Heterogeneously Catalyzed Oxidation Reactions Using ... - CHEC

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CHAPTER 2 Figure 2‐10: Product distribution obtained from Cu‐APO‐5 catalyzed toluene oxidation with H2O2 [31]. The use of TBHP as oxidant for activated alkyl aromatics allows for milder reactions conditions; almost quantitative conversion of diphenylmethane to benzophenone could be obtained with Cu‐ doped hydrotalcite as the catalyst under mild reaction conditions (60 °C, entry 4) [148]. As often observed, ACN solvent gave the best results by far with a TOF of 2.5 h ‐1 over 24 h. TBHP was also successfully used with the Cu3(BTC)2 metal‐ organic framework oxidizing xanthene to xanthone at 70 °C [149]. The very low TOF (0.02 h ‐1 , TON 0.56) might result from the inaccessibility of the MOF micropores to the substrate (Table 2‐4, entry 5). 2.3.3.2 Aerobic oxidation O O 4.3% 50% 18% Given that the use of molecular oxygen for this type of reaction is long established in industry, the most promising systems also involve the use of this inexpensive oxidant. Side chain oxidation of toluene results mainly in benzyl alcohol, benzaldehyde and benzoic acid, with benzaldehyde as the most valuable reaction product. High benzaldehyde selectivities require low toluene conversions. Two binary metal oxides involving Cu were found to be useful catalysts for toluene to benzaldehyde conversion. CuFe/Al2O3 was reusable for toluene oxidation with oxygen at elevated pressures and 190 °C (entry 6a) [150]. Under solventless conditions, a benzaldehyde selectivity of 46 % at 7.4 % conversion could be improved to 86 % (at 7.3 % conversion) by addition of pyridine. The authors suggest that pyridine hinders benzaldehyde adsorption to the catalyst surface thereby suppressing the oxidation to benzoic acid. At high conversions (25.4 %), benzoic acid could be synthesized with moderate selectivity (72 %, entry 6b). Interestingly, both OH 36 OH 27% O
Table 2-4: Side-chain oxidation of alkyl aromatic compounds. R1 R2 catalyst [Ox] R1 OH R + 2 O R + 2 O Entry Catalyst Substrate Oxidant Solvent T (°C) Rct. time (h) Conversion 1a* 1b* Cu-Al/montmorellite Cu-Al/montmorellite Al Selectivity a On b Ac c POx d Ring e TOF (h -1 ) Ref. toluene H2O2 ACN 92 1 27% - 29% - - 68% - [33] p-xylene H2O2 ACN 92 1 24% - 43% - - 53% - [33] 2a* Zn0.9Cu0.1/ LDH f toluene H2O2 ACN 60 1 15% 30% 70% - [147] 2b* Zn0.9Cu0.1/ LDH f p-xylene H2O2 ACN 60 1 19% 48% 52% - [147] 3a Cu-APO-5 toluene H2O2 ACN 60 3 14% 28% 72% 14 [31] 3b Cu-APO-5 4 Cu-HT ethylbenzenediphenylmethane H2O2 ACN 60 3 10% 48% 46% 8.3 [31] TBHP ACN 60 24 95% - 100% - - - 2.5 [148] 5 Cu3(BTC)2 xanthene TBHP ACN 70 24 96% - 85% - - - 0.02 [149] 6a CuFe/Al2O3 toluene O2 - 190 2 7.4% 24% 46% 27% - - - g [150] 6b CuFe/Al2O3 toluene O2 - 190 4 25% 1.0% 27% 72% - - - g [150] 7 CuxMnyO4 toluene O2 - 190 2 17% 17% 15% 62% - - - g [25] 8 Cu2O cumene O2 - 80 - - - - - - - 0.15 [151] 9 Ag2O/ α-Al2O3 ethylbenzene O2 - 70 - - - - - - - 8.5 [72] 10 Ag/CeO2-SiO2 toluene O2 - 170 1 2.6% h 42% 38% 19% - - 11 [91] 11 Ag/CeO2-SiO2 p-xylene O2 - 135 3 13.4% h 22% 19% 58% n.a. - 600 [91] 12 Ag/CeO2-SiO2 ethylbenzene O2 - 135 3 15% h 27% 45% - 28% - 670 [91] 13 Ag/CeO2-SiO2 cumene O2 - 135 3 2.3% h 4.3% 70% - 26% - 100 [91] *No standard use reported. a Alcohol. b Aldehyde/ ketone. c Carboxylic acid. d Peroxide. e Ring hydroxylation. f Layered double hydroxide. g TOF for catalysts with 2 active metals were not calculated. h Yield; selectivities calculated from yields. R 1 OOH OH + + Al On Ac POx Ring R 2 R 1 OH R 2
Page 1 and 2: TECHNICAL UNIVERSITY OF DENMARK (DT
Page 3 and 4: Preface The present dissertation su
Page 5 and 6: the carboxylic acid, ceria inhibite
Page 7 and 8: Resume Denne afhandling giver indle
Page 9 and 10: hvorimod mængden af katalysator ku
Page 11 and 12: 2.3.8 Oxidation of sulfides .......
Page 13 and 14: 5.3.5 Macroscopic mass transport in
Page 15 and 16: Chapter 1 Introduction With its gre
Page 17 and 18: 1. Introduction Scheme 1‐1: High
Page 19 and 20: 1. Introduction Figure 1‐2: Phase
Page 21 and 22: 1. Introduction [28] S. Bawaked, N.
Page 23 and 24: 2.1 Introduction 2.1 Introduction E
Page 25 and 26: 2.2.1 Synthesis of gold catalysts 2
Page 27 and 28: 2.2 Catalyst synthesis for oxidatio
Page 29 and 30: 2.2 Catalyst synthesis for oxidatio
Page 31 and 32: 2.3 Selective liquid‐phase oxidat
Page 33 and 34: Table 2-1: Overview over alcohol ox
Page 45 and 46: Ph O O Ph (4) (5) 2.3 Selective liq
Page 49: 2.3 Selective liquid‐phase oxidat
Page 53 and 54: 2.3.4 Oxidation of cyclohexane 2.3
Page 55 and 56: Table 2-5: Oxidatin of cyclohexane.
Page 59 and 60: Table 2-6: Ring hydroxylation of ar
Page 63 and 64: Table 2-7: Aerobic oxidation of ami
Page 65 and 66: Table 2-8: Oxidation of hydroquinon
Page 69 and 70: Table 2-9: Oxidation of silanes wit
Page 71 and 72: Table 2-10: Oxidation reactions cat
Page 73 and 74: 2.4 Strengths and opportunities of
Page 81 and 82: 2.6 References 2.6 References [1] M
Page 83 and 84: 2.6 References [56] H. Tumma, N. Na
Page 85 and 86: 2.6 References [113] C. Keresszegi,
Page 87 and 88: 2.6 References [169] Q. Zhu, Y. Lia
Page 89 and 90: 2.6 References [223] M. Fetizon, M.
Page 91 and 92: Chapter 3 Selective Liquid-Phase Ox
Page 93 and 94: 3.2 Experimental 3.2.1 Catalyst pre
Page 95 and 96: 3.3 Results Scattering amplitudes a
Page 97 and 98: Absorption (a.u.) 1.2 1.0 0.8 0.6 0
Page 99 and 100: Conversion (%) 100 90 80 70 60 50 4
Page 101 and 102:
3.3 Results Figure 3‐5: In situ X
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3.3 Results Table 3‐2: Conversion
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3.3 Results In order to gain insigh
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3.3 Results the cost of selectivity
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3.4 Discussion synergetic interacti
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3.5 Conclusions to corroborate the
Page 113 and 114:
3.6 References [29] T. Mitsudome, Y
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Chapter 4 Selective Side-Chain Oxid
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4.2 Experimental single‐step flam
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4.2 Experimental alcohol (Aldrich,
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4.3 Results Scheme 4‐1: Oxidation
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4.3 Results Figure 4‐2: Formation
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4.3 Results oxidation by either 2,6
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Absorption (a.u.) Absorption (a.u.)
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4.3 Results atomic mixing of Ag and
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4.3 Results Figure 4‐7: Influence
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4.4 Discussion and mechanistic cons
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4.5 Conclusions heterogeneous radic
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4.6 References [29] S.I. Zabinsky,
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Chapter 5 Experimental Determinatio
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5.2 Experimental The most important
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5.2 Experimental Eurotherm 2216e te
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Figure 5-1: Schematic view of the e
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(Eq. 5‐5) AB i j ε AB i j β 5.2
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(a) (b) (c) (d) (e) (f) (g) (h) (i)
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5.3 Results two association sites o
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Pressure (bar) 150 145 140 135 5.3
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5.3 Results Figure 5‐7: Oxidation
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Weight (g) 5.3 Results Figure 5‐8
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5.4 Discussion catalytic reactions
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5.4 Discussion corresponding CO2‐
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5.5 Conclusions 5.5 Conclusions The
Page 165 and 166:
5.6 References [29] I. Tsivintzelis
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6.1 Introduction 6.1 Introduction A
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6.2 Experimental [38]. In a typical
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6.3 Results out in 1 mm quartz tube
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6.3 Results Figure 6‐2: Structure
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6.3 Results Figure 6‐4: Epoxidati
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6.3 Results Figure 6‐6: Compariso
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6.3 Results Figure 6‐8: Influence
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6.3 Results investigated the epoxid
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6.3 Results Figure 6‐10: Co‐epo
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6.3 Results Figure 6‐11: EXAFS an
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6.4 Discussion would need to be for
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6.5 Conclusions Formation of the ep
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6.6 References [28] J. Perles, N. S
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Chapter 7 Concluding Remarks 7.1 Co
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7.2 Final remarks and outlook speci
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Acknowledgements Acknowledgements T
Page 199:
Curriculum Vitae Matthias Josef Bei
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