Providing sustainable catalytic solutions for a rapidly changing world

09:05-09:30 Non-thermal plasma activated catalysis for low temperature operation

Professor Chris Hardacre, University of Manchester, UK

Abstract

Hybrid non-thermal plasma catalysis has a significant potential to provide a low energy pathway to activate molecules and catalysts to enable processes to operate at lower temperatures than would occur if activated thermally. This presentation will show how plasma activation can be utilised to promote the water gas shift reaction, deNOx reactions and methane combustion. The role of the plasma will be explored and the mechanism of thermal vs plasma activated processes will be shown.

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09:45-10:15 Alkane partial oxidation using dioxiranes in solution at low temperatures

Dr Sara Yacob, Exxon Mobil, USA

Abstract

Direct catalytic partial oxidation of alkanes, such as methane, in the gas phase can often require high temperatures for activation of the strong aliphatic C–H bond. High temperature reaction conditions can frequently lead to gas phase radical reactions, with intrinsically low selectivity and poor control of yields. However, partial oxidation catalysts capable of efficiently operating at low temperatures may limit the over-oxidation of the alkane substrate and thereby improve selectivity. Frequently, when supported transition metal catalysts are used for C–H bond activation, irreversible deactivation via metal reduction, particle sintering, or coke deposition is observed. Therefore, this study focuses on examining alkane oxidation using completely metal-free organocatalysts, dioxiranes, in solution at low temperatures. Typical dioxiranes, such as dimethyldioxirane and methyl(trifluoromethyl)dioxirane, can be prepared by oxidation of the parent ketone so that the dioxirane can be added as isolated species, however, in this manner the dioxirane serves only as a stoichiometric oxidant. This work aims to generate dioxirane in situ so that the process can be catalytic with respect to the ketone using H2O2 as the stoichiometric oxidant.

11:00-11:45 TiO2 and ZrO2 in biomass conversion: why catalyst reduction helps

Professor Gianfranco Pacchioni, University of Milano-Bicocca, Italy

Abstract

Reducible oxides are considered to be more active than non-reducible oxides in catalytic conversion of biomass to biofuels, but the reasons are unclear and are the object of this talk. The properties of anatase TiO₂ and tetragonal ZrO₂ (101) surfaces have been studied using DFT+D calculations with inclusion of dispersion forces. The attention is on the role of surface reduction, either by creation of oxygen vacancies, or by treatment in hydrogen. The presence of reduced centers on the surface of titania or zirconia (either Ti³⁺ or Zr³⁺ ions or oxygen vacancies) results in lower barriers and more stable intermediates in two key reactions in biomass catalytic conversion: ketonization of acetic acid and deoxygenation of phenol. The role of supported Ru nanoparticles is also considered. They favour H₂ dissociation and hydrogen spillover, resulting in hydroxylated surfaces. H₂O desorption from the hydroxylated surfaces may be a relevant mechanism for the regeneration of oxygen vacancies, in particular on low-coordinated sites of oxide nanoparticles. Finally, the role of nanostructuring on oxide reduction is discussed. ZrO₂ nanoparticles of diameter of about 2 nm have completely different behaviour compared to the bulk oxide, and are much more reducible. Nanostructured zirconia has a similar behaviour as titania.

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11:45-12:15 A deeper understanding of structured Co-Fischer Tropsch Synthesis catalysts via chemical tomography

Professor Andy Beale, University College London, UK

Abstract

The imaging of catalysts under reaction conditions has advanced significantly in recent years. The combination of the computed tomography (CT) approach with methods such as X-ray diffraction (XRD), X-ray fluorescence (XRF), and X-ray absorption near edge spectroscopy (XANES) now enables local chemical and physical state information to be extracted from within the interiors of materials which are, by accident or design, inhomogeneous. The spatially resolved signals obtained reveal information otherwise lost in bulk measurement. Studying intact materials rather than idealised powders allows for behaviour under industrially relevant conditions to be observed. Such methods have been applied to study catalytic systems over a range of length scales (from ~1 µm to 10 mm). On small length scales (<200 µm), X-ray transmission at ‘low’ energies (<10 keV) is possible and allows for performing multi-modal imaging (i.e. combined spectroscopic and diffraction imaging) on packed-bed micro-reactors (Co/SiO2 FTS catalysts) enabling for a more inclusive correlation of catalyst composition with performance. On larger length scales (i.e. >few mm) high energy scattering computed-CT enables large/dense objects to be studied i.e. 3 mm Co/g-Al2O3 pellets. This information is vital to rational catalyst and reactor design that cannot be obtained by conventional bulk measurements.

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13:30-14:00 Novel catalysts for H2O2 synthesis and their utilisation in wastewater treatment

Dr Jenny Edwards, University of Cardiff, UK

Abstract

The direct synthesis (DS) of hydrogen peroxide from H₂ and O₂ presents an atom efficient route to an important commodity chemical if the reaction proceeds with high H₂ selectivity. Supported bimetallic nanoparticles are known to be highly active and selective for this reaction. The composition of the particles, catalyst support and reaction conditions result in catalysts with <99% H₂ selectivity, and materials which no not over hydrogenate the H₂O₂ formed to water. One potential application of the DS process is to produce H₂O₂ in quantities sufficient to eradicate bacteria present in a greywater stream. Roughly 50% of the average household’s water is greywater (effluent originating from washing machines, dishwashers etc ) and it’s possible a small system capable of producing H₂O₂ in this stream would be enough to reduce harmful microorganisms present so the water can be reused within the household. For such system to be viable, the H₂O₂ would need to be formed under challenging conditions (ambient temperature, pressure in a water only solvent system) and it is likely new catalyst formulations will be required (where H₂O₂ is catalytically decomposed to radicals). Advances towards these targets will be discussed in this lecture.

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14:15-14:45 Mechanistic insights into catalytic synthesis of hydrogen peroxide over supported metals

Professor Matt Neurock, University of Minnesota, USA

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15:30-16:00 Photocatalysis for combined destruction of organic and inorganic pollutants from aqueous environments

Professor Jim Anderson, University of Aberdeen, UK

Abstract

The lecture will attempt to provide an overview of the latest developments in the rapidly expanding field of water purification via photocatalytic methods and in particular, focus on the removal of nitrate ions with simultaneous removal of the hole scavenger (organic moiety). While many of the issues associated with provision of potable water in the developing world may be resolved by the use of simple physical methodologies such as filtration, many of the issues associated with water purity in the developed world involve complex, stable molecules present at low concentrations but nonetheless capable of producing toxic effects in plants and animals and which require removal technologies which are more demanding. Photocatalytic methods can be operated remotely and initial studies show minimal production of undesired side products. Studies using titania alone as a photocatalyst show limitations, not only in terms of the slow rate of photoreduction of nitrate but also in terms of selectivity and the need to employ radiation in the UV region due to the magnitude of the band gap. The key challenges may be defined as: reduce band gap/increase absorption in visible region, increase adsorption capacity/access to surface active sites, reduce rate of hole/electron recombination, enhance activity.

09:00-09:30 Selective and robust polymerisation catalysts for sustainable bioplastics

Professor Matthew Davidson, University of Bath, UK

Abstract

As the global demand for plastics is set to triple over the next 30 years, decoupling plastics production from fossil feedstocks will become an increasingly important challenge. Therefore, the use of bio-based resources for the production of plastics is highly active area of research in both academia and industry. Polylactide (PLA), produced via the catalytic ring-opening polymerization (ROP) of lactide, is one of the most promising alternatives to petrochemically-derived plastics for commodity applications such as packaging and fibres. Progress in developing new stereoselective catalysts for ROP of lactide has been impressive, but industrial application of these catalysts is currently limited. This talk will focus on the development of zirconium-based catalysts for industrial PLA production. The design of new stereoselective catalysts, understanding of the mechanism of stereocontrol and the development of new synthetic strategies for control of polymer architecture will be discussed in the context of broadening the scope of PLA as a commodity bio-based plastic.

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09:45-10:15 Integrating biocatalyst and process design

Professor John Woodley, Technical University of Denmark, Denmark

Abstract

Biocatalysis uses enzymes for chemical synthesis and production, offering selective, safe and sustainable catalysis. While today the majority of applications are in the pharmaceutical sector, new opportunities are arising every day in other industry sectors, where production costs become a more important driver. In the early applications of the technology it was necessary to design processes to match the properties of the biocatalyst. With the advent of protein engineering that paradigm has changed into one where the biocatalyst can be designed to match the process. Progress has been spectacular, but in recent years the route to industrial implementation has become increasingly dependent upon timely protein engineering to enable the tailored design of a given biocatalyst. Today a new era is entered, where the effectiveness with which such protein engineering is achieved becomes critical to implementation. In this lecture two methods to improve this will be described. The first involves the development of target-setting based on process requirements to guide protein engineering. The second involves the simultaneous solution of the biocatalyst and process design problems. Illustration of both approaches will be given in the lecture.

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11:00-11:30 Protein engineering as a tool to create highly selective transaminases and application of biocatalysts in cascade reactions

Professor Uwe Bornscheuer, University of Greifswald, Germany

Abstract

This talk will highlight principle strategies and current challenges in enzyme discovery and protein engineering. These will be exemplified for amine transaminases (ATA) where Bornscheuer’s group took advantage of the vast number of protein sequences available from databases to facilitate the discovery of novel enzymes and to guide the design of 'small, but smart' mutant libraries. For the synthesis of chiral amines, Bornscheuer performed an in silico analysis and identified a toolbox of novel (R)-selective ATAs as well as (S)-selective enzymes from a structure-guided search. More recently, his group could engineer (S)-selective ATA for the acceptance of bulky ketones for the asymmetric synthesis of a set of important chiral amines. The group also established cascade reactions and developed for instance the efficient synthesis of ε-caprolactone-oligomers through combination of three enzymes.

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11:45-12:15 Efficient utilization of renewable feedstocks: the role of catalysis and process design

Professor Regina Palkovits, RWTH Aachen University, Germany

Abstract

Biomass presents a promising renewable feedstocks for production of fuels and chemicals. In recent years, the interest in a tailored valorisation of lignocellulose, the major component of biomass, has increased significantly. However, selective transformations are hampered by the high degree of functionalization of renewable feedstocks. Indeed, solid catalysts in current refinery technologies have been optimized to functionalize non-polar substrates in gas-phase reactions at elevated temperature. In contrast, renewable feedstocks exhibit a multitude of functional groups necessitating selective de-functionalization strategies in low-temperature liquid phase reactions with high polar solvents. Concepts such as selective adsorption, deoxydehydration as novel catalytic strategy, as well as solid molecular catalysts in H₂ production from formic acid as well as CO₂ activation will be discussed.

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13:30-14:00 Computer-aided design of novel catalysts for sustainable energy production

Professor Nora de Leeuw, Cardiff University, UK

Abstract

Computer modelling is an extremely useful tool to investigate structures and processes that are inaccessible experimentally and to help interpret experiment. Furthermore, computational techniques are increasingly truly predictive in identifying promising materials and processes for specific applications. Here, de Leeuw presents a computational study of promising catalysts for sustainable energy production. Carbon dioxide capture and utilisation is gaining significant attention, not only driven by environmental factors but also by the potential to exploit it as chemical feedstock. One plausible utilisation route is its conversion to small organic molecules as pre-cursors to fuels and chemicals, but CO₂ is thermodynamically very stable and its reduction is energy-intensive. However, CO₂ conversion does take place under mild conditions in chemoautotrophic bacteria catalysed by enzymes. These enzymes often contain Fe₄S₄ cubane clusters, which have been shown to act as electron-transfer sites, but they can also be catalytically active centres for molecule transformations. A number of iron sulphide mineral are structurally similar to this cluster – a fact that suggests that they may well be a suitable heterogeneous catalyst. Here, de Leeuw presents a combined theoretical and experimental investigation of cubane-structured iron sulphide minerals as potential catalyst in the transformation of CO₂ into organic molecules.

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14:15-14:45 Catalyst control to allow selective polymerizations from mixtures: a useful strategy to deliver future materials?

Professor Charlotte Williams, University of Oxford, UK

Abstract

Catalysis plays a central role in delivering materials from renewable resources and this lecture addresses the alternating copolymerization of epoxides and carbon dioxide. Central to applying such materials is to understand and improve the physical-chemical properties. Here, the opportunity to use homogeneous catalysts to deliver block sequence controlled materials from mixtures of monomers is examined. The strategy applies a single catalyst and mixtures of epoxides, carbon dioxide, anhydrides and lactones to prepare materials with controllable and predictable block sequences. The factors underpinning catalytic selectivity are examined by both experimental and theoretical methods.  Furthermore the catalysis is exploited to prepare oxygenated polymers suitable for higher end commodity applications such as thermoplastic elastomers and shape memory materials. The lecture the potential for controlled polymerization catalysis to deliver new sustainable materials showing high performances for a range of applications.

15:30-16:00 Sustainable industrial catalytic processes: the importance of innovation in large scale chemical manufacture

Dr Paul Collier, Johnson Matthey, UK

Abstract

Developing sustainable processes for industry is a key target for both academic and industrial researchers.  There are a small number of large sale chemicals that account for the majority of greenhouse gas emissions from the chemical industry, such as ammonia, ethylene or methanol.  This talk will discuss the concept of sustainability in an industrial context and highlight progress towards improved sustainability in large scale chemical processes such as methanol synthesis and nitric acid manufacture.

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16:15-17:00 Meeting Overview: future directions led by Professor Sir John Meurig Thomas FRS (Cambridge) and Professor Ted Oyama (University of Tokyo/Crest)

Professor Sir John Meurig Thomas HonFREng FRS, University of Cambridge, UK
Professor Ted Oyama, CREST, University of Tokyo, Japan

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