NSC94-EPA-Z-008-004

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Figure 2.18 The synthesis mechanism proposed by Chen et al., 1993.Figure 2.19 The synthesis mechanism proposed by Monnier et al., 1993.14
Figure 2.20 The synthesis mechanism proposed by Firouzi et al., 1995.A little acidification results in a mixed lamellar-hexagonal phase in which layers ofhexgonally arrange rod-like micelles are separated by bilayers of surfactants and water(Figure 2.20A). Further acidification leads to the condensation of silicates and chargeimbalance on membrane surface, favoring the curvature of the membrane along only ondirection (Figure 2.20B) because of the intrinsically anisotropic membrane layers. Finally,neutralization will then bend the membrane completely into tubules (Figure 2.20C). Thedriving force arises from the imbalance charge at the surface which is associated with thecondensation reaction of the silicate-oxygen bond as the pH is lowered.Due to the inactive property of the MCM-41 synthesized with only pure silicon, Al, Ti,V, Sb, Fe, Pd, (Huo et al., 1994(a). Corma et al., 1994(a)) or Ga (Cheng et al., 1996) was usedto take place of the silicon position and became the active site in MCM-41. Substitution of Tiis particularly interesting because of the success of Ti-substituted zeolites in oxidation ofvarious organic substrates. TS-1 and TS-2 with MFI and MEL structures respectively wereshown to be active and selective catalysts for oxidation of phenol to catechol andhydroquinone (Reddy et al. 1990; Thangaraj et al., 1991). The synthesis of the large-porezeolite Ti-Beta with channels about 0.7 nm was reported. (Camblor et al., 1992; Camblor etal., 1993). It was able to oxidize cycloalkanes, cyclohexenes, and cycloalcohols moreefficiently than TS-1 zeolite (Blasco et al., 1993, Corma et al., 1994(b)). Using Ti zeolites asselective oxidation catalysts of fine chemicals, there was a need for producing molecular sieve15
Page 8 and 9: Figure 4.6 25-TiMCM-41 Isothermal P
Page 10 and 11: List of TablesTable 2.1 The compari
Page 12 and 13: Chapter2. Literature Review2.1 Cata
Page 14 and 15: In order to know exactly the influe
Page 16 and 17: exhibit different structures and re
Page 18: The different properties in H 2 O a
Page 22 and 23: Figure 2.16 MCM-41 structure with h
Page 26 and 27: catalysts with pore diameters large
Page 28 and 29: Chapter3. Experimental3.1 Chemicals
Page 30 and 31: 3.4 Characterization(1) X-ray Diffr
Page 32 and 33: Na2O‧ 2SiO2‧nH2O +H2OmixingTi s
Page 34 and 35: Chapter4. Results and Discussion4.1
Page 36 and 37: different opinion about the equidis
Page 38 and 39: Figure 4.3 XRD patterns of 50-TiMCM
Page 40 and 41: 350Volume Adsorbed cm 3 /g STP30025
Page 42 and 43: Table 4.2 Wall thickness of TiMCM-4
Page 44 and 45: 2.01.6MCM-4125-TiMCM-4175-TiMCM-41T
Page 46 and 47: 4.2 Photoreduction under visible li
Page 48 and 49: Intensity (arb. units)CB0 10 20 30
Page 50 and 51: (C) 1.0 wt% NiO/InVO 4Figure 4.17 T
Page 52 and 53: Table 4.3 The nominal and actual lo
Page 54 and 55: 4.2.2 Effect of reduction-oxidation
Page 56 and 57: Intensity (arb. units)CB0 10 20 30
Page 58 and 59: (C) 1.0 wt% NiO/InVO 4 R500-O200Fig
Page 60 and 61: 2.4Methanol yield (μmol g -1 h -1
Page 62 and 63: Chapter6. ReferencesAlfredsson, V.;
Page 64 and 65: Mesoporous Molecular-Sieves Snthesi
Page 66 and 67: 劃暨子計劃一主持人
Page 68: 子計畫 ); 系統放大設

NSC94-EPA-Z-008-004

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