CDT React - Available Projects - Intake 2023
Accelerating Net Zero Manufacturing with Intelligent Optical Reactor Technology
Supervisors: Dr Ceri Hammond, Dr Antonio Del Rio Chanona
Quickly transitioning to net zero manufacturing requires researchers to use modern methods for process discovery and development. This is especially true for the development of heterogeneously catalysed processes, which are still typically optimised by painstaking trial-and-error methods. As such, the overall objective of this project is to combine pioneering spectroscopy and reactor technology with machine learning and real-time optimisation to achieve self-optimising reactor technology applicable to the synthesis of important chemical products from biomass feedstock using heterogeneous catalysts.
We recently pioneered development of a novel heterogeneous catalyst reactor equipped with fiber optic technology. This reactor allowed us to follow the conversion of glucose to various bio-based chemicals of industrial interest using heterogeneous zeolite catalysts, at true continuous operational conditions and in real time, by performing operando optical spectroscopy. In particular, unique optical signals related to the active sites of the catalyst and all of the reaction pathways of the chemical process were identified, including the desired reaction pathway and those of undesired side reactions. Moreover, we could relate the intensity of each optical signal to the quantity of products formed, as verified by offline methods (HPLC and 1H-13C HSQC NMR), resulting in real time information of the performance of each catalyst in terms of activity, selectivity, and stability. As the reaction pathway signals are charge transfer bands associated with activation of the substrate by the catalyst (as opposed to chromophores of reactants and products), they also provide direct insight into the transition states of the various reaction pathways.
These breakthroughs are unprecedented in catalysis research, and represent the starting point for this project.This project will use this breakthrough to target the application of machine learning to heterogeneous catalysis and biomass conversion. In particular, we will combine fast data generation through operando optical technology with online learning algorithms to construct data-driven models in real-time through time series modelling. This will facilitate the development of ML algorithms that uniquely account for activity, selectivity and stability, at various operational conditions. We will validate this hypothesis, and then use the Intelligent Optical Reactor (IOR) technology to accelerate bio-based chemical manufacture by developing self-optimising reactor technology. In later stages, we will attempt to use the transition state insights provided by the reactor to generate advanced structureactivity relationships of relevance to future catalyst design.
Automated Discovery and Screening of Stimuli-Responsive Porous Liquids
Supervisors: Dr Becky Greenaway, Prof Matthew Fuchter, Prof Kim Jelfs
Porous liquids are an emerging class of porous materials that combine the properties of a microporous solid with the fluidity of a liquid. By incorporating intrinsic porosity in these liquids, properties that are difficult to achieve with conventional non-porous liquids are accessible, such as increased gas uptake and guest selectivity due to the presence of permanent tailorable pores. A range of porous liquids have now been reported, developed by translating porous solids into the liquid state, including porous organic cages (POCs), metal-organic cages (MOCs), covalent-organic frameworks (COFs), and metal-organic frameworks (MOFs). The gas capacity of these different porous liquids has been quite widely studied, with subsequent release of the gas relying on molecular displacement with liquid guests, pressure or temperature swings, or sonication. Recently, we reported the formation of high cavity concentration porous liquids using POCs – discrete molecules containing permanent molecular cavities accessible through windows – and demonstrated their ability to exhibit increased uptake of a range of gases (e.g., CO2, CH4, Xe, SF6) over neat liquids (Nature, 2015, 527, 216; Chem. Sci., 2017, 8, 2640; Angew. Chem. Int. Ed., 2020, 59, 7362; Adv. Funct. Mater., 2021, 31, 2106116). Despite these advances, the incorporation of stimuli-responsive porous materials into porous liquids, such as fluorescent or photoresponsive species, is much less investigated, but could offer additional advantages and/or use in different applications. For example, fluorescent porous liquids could be used as small molecule sensors, and photoresponsive liquids could enable controlled gas release using light. Recent proof-of-concept studies in the Greenaway group have proven that both types of these stimuli-responsive porous liquids are accessible, but the design and synthesis of both the initial porous material and subsequent porous liquid was time-consuming and the resultant material properties non-optimised. This project will build on these initial results, and our previous work on high-throughput POC synthesis and porous liquid discovery (Nature Commun., 2018, 9, 2849; Chem. Sci., 2019, 10, 9454), to screen and develop new stimuli-responsive porous liquids, followed by high-throughput screening of both their porous and optical properties (fluorescence, photoswitching).
Automated synthesis of nanoparticle libraries: a disruptive paradigm for particle discovery
Supervisors: Dr Yuval Elani, Dr James Wilton-Ely
The synthesis of nanoparticles is of major interest to a wide range of industries, including the pharmaceutical, fine chemicals, vaccine, chemical, food, biomedical and personal care sectors. Current approaches rely on one-by-one synthesis of different particle types based on rational design principles. In this project, we will establish a new paradigm based on high-throughput particle manufacture and discovery. We propose a pioneering microfluidic technology that will enable the automatic generation of vast nanoparticle libraries. This will allow us to synthesise hundreds of thousands of distinct particle types, with varied morphological, compositional and physico-chemical features. In doing so, we will lay the foundations of a new research area based on high-throughput particle discovery, and offer a drastic departure from existing approaches. We will use gold nanoparticles as a testbed to validate our system due to their tremendous potential in applications as varied as photothermal agents, delivery vehicles and platforms for catalysis, sensing and imaging. Building particle libraries and seeing how composition is related to architecture and particle properties will allow us to build a rule book which explains how composition, form, and function are intertwined.
Cell-free biocatalysis with enzyme-MOF composites
Supervisors: Dr Rob Davies, Prof Jason Hallett
Enzymes are naturally occurring catalysts which possess remarkably high activity and exquisite selectivity. As such they hold much promise as a new generation of industrial catalysts. However, the fragility of enzymes especially at higher temperatures and in non-native solvents can pose a key stumbling block for their successful deployment. In this project enzymes will be immobilized within a matrix (a Metal Organic Framework or MOF), leading to enhanced resistance against high temperatures and solvents, whilst still permitting easy substrate access to the enzyme active site and maintaining high activity. Novel MOF-enzyme constructs will be designed, prepared and characterized before their full evaluation (using high throughput methodology and kinetic profiling) in a number of industrially important processes key for future transition to a bio-based economy.
Data-driven spectroelectrochemistry of water oxidation electrocatalysis
Supervisors: Dr Aron Walsh, Prof James Durrant, Dr Reshma Rao
Water oxidation is the step limiting the efficiency of electrocatalytic hydrogen production from water. The development of sustainable catalysts is limited by the lack of understanding on the catalytic cycle.
Transient Absorption Spectroscopy (TAS) is a powerful tool to characterise the photophysical reactions of semiconducting materials. It measures the change in optical absorption of a material following a perturbation from the ground-state. While it is widely used for solar energy conversion, it is a new probe for electrochemical reactions. The spectra are challenging to interpret, and it can be difficult to separate intrinsic (bulk behaviour) from the extrinsic (defects, dopants and surfaces) effects.
This project will develop a toolkit for (i) the theoretical prediction of spectroelectrochemical signatures from quantum chemistry and (ii) advanced automated analysis of large experimental datasets that the student will be trained to collect. The project will involve reaction technology engineering over a multidimensional configurational space including materials composition, temperature, and electrochemical conditions. These developments will enable the extend the TAS method from qualitative kinetic analysis to quantitative insights into the in situ operation of state-of-the-art electrochemical systems for clean energy applications.
Dial a recyclable polymer
Supervisors: Dr Charles Romain, Prof Kim Jelfs
New technologies are urgently needed to develop truly sustainable materials, i.e. made from renewables, featuring useful properties while having end-of-life options (e.g. chemical recycling) that will contribute towards building our circular economy. Identifying and making such sustainable materials is challenging and it requires innovative strategies to access such “advanced” polymers. Whereas computational strategies to predict (co)polymers properties (e.g. glass transition temperature, Tg) are rapidly developing, the prediction of polymer “degradation” remains underexplored.
In this project, a combined experimental-computational approach making use of machine learning will be used to predict the chemical recyclability of polymers via estimation of thermodynamic parameters and by exploiting the ring-opening polymerisation (ROP) of cyclic monomers (e.g. lactones, cyclic carbonates, etc…). Ultimately, this project will contribute to guide towards the design of new monomers to enable polymer chemical recycling.
Expanding the photoswitch toolbox for light-addressable applications in catalysis, supramolecular chemistry and more.
Supervisors: Prof Matthew Fuchter, Prof Nick Long, Dr Becky Greenaway
Photoswitches are molecules that are capable of being reversibly interconverted between (at least) two states by light irradiation. The incorporation of photoswitches into multifunctional systems has huge relevance for next-generation light-addressable applications that span catalysis, biology and materials science. The Fuchter group have pioneered the development of heteroaromatic azo switches (J. Am. Chem. Soc. 2014, 136, 11878; J. Am. Chem. Soc. 2017, 139, 1261) and so far employed them in photopharmacology (J. Am. Chem. Soc. 2020, 142, 17457) and energy storage (J. Am. Chem. Soc. 2020, 142, 8688) applications. Despite the promise of existing switches however, there remains a number of challenges to be solved in the area of switch design – from completeness of switching to red-light switching, which are often determined by the application in question and therefore critical to address. It is non-intuitive to identify a new switch structure that meets all the performance requirements for a given application, with many established photoswitches falling short of what is needed. Coupled to this, there is a potentially huge design space to navigate when it comes to homing in on improved azo switch designs. This project will harness the power of both computational and experimental high throughout discovery to develop tailored high performance heteroaromatic photoswitches. We will then seek to showcase the switches developed in two light-addressable applications: lactide polymerisation catalysis and incorporation into switchable porous materials. This will demonstrate the power of high throughput approaches in this exciting area of research.
Harnessing reactive radical intermediates to design new and more sustainable catalysts
Supervisors: Dr Maxie Roessler, Dr Alex Ganose, Prof Klaus Hellgardt, Dr David Sale (Syngenta)
Film-electrochemical electron paramagnetic resonance spectroscopy (FE-EPR) is a transformative new experimental technique that enables detailed insight into catalytic reactions by detecting and interrogating unpaired electrons. In this project, we will (1) develop and design software and hence optimally harness information from FE-EPR, (2) engineer a user-friendly and widely applicable set-up, (3) design and screen novel working electrode materials and (4) apply FE-EPR to industrially relevant catalytic reactions, focussing on TEMPO-catalysed alcohol oxidation, Cu-catalysed radical rearrangements and organic radical intermediate formation, stability and characterisation.
Microfluidic encoding to accelerate autonomous exploration of high-dimensional chemical spaces
Supervisors: Dr Ali Salehi-Reyhani, Prof Klaus Hellgardt
There is a need to develop new experimental methods to better monitor, understand and optimize reactions and chemical systems, and to do so rapidly and scalably. The aim of this project is to develop a novel microfluidic platform that is able to accelerate the exploration and mapping of high dimensional chemical space for the optimization of reaction parameters. Traditionally, design of experiments is used to minimize the total number of experiments needed to find optima within any given reaction space. Liquid handling robots aided by online analytics are able to explore chemical space guided by ever sophisticated algorithms. Artificial intelligence based models show promise but have arisen in part due to our limited ability to efficiently map high dimensional chemical space at high resolution within reasonable timescales. Nevertheless, training datasets upon which machine learning relies are typically reported only for optimal synthesis reactions. This inevitably leads to inherent bias in machine-guided predictions. Therefore, robust datasets that span the entirety of a chemical space are necessary. Ultimately then, searching for new molecules is an inherently practical endeavour. Autonomous robotic platforms have been developed to help the modern chemist but tend to be batch reaction systems. They are intrinsically reliant on their starting conditions and this limits their capability to explore novel regions of parameter space. Flow based systems and online methods of reaction monitoring can overcome this and are capable of self guided exploration. However, they are fundamentally limited as single coordinate, point-based sampling approaches thus rely heavily on competent search strategies to efficiently explore parameter space. This limits flow chemistry to simple or low dimensional reaction schemes. The miniaturization of chemical reactors through microfluidic technology offers a promising opportunity for chemical synthesis. Low instantanteous volumes mean that reaction conditions can be screened rapidly in comparison with their robotic or conventional flow based counterparts. Yet, despite their capability, have not extended chemical synthesis in any fundamental way. In this project, we propose to develop a novel approach to chemical space mapping by spatially encoding planes of chemical parameter space onto the spatial plane of a microfluidic reaction chamber. By doing so billions of reaction conditions can be simultaneously established in parallel. It could exponentially speed up chemical data acquisition and pave the way to full and autonomous reaction space mapping on-chip and ultra efficient reaction optimization strategies.
Model-based experiment design to minimize material use in developing models of solvation
Supervisors: Dr Claire Adjiman, Prof Galindo Amparo, Prof Alan Armstrong
In liquid phase reactions and other liquid phase processes such as crystallization or liquid-liquid separation, solvation properties play a critical role as the choice of solvent can have an impact on reaction rate, affecting free energy barriers as well as the maximum concentration (solubility) that can be achieved, on regioselectivity or enantiomeric excess, and on partition coefficients, amongst many other factors. During the development of pharmaceutical or agrochemical processes, the identification of an appropriate solvent or solvent mixture can be a painstaking process and can require significant amounts of material to perform experiments in different media and at different conditions. The aim of this project is to effect a substantial reduction in the amount of material needed and in the time required to develop predictive models of solvation applicable to a particular substrate or reaction. We will achieve this by developing a novel model-based methodology to design high-throughput experiments (e.g., in a few solvents at different temperatures) with maximum information content so that the model can be developed successfully. We will apply this methodology to the prediction of solubility and selectivity. We will verify the predictive capabilities of the proposed models by conducting experimental campaigns in a larger set of solvents and we will refine the methodology on this basis.
Photo(electro)catalyst development for sustainable C-C coupling (funded by BASF)
Supervisors: Dr Salvador Eslava, Prof. Klaus Hellgardt, Dr Bernd Schaefer (BASF)
Classical chemical transformations are activated with heat, which is unspecific, energy-intensive, and can compromise yields for endothermal reactions. However, recent developments of photo-redox catalysis combined with state-of-the-art efficient LED-light sources and green electricity suggest that activation through photochemistry can be a sustainable alternative to thermally activated chemical transformations. Among chemical transformations, the coupling of carbon atoms is a great challenge, for example the combination of two methanol molecules to one molecule of mono-ethylene glycol (MEG). A photochemical pathway is supposedly following a radical mechanism that generates H2 as a valuable side-product.
This PhD project will aim at creating novel heterogeneous photo(electro)catalytic systems. This project will consider MEG-formation at first, but it will be open to mechanistic discoveries suggesting other valuable transformations. In a first step, inorganic semiconductor materials with an appropriate band-gap for the photo-oxidation reactions of interest will be synthesized for either photocatalytic reactors (powders) or photoelectrochemical cells (stack of films). Among different semiconductor candidates, halide perovskites will be considered due to their exceptional optoelectronic properties. The semiconductors will be combined with electrocatalysts to boost performance and selectivity and surrounded by charge transport layers for enhanced charge separation and yield.
This PhD project will be carried out in specialized labs in Applied Energy Materials at Imperial College South Kensington campus. This project is sponsored by BASF, a company that is interested in the industrial deployment of sustainable innovations and is a strategic partner of Imperial College. It will be embedded into an interdisciplinary team of professors and students within the EPSRC Centre for Doctoral Training in Next Generation Synthesis & Reaction Technology, pushing the boundaries of photocatalytic and photoelectrochemical chemistry toward industrial deployment. It will be co-advised by industrial experts from BASF and benefit from the competence of seven Imperial faculty members convening in bi-weekly co-creation meetings.
Applications are invited for the above project, and the successful applicant will undertake the EPSRC CDT (rEaCt) programme, as part of Cohort 5 (Intake 2023).
Please note that the BASF studentship projects follow the same programme as the normal CDT studentships. The difference is that project funding comes from BASF and not EPSRC.
The project is one of a number of BASF funded projects in the area of photochemistry within the CDT, which, in turn, forms part of a wider suite of activities that BASF is supporting within the CDT, all of which follow the principles detailed below.
Objective: BASF, the world’s leading chemical company, wishes to explore the application of flow chemistry in its R&D workflow for the synthesis of novel agrochemicals, and commodities. In this project, it will assemble a multidisciplinary team of scientists and engineers to explore the value of synergies between a variety of cutting-edge technologies, to develop more effective and efficient chemical production processes.
Setup: This project will bring together a group of highly motivated graduate students to work on two representative challenges from industrial process development, where photochemistry in combination with flow chemistry methodologies will be integrated holistically with in-line screening and analytics, and chemical process engineering complemented by machine learning and modelling. The members of this interdisciplinary project team will be exposed to a broad range of competencies and interact closely with each other in working on a disruptive change of the R&D workflow in a large chemical enterprise.
Training: Industrial R&D scientists based at BASF’s site in Ludwigshafen, the largest chemical “Verbund”site in Europe, will be closely involved in the programme, combining a real-world industrial experience with cutting-edge academic research. Each of the students will be advised by an internationally renowned professor and a BASF scientist and will be part of a centre for doctoral training, bringing together fellow graduate students in closely related fields of research and building a deep understanding of the area of specialization.
This project forms part of a wider suite of activities that BASF is supporting within the CDT. The successful candidate will be able to interact with, and leverage the benefits of, this wider activity. There will be opportunities for placement(s) (total of up to one year duration) within the BASF organisation during the studentship period.
The Computerized Chemist: Building an automated microfluidic reactor for the optimization of challenging organic transformations
Supervisors: Dr Chris Rowlands, Prof Chris Braddock
This project combines a new automated microfluidic reaction platform with relay cross metathesis (‘ReXM’), a cutting-edge but sensitive and unoptimized synthetic route to biochemically-useful terpenoids, which are a class of compounds accounting for ~60% of all known natural products. The automated reaction platform consists of a computer-controlled valve and heater array, and by actuating these, the chip can be reconfigured to mimic any other microreactor, allowing the reaction conditions (temperature, reaction time, stoichiometry, etc.) to be altered as desired. In this project, the chip will be used to automatically optimize ReXM, producing a powerful method for
producing arbitrary turpenoids. Ultimately this combination of automated optimization and synthetic utility will yield
a ‘dial-a-terpenoid’ system, where the desired reaction is optimized on-the-fly to yield the desired product.
Using water and electrons for green and sustainable reduction of C-O bonds.
Supervisors: Prof Klaus Hellgardt, Prof Mimi Hii
As we switch from petrochemical (mainly hydrocarbons) to bio-renewable (mainly oxygenated) feedstocks, safer and efficient methods to convert C-O bonds to C-H bonds will be an important part of the strategy towards a more sustainable future. While a number of electrochemical reactors have become commercially available in recent years, they are generally built for synthesis/reaction discovery, and are not designed for obtaining reaction data and understanding. In a previous project, we have constructed an electrochemical flow reactor that can be used to reduced amide bonds - one of the most stable C=O bonds found in nature.
In this project, we will aim to extend this to the reduction of other types of C=O compounds (aldehydes, ketones, acids and esters) using a data-guided approach.