Heterogeneously Catalyzed Oxidation Reactions Using ... - CHEC

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2.3.4.1 Gold catalysts CHAPTER 2 At conditions comparable to industry, TOFs for the gold catalyzed oxidation of cyclohexane are reported to be in the range of several thousand per hour e.g. with Au/ZSM‐5 (Table 2‐5, entry 1) [160], Au/SBA‐15 (entry 2 and 3) [161, 162], Au/MCM‐41 (entry 4) [163], Au/SiO2 (entry 5) and Au/SiO2‐TiO2 [164], Au/Al2O3 (entry 6) [165] and Au/SiO2‐Al2O3 (entry 7) [166]. In the industrial process, high cyclohexane conversion is avoided since the selectivity to K/A oil drops significantly when exceeding 4 %. With the cited Au catalysts overall K/A selectivities higher than in the industrial case at higher conversions are reported. The group of Hutchings investigated the reaction at low temperatures (70 °C) where TBHP was necessary as a radical initiator [159]. As in the industrial case the K/A selectivity was merely a function of conversion, a general conclusion being that gold is not exceptionally active for this reaction (Table 2‐5, entry 8). Hereijgers et al. [156] investigated various supported Au catalysts finding gold to act only as an initiator for a radical autoxidation of cyclohexene (entry 9). Gold was neither especially selective nor active giving similar conversions as unpassivated autoclave steel (Figure 2‐11). The high calculated TOF also found here was mainly a consequence of the nature of a radical reaction at the high temperatures which is only initiated by gold and maintains itself. In combination with homogeneous Co, Au supported on SBA‐15 even inhibited the reaction to a certain extend. Contrary to many other cyclohexane oxidation studies, product analysis was done monitoring both gaseous and liquid products thereby providing very reliable results in terms of the industrially important selectivities. Figure 2‐11: Cylohexane conversion vs. time on stream during cyclohexane autoxidations (open symbols) and catalyzed oxidation (solid symbols) at 150 °C and 1.2 – 1.5 MPa [156]; reprinted with permission from Elsevier © 2010. 40
Table 2-5: Oxidatin of cyclohexane. Entry Catalyst Oxidant Solvent T (°C) Rct. time (h) Conversion Selectivity TOF Ref. 1* Au/ZSM-5 O2 - 150 3 15% 92% 2,800 [160] 2* Au/SBA-15-f a O2 - 150 3 16% 84% 12,000 [161] 3* Au/SBA-15-f a O2 - 150 2 17% 92% 6,000 [162] 4* Au/MCM-41 O2 - 150 3 12% 97% 11,000 [163] 5* Au/SiO2 O2 - 150 3 9.2% 83% 110,000 [164] 6* Au/Al2O3 O2 - 150 3 12.6% 85% 16,000 [165] 7* Au/SiO2-Al2O3 O2 - 150 3 8.7% 89% 2,700 [166] 8 Au/graphite b O2 - 70 17 1% 92% 18 [159] 9* Au/SBA-15 O2 - 150 1.5 4% 71% 2,000 [156] 10* Ag/MCM-41 O2 - 155 3 11% 83% 600 [80] 11 Ag-V-POM O2 scCO2/MeOH 180 8 10% 96% c - [167] 12 Cu-MCM-41-f a H2O2 acetone 100 12 4.8% e - 1.7 [37] 13 Cu-TUD-1 TBHP - 70 24 14% 81% ~7 h -1 [172] 14 Cu-mp-SiO2 d TBHP - 75 24 4.2% 85% 5.7 [173] 15* Cu-ZSM-5 TBHP Ionic liquid [emim]BF4 90 12 9.5% 100% 6 [174] 16 Cu-OMS-1 f TBHP tert.-butanol 80 40 10% 78% 1.7 [32] 17* Cu-Zn-Cr-spinel TBHP ACN 70 10 17% 71% - [175] 18 Cu2P2O7 H2O2 ACN 65 8 59% 100% 1.8 [176] 19a Cu/TiO2 O2 - 120 24 12% 63% 8 [177] 19b Cu/Al2O3 O2 - 120 24 14% 67% 10 [177] 19c Cu/Fe2O3 g O2 - 120 24 14% 69% 10 [177] 20 Cu-ZSM-5 O2 - 100 4 6.3% 75% 180 [27] *No standard use reported. a Organo-functionalized. b Catalytic amount of TBHP/1,4-difluorobenzene added. c Selectivity to partially oxygenated products. d Microporous silica. e Yield. f Octahedral molecular sieve. g Strong deactivation.
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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 51 and 52: Table 2-4: Side-chain oxidation of
Page 53: 2.3.4 Oxidation of cyclohexane 2.3
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
Page 103 and 104: 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
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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
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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
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Curriculum Vitae Matthias Josef Bei
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