Catalysts are molecules that participate in a chemical reaction to speed it up but are not consumed in the process. They are vital to everyday life enabling scientists to make the products we need to survive - drugs, plastics, clothing. A well know catalytic example is the Haber-Borsch process which provides ammonia for fertiliser that ultimately helps feed the half the world. This man-made nitrogen fixation process requires high temperatures and pressures using 1-2% of the world's energy supply. In contrast, plants perform nitrogen fixation at ambient temperatures and pressures using metalloenzymes. Enzymes and metalloenzymes are nature's catalysts: proteins that have evolved over time to be highly selective and efficient catalysts for making a wide range of products from abundant natural resources, such as sugars, water, and air. Chemists have long sought to mimic enzymes in pursuit of the ideal catalyst for a sustainable chemical future providing for society's needs. Artificial metalloenzymes (ArMs), that combine enzymes and organometallic catalysts, present an exciting opportunity to obtain the ideal catalyst by introducing unprecedented chemical reactivity into metalloenzymes, preserving the benefits of enzymes whilst widening their synthetic utility. Metal catalysts allow a wide range of reactions to occur, including the activation of inert C-H bonds (also known as C-H functionalisation). The transformation of two C-H bonds into a C-C bond represents one of the most efficient transformations available to chemists with only two hydrogen atoms generated as waste. These reactions have enormous potential in reducing waste and also in reducing the number of chemical steps required for product formation by avoiding the need to activate the C-H bond before C-C bond creation, thus lowering the energy and time costs of synthesis. C-H functionalisation reactions are difficult to carry out selectively as many C-H bonds are present in the starting molecules and the innate selectivity of the molecule is not always the desired selectivity for product formation. By carefully modelling and designing new metal centres into protein scaffolds, I will create ArMs, which use the protein scaffold to influence the active site environment and lead to high control of selectivity. One advantage of using ArMs is that they are encoded by DNA allowing the selectivity and activity to be rapidly optimised using directed evolution - a method based on natural selection. Using this approach, I will create highly selective and active ArMs for C-H functionalisation reactions. The genetic nature of the ArMs also allows them to be transferred into bacterial cells to carry out unnatural chemical reactions within a cell. I aim to introduce these artificial metalloenzymes into novel biosynthetic pathways to provide access to unnatural 'natural' products and other complex molecules. The ArMs developed in this project will have the potential to introduce unnatural activities into living organisms, and can be applied in areas beyond chemical synthesis including energy, biomaterials and health applications.

Despite the high thermodynamic stability of CO2, biological systems are capable of both activating the molecule and converting it into a range of organic molecules, all of which under moderate conditions. It is clear that, if we were able to emulate Nature and successfully convert CO2 into useful chemical intermediates without the need for extreme reaction conditions, the benefits would be enormous: One of the major gases responsible for climate change would become an important feedstock for the chemical and pharmaceutical industries! Iron-nickel sulfide membranes formed in the warm, alkaline springs on the Archaean ocean floor are increasingly considered to be the early catalysts for a series of chemical reactions leading to the emergence of life. The anaerobic production of acetate, formaldehyde, amino acids and the nucleic acid bases - the organic precursor molecules of life - are thought to have been catalyzed by small cubane (Fe,Ni)S clusters (for example Fe5NiS8), which are structurally similar to the surfaces of present day sulfide minerals such as greigite (Fe3S4) and mackinawite (FeS).Contemporary confirmation of the importance of sulfide clusters as catalysts is provided by a number of proteins essential to modern anaerobic life forms, such as ferredoxins, hydrogenases, carbon monoxide dehydrogenase (CODH) or acetyl-coenzyme A synthetase (ACS), all of which retain cubane (Fe,Ni)S clusters with a greigite-like local structure, either as electron transfer sites or as active sites to metabolise volatiles such as H2, CO and CO2. In view of the importance of (Fe,Ni)S minerals as catalysts for pre-biotic CO2 conversion, we propose employing a robust combination of state-of-the-art computation and experiment in a grand challenge to design, synthesise, test, characterise, evaluate and produce for scale-up novel iron-nickel sulfide nano-catalysts for the activation and chemical modification of CO2. The design of the (Ni,Fe)S nano-particles is inspired by the active sites in modern biological systems, which are tailored to the complex redox processes in the conversion of CO2 to biomass.The scientific outcome of the Project will be the design and development of a new class of sulphide catalysts, tailored specifically to the reduction and conversion of CO2 into chemical feedstock molecules, followed by the fabrication of an automated pilot device. Specific deliverables include:i. Atomic-level understanding of the effect of size, surface structure and composition on stabilities, the redox properties and catalytic activities of (Fe,Ni)S nano-catalysts;ii. Development of novel synthesis methods of Fe-M-S nano-clusters and -particles with tailored catalytic properties (M = Ni and other promising transition metal dopants);iii. Rapid production and electro-catalytic screening of lead nano-catalysts for the activation/conversion of CO2;iv. Development and application of a new integrated design-synthesis-screening approach to produce effective nano-catalysts for desired reactions;v. Construction of a prototype device capable of catalysing low-temperature reactions of CO2 into products at typical low-voltages, that can be obtained from solar energy; vi. Identification of optimum process for scale-up in Stage 2, from the Economic, Environmental and Societal Impact evaluationThe target at the end-point of Stage 1 is the fabrication of a photo-electrochemical reactor capable of harvesting solar energy to (i) recover CO2 from carbon capture process streams, (ii) combine it with hydrogen, and (iii) catalyse the reaction into product. In Stage 2 of the project, the prototype will be developed into a scaled-up commercially viable device, using optimum catalyst(s) in terms of (i) reactivity/selectivity towards the desired reaction; (ii) economic impact; and (iii) environmental, ethical and societal considerations.

The proposed research is part of a research study on the development of a diesel engine emissions reduction system with enhanced performance by utilisation of hydrogen produced on-board by exhaust gas fuel reforming. The research is motivated by the requirement of diesel engines to meet future emission regulations and by the potential of on-board exhaust gas fuel reforming to provide a way of improving diesel combustion and emissions as well as increasing the efficiency of diesel engine aftertreatment devices.The system targets are to achieve HC, CO and particulate matter (PM) emissions reduction of >90% using a diesel oxidation catalyst (DOC) and a diesel particulate filter (DPF), respectively, and NOx reduction of >70% using lean NOx catalyst technology (HC-SCR or NH3-SCR or NOx trap). The system will have to be cost effective (i.e. use of base metal catalyst or reduced precious metal catalyst content) and should operate without the need of specific engine map development.Specifically, the purpose of the present proposal is to extent the scientific knowledge on PM aftertreatment assisted by reformate addition that will allow successful integration of the DPF and reforming technologies.The study unfolds into two main parts: i) investigation of the use of reformate to promote the soot oxidation and hence improve the DPF regeneration at low exhaust gas temperatures (Brunel University) and ii) investigation of the improvement of DPF regeneration by soot oxidation with NO2 achieved through promotion of the low temperature NO to NO2 conversion rates in a DOC situated upstream of the DPF by addition of small quantities of reformate (University of Birmingham).By extending the understanding of the fundamental processes occurring during NO oxidation and filter regeneration, new catalysts and catalytic systems will be designed and guidelines for the further stages of the research programme towards a full working diesel engine - fuel reformer - aftertreatment system will be developed.

The chemistry of carbon monoxide (CO) and carbon dioxide (CO2) is deeply embedded in our future plans for energy production, chemical manufacturing and sustainable living. Remediation of CO2 has become a major topic of research in the last ten years and conversion of CO to hydrocarbons is already being applied on vast scales in industry. Catalysis underpins the development of this industry. COx-to-fuels, COx-to-molecules and COx-to-materials (x = 1 or 2) research is indispensable for the growth of the economy, improvement of quality of life, and regulation of gas emissions that contribute to climate change. Arguably the most established technology operating in this landscape if Fischer-Tropsch (F-T) catalysis. The F-T process converts mixtures of CO and H2 into short to medium chain hydrocarbons. Recent research has focused on the use of CO2 rich gas streams. This reaction can be considered as a controlled polymerisation and hydrogenation of CO / CO2 to generate liquid fuels. Despite its advantages, F-T catalysis produces simple alkanes and alkenes, not complicated molecules. Carbon chain formation occurs alongside removal of the oxygen atoms, in the form of H2O, reducing complexity and value. F-T does not capitalise on the potential chemical intricacy that could be introduced when combining COx units to form chains. In this project we will develop an entirely new approach to use CO and CO2 in chemical manufacture. We plan to exploit a remarkable recent finding from our labs (JACS, 2018, 13614): that carbon chains of 3 to 4 units of length can be grown from CO and CO2 on organometallic networks. We will develop underpinning science to discover the rules for chain growth. We will deliver new approaches to generate small carbon chains from CO and CO2 with control of size and shape. The new carbon chains will be exploited in synthesis as the major molecular component in the construction of complex organic molecules. The long-term vision behind this project is the development of a modern approach in catalysis that is complementary to both F-T processes and CO2-to-materials research. One that builds molecular complexity from CO and CO2. This proposal describes a three-year project that represents the first steps from discovery toward this goal.

The Stern report stresses that that the drive to more sustainable energy and the introduction of new technologies in this area must be urgently pursued. Fuel cells have a key role to play in the future energy economy. However, one of central components in many fuel cells is the precious metal electrodes which are very expensive, such that their longevity and high expense often limit fuel cell economics. Understanding the structure of the precious metal nanoparticles that make up these catalytic layers is often difficult due to the highly heterogeneous, disordered nature of these materials. This project will develop wide line solid state NMR of precious metal nuclei as a new characterisation tool for such nanoparticles. It will bring together a group with a long track record of developing new materials applications of solid state NMR and an internationally-leading industrial group that are developing fuel cell catalyst technologies. The project attempts to fulfil the philosophy of the Sainsbury Review to get the core academic science base interacting more directly with industry. Traditionally, platinum catalysts have been used exclusively for low temperature fuel cells due to their overall adequate activity and stability for three key reactions of interest. More recently, alloying of platinum with various other metals has shown improvements in both activity and selectivity leading to a diverse range of catalysts for specific reactions. Currently, more advanced research concepts are focussed on nano core-shell materials, where a platinum (or platinum alloy) shell is deposited onto a different core (e.g. palladium) to give both activity (through electronic modification) and cost benefits. Of the metals of interest, platinum is key as this is the basis for most current active formulations. Palladium is of increasing interest as recent reports have indicated that alloying palladium with base metals such as iron can increase activity for some reactions to that of platinum. Also, it has been extensively used as a core for platinum. Rhodium has not been extensively investigated for fuel cell catalysis, but it does show promise as a promoter for platinum for the electro-oxidation of ethanol. In addition, rhodium is the key catalytic metal for a large range of gas-phase reactions, including the CO-NOx reaction in automotive catalysis and the reforming of hydrocarbon fuels to give hydrogen. A characterisation approach that combines traditional analysis techniques (e.g. XRD, TEM, XPS) along with determination of the catalytic activity will be employed. This data will be merged with the new and potentially unique information that will be provided by solid state NMR. A fully multinuclear approach will be employed to examine 1H (to elucidate surface speciation and proton mobility, the latter via relaxation and pulsed field gradient measurements), as well as 13C and 27Al of the support materials. However the clear focus of the work here will be developing NMR of the metals directly. There has already been progress made on 195Pt which has shown that in such heterogeneous systems very broad spectral lines indeed can be encountered such that traditional pulsed approaches are not possible. With the use of field-sweep approaches accurate lineshapes of even very broad lines can be recorded. This project will take this philosophy, develop it further for 195Pt and take on the very much more challenging task of examining 103Rh and 105Pd. The reports of solid state NMR from the latter two nuclei are extremely scarce providing an indication of their difficulty. However by the use of the state of the art NMR equipment available (e.g. field sweep, very high magnetic field) and the construction of a probe optimised for the static observation of these nuclei it is anticipated that significant progress can be made in observing such nuclei. This would provide a new analytical probe of these technologically important materials.