enzyme plus 10 kDa DMAAm. Tsuyoshi Shimoboji, Edmund Larenas, Tim Fowler, All

19、an S. Hoffman,* and Patrick S. Stayton* Bioconjugate Chem., 14 (3), 517 -525, 200327Molecular Switching via RedoxReduction by ascorbic acidOxidation with ammonium persulfateConformational change monitored by circular dichroismS. Zahn and J.W. Canary, Angew. Chem. Int. Ed. 37 (1998) 305-28V. Balzani,

20、 A. Credi, F.M. Raymo, J.F. Stoddart, Angew. Chemie Int. Ed. 39 (2000)334829J. Rebek, Jr. Acc. Chem. Res. 17 (1984) 258V. Balzani, A. Credi, F.M. Raymo, J.F. Stoddart, Angew. Chemie Int. Ed. 39 (2000)334830pH-Driven translocation of Ni(II) ionAmendola, Fabbrizzi, Mangano, Pallavicini, Acc. Chem. Res

21、. 34 (2001) 488.Translocation of metal ion is signaled by quenching/revival of the emission of fluorescent probe (anthracene substituent)31Mesoporous benzene-silicaS. Inagaki et al, Nature, 416 (2002) 304AlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAl

22、HRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHR

23、AlAlOOOHAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAl

24、AlOOOHAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOO

25、AlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAl

26、AlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOO

27、AlHRAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAl

28、AlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlOOOOAlHRAlOOOOAlAlOOOOAlHRAlAlOOOHAlOOOOAlHRAlOOOOAlHRAlOOOOAlHRAlAlOOOHAlO