Catalysis
Catalysts are an enabling technology that underpins the chemical industry.
Their deployment is so extensive that it is estimated that 90% of all chemical processes employ a catalyst, which in turn results in 35% of the global GDP being dependent on catalysis. Moreover, catalysis is a sustainability-driving technology.
While it is taught that a catalyst provides an alternative reaction route of lower activation energy and thus increases the rate of chemical reactions, in reality, this results in reduced energy consumption (from short processing times and/or low process temperatures). Thus, providing economic drivers, the original motivation for the deployment of catalysts, in parallel to environmental benefits, with the latter becoming ever more critical.
The UK and global drive toward net zero will be reliant on catalysis, with it widely accepted that only through the deployment of catalytic processes for chemicals, polymers and plastics, and fuel production will this ambitious target be achievable.
At The University of Manchester at Harwell, and in collaboration with our colleagues in Manchester and further afield, we are working on a range of activities that continue to develop systems for conventional applications of catalysis and aim to enable the upcoming transitions that are foreseen in the chemical industry, including alternative feedstocks, and the circular economy.
Projects
Projects include the deployment of alternative technologies spanning plasma, light and mechanochemical as modes of imparting energy to a catalytic process, novel feedstocks such as carbon dioxide, plastic waste, and lignocellulosic (non-edible) biomass, and sustainable utilisation of resources for catalysts production, for example, single-atom catalysis.
Across all activities, the national facilities at Harwell (Diamond Light Source, Central Laser Facility and ISIS Muon and Neutron Source) underpin this work, realising advancements in catalytic materials and processes that will enable further progression and innovation in the field. The proximity to these world-leading facilities at Harwell provides a unique collaborative environment, enabling direct access to cutting-edge analytical tools and facilitating close interactions with the beamlines’ scientists.
Applications of the facilities cover the elucidation of active species responsible for catalysis through spectroscopic techniques, mapping of the locations of active species within catalyst monoliths and fuel cells via combined imaging, spectroscopy, and diffraction, and assessing the diffusion of species within the porous frameworks that are ever prevalent within catalytic materials. This broad array of complementary studies is vital to understanding catalytic systems and the advancement of the field.
Areas of research
Principle investigator: Marta Falkowska
The importance of fluid behavior in confinement
Understanding how fluids behave at the molecular level when confined within porous materials is central to advancing heterogeneous catalysis and the design of functional materials. Confinement significantly alters fluid structure and interactions—impacting adsorption, reactivity, and transport—yet these effects remain challenging to probe experimentally.
Research objectives and approach
Our research addresses this gap by exploring how confinement changes molecular ordering and intermolecular interactions, using advanced neutron and X-ray scattering methods.
Focus on hydrogen bonding and molecular interactions
A key focus is on characterising hydrogen bonding networks and other interaction motifs (e.g. ionic and π–π interactions) in both bulk and confined environments. These systems range from pure liquids to binary and ternary mixtures, allowing us to systematically study solvent effects and the structural consequences of mixing under confinement.
By comparing the structure of confined fluids to their bulk counterparts, we build molecular-level insight relevant to catalysts, membranes, and sorbent materials.
Tools and techniques: Neutron scattering at ISIS
Total neutron scattering, particularly using the NIMROD instrument at the ISIS Neutron and Muon Source, plays a central role in this work due to its unique ability to probe both local and extended ordering in disordered materials.
Alongside experimental measurements, we contribute to developing workflows for:
- Sample preparation
- Data analysis (e.g. using EPSR and Dissolve)
- Best practices that lower the barrier to entry for researchers studying confined fluids.
Collaboration and expertise
Dr. Falkowska has a long-standing collaboration with ISIS scientists, having completed her PhD as the first ISIS Facility Development student based on site. This experience enabled her to participate in a wide range of neutron scattering experiments and to develop a deep understanding of technique capabilities.
Get in touch
If you’re considering using neutron scattering at ISIS but are unsure which technique is best suited to your system, feel free to get in touch — Marta is happy to help with experiment design or to guide you to the most appropriate method.
Principle investigator: Ines Lezcano-Gonzalez
The role of heterogeneous catalysis
Heterogeneous catalysis is fundamental to a wide range of industrial processes, playing a crucial role in energy production, chemicals manufacturing, and environmental sustainability. Advances in our understanding of the fundamental aspects of catalysts and catalytic processes, alongside developments in space- and time-resolved characterisation methods, are bringing us closer to the rational design of catalysts materials.
Despite these advances, the intricate structure and dynamic nature of catalysts under real reaction conditions continue to obscure our understanding of their true behaviour. Our research aims to address these challenges by developing detailed insights into catalytic processes, with a view to unlocking new pathways for clean energy, waste recycling and the development of greener technologies.
Real-time catalyst characterisation
A central component of our research involves the development and application of advanced characterisation techniques, focusing on operando methodologies that allow for real-time observation of catalyst behaviour under actual reaction conditions (Figure 1).
Using state-of-the-art X-ray and laser-based spectroscopies, in collaboration with world-class facilities like the Diamond Light Source and the Central Laser Facility, our research explores catalytically active centres, reaction mechanisms and deactivation pathways that are otherwise difficult to observe.
Understanding molecular processes to guide catalyst design
The work aims to unravel the underlying molecular processes of catalytic reactions, guiding the design of more efficient catalysts. By pushing the boundaries of characterisation, the goal is to develop a deeper understanding of catalytic systems, which will support the development of new technologies.
Current research focus areas
Current research projects focus on:
- Unravelling the reaction mechanism in methanol-to-hydrocarbons and propane dehydrogenation reactions
- The study and design of multifunctional catalyst materials for biomass-to-chemicals.
Principle investigator: Christopher Parlett
The role of biomass in sustainable chemistry
Renewable, sustainable biomass is widely accepted as a key chemical feedstock for the future, with its utilisation key to achieving net-zero emissions and the transition of the sector to a circular economy.
Catalytic cascades and multifunctional materials
Multi-step reactions represent a key step towards the utilisation of non-edible lignocellulosic biomass and its derivatisation into sustainable chemicals and fuels. While convention has typically dictated an approach of focusing on each single step discreetly, catalytic cascades, in which multiple steps are conducted at once, offer significant economic and environmental advantages. However, the development of multifunctional materials possessing two or more different active sites is critical to the exploitation of such processes.
Sustainability of catalysts: single-atom and cluster catalysis
Sustainability is not only limited to the process; consideration of the catalyst is also critical. Single-atom catalytic sites represent the ultimate in heterogeneous catalysis active site miniaturisation and, thus, efficient use of often scarce resources such as platinum group metals. Developing such systems for the selective transformation of biomass and derivatives from biomass links into the concept of cascade processes, and are developed hand-in-hand. However, shrinking the active site to an isolated atom may not result in optimal performance, with the size gap between single sites and conventional nanoparticle systems representing a materials challenge. Releasing optimal catalyst configuration requires materials to span systems comprising two-atom species up to clusters of tens of atoms. This size domain may well prove to be superior, especially in bimolecular reactions or where bimetallic species have displayed interesting synergies.
Waste as a chemical feedstock
Waste represents a complementary potential chemical feedstock, which, in the case of plastics, can be considered akin to biomass streams, with both requiring the breaking down of a polymeric structure. Moreover, plastic recycling is critical to realising a circular economy within the sector, which will aid in addressing this problematic waste by realising its inherent value.
Analytical techniques: operando X-ray spectroscopy
These independent but interwoven themes are underpinned through absorption and emission x-ray spectroscopy, including the development of novel reaction environments (figure 1) to enable operando investigations to elucidate:
- the nature of active catalytic species
- active site deactivation pathways and mechanisms
Projects
- Catalytic cascade reactions
Unlocking multi-step catalytic cascade reactions necessitates catalytic systems that can predictably drive a cascade so that each individual catalytic transformation occurs solely over the desired site. The spatial compartmentalisation of two different sites within a single porous structure (Figure 2) represents one strategy, with the power of such advanced materials demonstrated for oxidations and biofuel production. - Sub-nanometre active species
Sub-nanometre active species represent the efficient utilisation of global resources. While reactions on single-atom systems have shown promise, e.g. methane activation, further synthesis developments and on-stream stability assessments are paramount if these are to find industrial applications. Additionally, the potential advantages of diatomic and small cluster active species are still to be explored. - Plastic depolymerisation and recycling
Plastic depolymerising to monomers provides a pathway to waste valorisation. Polyethylene terephthalate (PET) conversion to dimethyl terephthalate represents a chemical route for recycling plastic bottles (and clothing). Returning PET to its monomers allows the production of recycled polymers identical to their virgin equivalents; however, efficient catalytic processes, ideally under mild conditions, require advanced catalysts.
Principle investigator: Shanshan Xu
What is plasma and how does it work?
Plasma is a (partially) ionised gas, created by applying (electrical) energy to a gas. This causes gas breakdown into ions and electrons. The light electrons are accelerated by the electric field, and they “activate” gas molecules, creating new ions, excited molecules and radicals.
This reactive chemical cocktail enable plasma to activate stable gas molecules (e.g. CH₄, N₂) into reactive species (e.g., radicals, excited molecules, and ions) which can trigger reactions at low temperatures.
The promise of nonthermal plasma catalysis
Nonthermal plasma catalysis is an attractive hybrid technology for many energy-intensive and kinetically and/or thermodynamically limited heterogeneous catalytic reactions.
My research aims to develop electrified nonthermal plasma catalysis processes to achieve sustainable chemical reactions such as:
- Hydrogen (H₂) production
- Nitrogen (N₂) fixation
- Carbon dioxide (CO₂) conversion
- Plastic waste recycling
These reactions are pursued under mild conditions, such as ambient temperature and atmospheric pressure, and utilise operando spectroscopy techniques to monitor these under real plasma conditions and gain an understanding of mechanism.
Catalyst engineering for plasma catalysis
This involves in the catalyst engineering and catalysis process.
For catalysts engineering, my research lies in designing and modification of porous materials, such as zeolite, metal-organic frameworks (MOFs), materials specific for nonthermal plasma catalysis system (Figure 1).
Spectroscopy techniques and collaboration
A broad range of spectroscopy techniques is employed to investigate:
- Catalytically active sites
- Reaction pathways
- Deactivation mechanisms.
These include:
- Infra-red (IR)
- DRIFTS
- UV-Vis
- X-ray spectroscopy such as XAS and XPDF.
This work is conducted in collaboration with world-leading facilities such as Diamond Light Source (Figure 2).
Research goals and vision
By pushing the boundaries of materials and plasma technology, the goal is to:
- Rationally design tailored catalysts for plasma catalysis
- Develop a deeper understanding of plasma catalysis systems.
Both are critical for advancing hybrid plasma-catalytic systems toward practical adoption.