Design and Applications of Single-Site Heterogeneous Catalysts : Contributions to Green Chemistry, Clean Technology and Sustainability

by Thomas, John Meurig

• ISBN13: 9781848169098
• ISBN10: 1848169094
• Format: Hardcover
• Copyright: 2012-06-15
• Publisher: World Scientific Pub Co Inc

Summary

For far too long chemists and industrialists have relied on the use of aggressive reagents such as nitric and sulphuric acids, permanganates and dichromates to prepare the massive quantities of both bulk and fine chemicals that are needed for the maintenance of civilised life - materials such as fuels, fabrics, foodstuffs, fertilisers and pharmaceuticals. Such aggressive reagents generate vast quantities of environmentally harmful and often toxic by-products, including the oxides of nitrogen, of metal oxides and carbon dioxide.Now, owing to recent advances made in the synthesis of nanoporous solids, it is feasible to design new solid catalysts that enable benign, mild oxidants to be used, frequently without utilising solvents, to manufacture the products that the chemical, pharmaceutical, agro- and bio-chemical industries require. These new solid agents are designated single-site heterogeneous catalysts (SSHCs). Their principle characteristics are that all the active sites present in the high-area solids are identical in their atomic environment and hence in their energy of interaction with reactants, just as in enzymes.Single-site heterogeneous catalysts now occupy a position of growing importance both academically and in their potential for commercial exploitation. This text, the only one devoted to such catalysts, dwells both on principles of design and on applications, such as the benign synthesis of nylon 6 and vitamin B3. It equips the reader with unifying insights required for future catalytic adventures in the quest for sustainability in the materials used by humankind.Anyone acquainted with the language of molecules, including undergraduates in the physical and biological sciences, as well as graduates in engineering and materials science, should be able to assimilate the principles and examples presented in this book. Inter alia, it describes how clean technology and 'green' processes may be carried out in an environmentally responsible manner.

Table of Contents

Foreword	p. vii
Preface	p. ix
Acknowledgements	p. xiii
Permissions	p. xxiii
Basics and Background	p. 1
Introduction to the Salient Features of Single-site Heterogeneous Catalysts	p. 3
Lessons from the Biological World: The Kinship Between Enzymes and Single-site Heterogeneous Catalysts	p. 11
The Story of Lysozyme and Its Consequences	p. 11
Hybrid Enzymes	p. 15
Immobilized Enzymes	p. 16
The Kinship between Enzymes and SSHCs	p. 16
Distinctions between Single-site Heterogeneous Catalysts and Immobilized Homogeneous Catalysts	p. 23
Outline of Historical Background	p. 23
Metal Cluster Compounds as Molecular Precursors for Tailored Metal Nanocatalysts	p. 27
The Essence of Surface Organometallic Chemistry (SOMC)	p. 30
Highly Active Organometallic Catalysts Based on Self-assembled Monolayers	p. 36
Colloid-bound Organometallic Catalysts of Exceptional Activity	p. 37
Analogies with Single-site Homogeneous Polymerization Catalysts	p. 38
The Taxonomy of SSHCs: A Résumé	p. 40
Microporous Open Structures	p. 51
Microporous Open Structures for the Design of New Single-site Heterogeneous Catalysts	p. 53
Introduction	p. 53
The Salient Characteristics of Microporous SSHCs	p. 59
Some Examples of Acidic Microporous SSHCs	p. 64
Environmentally benign, solvent-free alkylations, acylations and nitrations using acidic SSHCs	p. 67
Brønsted acidic microporous SSHCs for hydroisomerization (dewaxing) of alkanes: designing new catalysts in silico	p. 69
Brønsted Acidic Microporous SSHCs for the Dehydration of Alkanols: Environmentally Benign Routes to Ethylene, Propylene and Other Light Alkenes	p. 74
Catalytic dehydration of ethanol using Brønsted acidic SSHCs	p. 75
The methanol-to-olefin conversion over Brønsted acidic SSHCs	p. 75
Structural and mechanistic aspects of the dehydration of isomeric butanols over porous aluminosilicate acid catalysts	p. 80
Lewis Acidic Microporous SSHCs for a Range of Selective Oxidations	p. 87
Cascade Reactions with TAPO-5	p. 88
One-pot reactions: a contribution to environmental protection using Lewis acid active sites	p. 90
Redox Active Sites in Microporous Solids	p. 92
Introduction	p. 92
Single-site redox active centres for the benign selective oxidation of hydrocarbons in air or 02	p. 93
Insights from Quantum Chemical Computations into the Mechanism of C-H Activation at MnIII Catalytic Centres in Microporous Solids	p. 102
Bifunctional Single-site Microporous Catalysts: A Solvent-free Synthesis of Caprolactam, the Precursor of Nylon 6	p. 107
Single-site Metal Cluster Catalysts Supported on a Microporous Host: Reactive Environments Influence the Structure of Catalysts	p. 109
Single-site Heterogeneous Catalysts for the Production of Pharmaceuticals, Agrochemicals, Fine and Bulk Chemicals	p. 121
Introduction	p. 121
Fine Chemicals and Pharmaceuticals	p. 122
Facile, one-step production of niacin (vitamin B3) and other nitrogen-containing chemicals with SSHCs	p. 122
Facile, one-step production of isonicotinic acid from 4-picoline	p. 125
Production of pharmaceutically important derivatives of quinoline	p. 127
Environmentally Benign Oxidative Methods of Producing Bulk Chemicals Using SSHCs	p. 128
The synthesis of benzaldehyde from toluene	p. 129
The one-step conversion of cyclohexane to adipic acid	p. 132
The one-step aerobic, solvent-free conversion of p-xylene to terephthalic acid	p. 134
Environmentally Benign, Brønsted Acid-catalysed Production of Bulk Chemicals with Microporous SSHCs	p. 136
Transformations Involving Lewis Acid Microporous Catalysts	p. 137
Conversions of sugars to lactic acid derivatives using Sn-based zeotypic SSHCs	p. 137
Single-site, Lewis acid microporous catalysts for the isomerization of glucose: a new efficient route to the production of high-fructose corn syrup	p. 140
Baeyer-Villiger Oxidations of Ketones to Lactones with SSHCs	p. 141
Introduction	p. 141
A redox SSHC for Baeyer-Villiger aerobic oxidations under Mukaiyama conditions	p. 142
Sn-centred single-site microporous catalysts for Baeyer-Villiger oxidations with H2O2	p. 144
The Crucial Role of Single-site Microporous Catalysts in New Methods of Synthesizing ¿-Caprolactam and Nylon 6	p. 145
Introduction	p. 145
The primacy of nylon 6	p. 145
Existing routes to the synthesis of ¿-caprolactam	p. 147
The design of a green, one-step production of ¿-caprolactam using a bifunctional SSHC	p. 149
Optimizing SSHCs for oxime production	p. 151
Envoi	p. 152
Mesoporous Open Structures	p. 157
Epoxidations and Sustainable Utilization of Renewable Feedstocks, Production of Vitamin E Intermediates, Conversion of Ethene to Propene and Solvent-free, One-step Synthesis of Esters	p. 159
Introduction	p. 159
A Comprehensive Picture of the Nature and Mechanism of the TiIV-catalysed Epoxidation of Alkenes	p. 162
Mechanism of the TiIV-centred epoxidation of alkenes	p. 165
An alternative method of introducing isolated Ti centres to mesoporous silica	p. 169
The use of H2O2 over TiIV-grafted mesoporous silica catalysts: a further step towards sustainable epoxidation	p. 171
TiIV mesoporous catalysts have an important role to play in a sustainable way to utilize renewable feedstocks from fats and vegetable sources	p. 173
Other Examples of Single-site, Metal-centred Catalysts Grafted onto Mesoporous Silica	p. 175
Titanium Cluster Sites for the Production of Vitamin E (Benzoquinone) Intermediates	p. 176
Single-site Metal Complexes Grafted onto Mesoporous Silica	p. 179
Stability and recyclability of supported metal-ligand complex catalysts: a critical note	p. 181
A Trifunctional, Mesoporous Silica-based Catalyst: Highly Selective Conversion of Ethene to Propene	p. 182
Hybrid SSHCs are Chemically Robust	p. 183
The Confluence of Heterogeneous and Homogeneous Catalysis Involving Single Sites	p. 184
Beyond Mesoporous Silica	p. 188
The merits of clay-based single-site catalysts	p. 188
Pillared zeolites?	p. 191
Envoi	p. 192
Exploiting Nanospace for Asymmetric Conversions	p. 201
Background	p. 201
Whither Chiral Zeolites?	p. 202
Chiral Metal-organic Frameworks (MOFs)	p. 206
Harnessing the Asymmetric Catalytic Potential of Mesoporous Silicas Using SSHCs	p. 210
Background	p. 210
Exploiting nanospace for asymmetric catalysis: confinement of immobilized single-site chiral catalysts enhances enantioselectivity	p. 212
Asymmetric hydrogenation of E-¿-phenylcinnamic acid and methyl benzoylformate: the advantages of using inexpensive diamine asymmetric ligands	p. 219
One step is better than two	p. 221
Epilogue	p. 225
Multinuclear, Bimetallic Nanocluster Catalysts	p. 233
Definitions: Nanoclusters are Distinct from Nanoparticles	p. 233
Bimetallic nanoclusters and bimetallic nanoparticles are not alloys	p. 235
The Merits of Studying Bimetallic Nanocluster Catalysts	p. 236
Why Focus on Bimetallic Catalysts Based on Platinum Group Metals (PGMs)?	p. 241
Specific Examples of High-performance Bimetallic Nanocluster Catalysts for Selective Hydrogenations under Benign Conditions	p. 244
Bimetallic nanocluster catalysts for ammoxidation	p. 246
Bimetallic nanocluster catalysts for the (sustainable) synthesis of adipic acid	p. 247
Bimetallic and Trimetallic Nanocluster Catalysts Containing Tin: The Experimental Facts	p. 249
Quantum Computational Insights	p. 249
The computational method	p. 253
Assessing the structure and electronic properties of Ru5PtSn in the gas phase and when supported on silica (cristobalite)	p. 253
Quantum insights into the structure and densities of states of RunSnn (n = 3 to 6) clusters in the gas phase	p. 258
Comparisons with Nanocluster Catalysts Involving Gold, Platinum, Palladium and Iridium	p. 260
Nanocluster catalysts of palladium and iridium	p. 265
The role of the catalyst support	p. 267
Envoi	p. 268
Reference Works Dealing With Green Chemistry, Clean Technology and Sustainability	p. 277
Index	p. 281
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