Catch and Release: Recycling of Homogenous Metal Catalysts Using Aromatic Tags and Electroactive Nanocarbon Foams
Lead Research Organisation:
University of Leeds
Department Name: Sch of Chemistry
Abstract
Homogeneous precious metal catalysts constitute the most versatile catalysts in the chemical and pharmaceutical sectors, enabling manufacture of high-value chemicals at high productivity and lower energy consumptions. However, high costs, limited supply, toxicity and strict regulations create an essential need to recover and re-use precious metal catalysts. This interdisciplinary project will develop a generic Catch-and-Release recovery technology for homogeneous precious metal catalysts to overcome the limitations of existing catalyst recovery/scavenging strategies. This technology will be based on the modification of known metal complex catalysts with aromatic 'catch' units and the use of electroactive nanocarbon foams to enable induced catalyst 'release'.
Specifically, three commercially-important model catalysts (Ru, Ir, Pd) will be modified with aromatic tags to enable non-covalent catalyst sorption into nanocarbon foams. The high affinity between graphitic foam surface and the aromatic tags will allow for highly selective catalyst removal from different reaction mixtures ('Catch'). In addition, the use of electrically conducting nanocarbon foams as sorbents will enable to induce/tune the desorption of the recovered catalysts back into solution ('Release') through electric-thermal stimuli. The Catalyst Catch-and Release systems will be tested, characterised and optimised for three important model reaction systems (Ru: transfer-hydrogenation, Ir: hydrogen borrowing reactions, Pd: oxidation of bio-feedstock). Catalyst Catch-and-Release efficiencies as well as underpinning structure-property relationships will be studied in flow, a chemical processing mode of increasing commercial importance. Materials characterisation and performance data across the three catalyst systems will provide a deeper understanding of the Catch-and-Release process and provide detailed specification data for future technology development. Collaboration with the industrial project partner William Blythe Ltd (a UK manufacturer of nanoarbons) will ensure commercial viability of the newly developed Catch-and-Release nanocarbon-foam sorbents.
The project will deliver the following critical outputs: (i) well-characterised Ru-, Ir- and Pd-catalysts tethered to (electrochemically-active) aromatic moieties, (ii) Catch-and-Release catalyst sorbents based on electro-responsive nanocarbon-foams (iii) Catch-and-Release structure-property relationships to enable technology extension to other catalyst systems; (iv) techno-economic performance data to underpin industry engagement. These outputs will have transformative impacts by developing a novel catalyst Catch and Release concept that is applicable across a wide range of reaction systems and offers great control, thereby enabling wider and more sustainable utilisation of sophisticated homogeneous catalysts.
Specifically, three commercially-important model catalysts (Ru, Ir, Pd) will be modified with aromatic tags to enable non-covalent catalyst sorption into nanocarbon foams. The high affinity between graphitic foam surface and the aromatic tags will allow for highly selective catalyst removal from different reaction mixtures ('Catch'). In addition, the use of electrically conducting nanocarbon foams as sorbents will enable to induce/tune the desorption of the recovered catalysts back into solution ('Release') through electric-thermal stimuli. The Catalyst Catch-and Release systems will be tested, characterised and optimised for three important model reaction systems (Ru: transfer-hydrogenation, Ir: hydrogen borrowing reactions, Pd: oxidation of bio-feedstock). Catalyst Catch-and-Release efficiencies as well as underpinning structure-property relationships will be studied in flow, a chemical processing mode of increasing commercial importance. Materials characterisation and performance data across the three catalyst systems will provide a deeper understanding of the Catch-and-Release process and provide detailed specification data for future technology development. Collaboration with the industrial project partner William Blythe Ltd (a UK manufacturer of nanoarbons) will ensure commercial viability of the newly developed Catch-and-Release nanocarbon-foam sorbents.
The project will deliver the following critical outputs: (i) well-characterised Ru-, Ir- and Pd-catalysts tethered to (electrochemically-active) aromatic moieties, (ii) Catch-and-Release catalyst sorbents based on electro-responsive nanocarbon-foams (iii) Catch-and-Release structure-property relationships to enable technology extension to other catalyst systems; (iv) techno-economic performance data to underpin industry engagement. These outputs will have transformative impacts by developing a novel catalyst Catch and Release concept that is applicable across a wide range of reaction systems and offers great control, thereby enabling wider and more sustainable utilisation of sophisticated homogeneous catalysts.
Planned Impact
Direct economic impact is anticipated on chemical/pharmaceutical manufacturing as well as on sectors related to nanocarbon manufacture and nanotechnology development.
In chemical manufacture, the developed Catch-and-Release technology has transformative potential by promoting a much wider adoption of homogeneous catalysts in industry. This would allow to harvest the sophistication molecular catalysts (efficiency, selectivity, tuneablity) across a wider range of chemical reaction systems in the fine-chemical/pharma industries, eventually leading to the manufacture of existing (and completely new) high value chemicals at lower cost, higher productivity and smaller environmental impact. To show-case the broad applicability to real-life catalyst systems, the project will collect techno-economic performance data for three existing 'off-the-shelf' metal complex catalysts. The availability of a robust, generic catalyst recycling technology will also boost wider technological adoption of new molecular catalysts based on metal (Cu, Rh, Fe etc) with significantly lower cost, more secure supply, lower toxicity and lower environmental food-print. The technology is also likely impact on completely different high-value catalyst systems such as enzymes, crucial for the valorisation of renewable bio-feedstocks.
For the nanocarbon sector, the utilisation of foams as catch-and-release adsorbents adds a completely new route for the commercial exploitation of nanocarbons. In the short to medium term, the project will demonstrate a new application of nanocarbon foams in chemical manufacture, linking nanocarbon manufacture to a new, potentially high-volume customer base. The potential for real-world impact is highlighted by the involvement of the commercial project partner, William Blythe Ltd, a materials manufacturer who will ensure that the development of the catch-and-release nanocarbon foams is well aligned with economic and technological requirements in nanocarbon manufacture. In the long term, the project will advance the fundamental understanding of carbon nanostructure 3D networks, laying an important foundation for future innovations, e.g. in biosensing, structural composites or energy storage.
The project will provide prototype materials and detailed materials/process specifications to engage commercial stakeholders, including in high value chemical manufacturing (e.g. AstraZeneca, GSK, Johnson Matthey, Croda, CatSci, Phosphonics), nanocarbon manufacture (e.g. Applied Graphene Materials, Thomas Swan), and reactor technology (e.g. Flowid, Asynt). In the long term, it is envisioned to develop the Catch-and-Release nanocarbon foams to technological maturity through direct input from these partners. Advancing technological maturity of nanocarbon foams will also stimulate commercial innovation in other nanotechnology sectors with interests in porous nanocarbon networks (energy storage, membranes, actuators), contributing to the UK economic competitiveness in the field of innovative nanocarbon-based products and technologies.
The general public could eventually benefit from value-added end-products and the potential economic advantages associated with them. Most directly, the public could benefit from the manufacture of high value chemicals and drugs at considerably lower energy cost and environmental impact. In the long term, other innovative products are likely to emerge through improved understanding of nanocarbon foams, especially in flow-related applications, e.g. new separation and water treatment techniques, new technologies for sustainable energy production or sensitive electrochemical sensors.
In chemical manufacture, the developed Catch-and-Release technology has transformative potential by promoting a much wider adoption of homogeneous catalysts in industry. This would allow to harvest the sophistication molecular catalysts (efficiency, selectivity, tuneablity) across a wider range of chemical reaction systems in the fine-chemical/pharma industries, eventually leading to the manufacture of existing (and completely new) high value chemicals at lower cost, higher productivity and smaller environmental impact. To show-case the broad applicability to real-life catalyst systems, the project will collect techno-economic performance data for three existing 'off-the-shelf' metal complex catalysts. The availability of a robust, generic catalyst recycling technology will also boost wider technological adoption of new molecular catalysts based on metal (Cu, Rh, Fe etc) with significantly lower cost, more secure supply, lower toxicity and lower environmental food-print. The technology is also likely impact on completely different high-value catalyst systems such as enzymes, crucial for the valorisation of renewable bio-feedstocks.
For the nanocarbon sector, the utilisation of foams as catch-and-release adsorbents adds a completely new route for the commercial exploitation of nanocarbons. In the short to medium term, the project will demonstrate a new application of nanocarbon foams in chemical manufacture, linking nanocarbon manufacture to a new, potentially high-volume customer base. The potential for real-world impact is highlighted by the involvement of the commercial project partner, William Blythe Ltd, a materials manufacturer who will ensure that the development of the catch-and-release nanocarbon foams is well aligned with economic and technological requirements in nanocarbon manufacture. In the long term, the project will advance the fundamental understanding of carbon nanostructure 3D networks, laying an important foundation for future innovations, e.g. in biosensing, structural composites or energy storage.
The project will provide prototype materials and detailed materials/process specifications to engage commercial stakeholders, including in high value chemical manufacturing (e.g. AstraZeneca, GSK, Johnson Matthey, Croda, CatSci, Phosphonics), nanocarbon manufacture (e.g. Applied Graphene Materials, Thomas Swan), and reactor technology (e.g. Flowid, Asynt). In the long term, it is envisioned to develop the Catch-and-Release nanocarbon foams to technological maturity through direct input from these partners. Advancing technological maturity of nanocarbon foams will also stimulate commercial innovation in other nanotechnology sectors with interests in porous nanocarbon networks (energy storage, membranes, actuators), contributing to the UK economic competitiveness in the field of innovative nanocarbon-based products and technologies.
The general public could eventually benefit from value-added end-products and the potential economic advantages associated with them. Most directly, the public could benefit from the manufacture of high value chemicals and drugs at considerably lower energy cost and environmental impact. In the long term, other innovative products are likely to emerge through improved understanding of nanocarbon foams, especially in flow-related applications, e.g. new separation and water treatment techniques, new technologies for sustainable energy production or sensitive electrochemical sensors.
Publications
Mannering J
(2021)
Engineering of Microcage Carbon Nanotube Architectures with Decoupled Multimodal Porosity and Amplified Catalytic Performance.
in Advanced materials (Deerfield Beach, Fla.)
Xia D
(2022)
Compressive and thermally stable boron nitride aerogels as multifunctional sorbents.
in Dalton transactions (Cambridge, England : 2003)
Xia D
(2020)
Electrically Heatable Graphene Aerogels as Nanoparticle Supports in Adsorptive Desulfurization and High-Pressure CO 2 Capture
in Advanced Functional Materials
Xia D
(2021)
Facile Synthesis of Electrically Conductive and Heatable Nanoparticle/Nanocarbon Hybrid Aerogels
in ACS Applied Materials & Interfaces
Xia D
(2020)
Tuning the Electrical and Solar Thermal Heating Efficiencies of Nanocarbon Aerogels
in Chemistry of Materials
Xia D
(2022)
Recent progress of Bi-based electrocatalysts for electrocatalytic CO2 reduction.
in Nanoscale
| Description | The award is still active and research is currently in its final and therefore key phase. The main grant findings will be clearer for the next ResearchFish submission. So far, key achievements include: - New fabrication route for graphene-based foams developed in collaboration with industry partner, allowing for systematic tuning of internal foam microstructure and surface chemistry - Scalable chemical foam functionalisation methodology developed, based on through-flow foam impregnation, allowing for 3D-uniform foam functionalisation with a broad range of homogeneous and heterogeneous catalysts - Development of a chemical flow reactor with integrated functional graphene-foam component, enabling graphene foam exploitation in continuous flow processes as well as in-situ electrical foam stimulation - Demonstration of functionalised graphene foams as effective and versatile through-flow catalysts and sorbents in flow-chemical processes |
| Exploitation Route | The research findings contribute to knowledge in catalysis, materials science and chemical process engineering. The newly developed foam functionalisation approach provides highly interesting and well-controlled through-flow catalyst systems, for pharmaceutical and fine-chemical applications. In materials and nanocarbon science, the findings provide a deeper understanding of the interdependence of nanocarbon foam microstructure and chemical nanocarbon properties, which will benefit important established nanocarbon research fields, such as energy storage materials, sensing, water treatment, and separation technologies. In addition the investigation of nanocarbon foams in flow provides a versatile new tool to investigate fundamental properties of porous nanocarbon assemblies. Flow investigations of nanocarbon foams bearing immobilised homogeneous catalysts can be extended to study functional properties of other surface-bound functional molecules (enzymes, functional polymers etc). The integration of nanocarbon foams into a fully functional flow set-up will stimulate new work in porous materials research as well as process engineering. The existing flow reactor set-up can be progressively adapted, e.g. by integrating high pressure/temperature or pulsatile flow with a view to explore more complex hydrothermal or multiphasic flow reaction systems in the future. The availability of robust nanocarbon foams with controlled microstructure and surface chemistry provides interesting new model systems for advancing the understanding of 3D porous materials both on a fundamental level (e.g. providing experimental data for fluid dynamics simulations) and for more applied investigations (e.g. development of new flow reactor technologies). |
| Sectors | Chemicals,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology |
| Description | Industry Collaboration with William Blythe Ltd |
| Organisation | William Blythe Ltd |
| Country | United Kingdom |
| Sector | Private |
| PI Contribution | The industrial collaboration with William Blythe is covered by an NDA, and therefore no specific inputs can be detailed. The general contribution from the research team centres on insights into the processing of certain commercial materials, and academic exploration of new application fields for certain materials. |
| Collaborator Contribution | The industrial collaboration with William Blythe is covered by an NDA, and therefore no specifics on in-kind contributions can be given. Contributions by the commercial partner includes generous provision of key raw materials free of charge (both commercial and in-house research materials), ensuring cost-effectiveness of the research, allowing for scale-up investigations, and ensuring economic relevance of the academic research. |
| Impact | Specific outputs covered by NDA. More generally, the project has helped to cement the research relationship between the commercial partner and the academic investigators at Leeds University, with the industrial partner providing support (incl substantial in-kind support) for another EPSRC grant proposal in the materials science area to be submitted in March 2023. |
| Start Year | 2020 |