Novel polymers of intrinsic microporosity for heterogeneous base-catalysed reactions (HBC-PIMs)

Lead Research Organisation: Swansea University
Department Name: College of Science

Abstract

Catalysts play a crucial role in chemistry, as they increase the rate of reaction by lowering the activation energy, allowing the formation of compounds that otherwise will not form promptly. Typical examples are the production of ammonia, which is a process that needs to be catalysed by iron, or the production of biofuels. The improvements of catalytic processes not only help chemists and engineers to increase the efficiency of reactions, but also to reduce waste products, generating a massive environmental impact. This is especially true if we can design and synthesise new catalysts that produce alternative fuels in a more efficient way. This will be beneficial from both the economic and the social point of view, as we can reduce the cost of sustainable fuels and, at the same time, the exploitation of natural resources such as fossil fuel.
The two most common catalysed reactions are known as homogeneous, where the catalyst can be dissolved in the media, and heterogeneous, where it is insoluble. Homogeneous catalysts are sometimes more active but their separation and reutilisation requires more energy and effort, whereas the heterogeneous ones are easily removed and recycled from the reaction by simple filtration. They can be further classified as acid, neutral or basic (alkaline), according to the nature of their active sites (i.e. where the catalytic reaction happens). Although alkaline catalysed reactions have been less investigated than their acidic counterparts, in recent years they have become more attractive as they are suited for the efficient production of biodiesel, as a sustainable and renewable source of fuel.
This research project will focus on the design and synthesis of novel basic heterogeneous catalysts based on Polymers of Intrinsic Microporosity (PIMs). PIMs are materials with porosity arising from the inefficient packing of their polymeric structure in the solid state, which leaves voids of nano-dimensions. They can be used for a wide range of applications, including gas separation, gas storage and catalysis. Porosity represents a great advantage for a heterogeneous catalyst, as it forces the reaction to occur in a close environment, such as the surface of a pore, forcing the components of the reaction to be in much closer contact. Because of this advantage, PIMs have been previously used in heterogeneous catalysis but only by incorporating in the material active metal ions, which is not ideal as the presence of the metal makes them more expensive and less environmentally friendly. Recently, I introduced and patented a new class of PIMs based on a core known as Tröger's base (TB). They combine the high porosity of PIMs with the presence of two basic (alkaline) nitrogens. Attempts have been made to use TB cores by grafting them into pre-made polymeric materials, but this procedure leads to loss of catalytic material (known as leaching) during its recycling from the reaction media. I recently reported the synthesis of a network (insoluble) PIM exclusively made exclusively via TB formation, which showed great potential for heterogeneous catalysis, especially because the active site (TB) is an integral part of the material, and not simply grafted onto it. The project aims to the synthesis of new TB-PIMs to be used to catalyse biomass conversion (i.e., from waste biomass to make sustainable fuels) along with other environmentally and commercially important reactions. The improved production of biodiesel is not the only significant reaction where these novel polymers can be employed. The polymers will also be tested for the conversion of by-product created during the biodiesel synthesis into more reactive compounds, and for the conversion of CO2 into more useful products. Last but not the least, the polymers can be further turned into new materials for more efficient anion-exchange resins, a class of materials that can be used for purification of water and removal toxic metal from liquid waste.

Planned Impact

The project will generate advanced materials to be used as catalysts for commercially and environmentally important reactions.

Scientific impact: since the catalysis field is always very active, the synthesis of new materials is expected to have a great impact in the scientific community, especially if they cover a relatively unexplored area. A major aim of this proposal is also to provide direct training to a PDRA and a PhD student whose contribution is crucial for the success of the project. The scientific knowledge and experience gained will make them highly competitive in the job market.

Socio-economic impact: It is estimated that the human population will reach 9 billion people by 2050 and to keep up with the economic growth we will require 50% more fuel. At the same time, a cut of CO2 emissions by up to 80% is required to preserve political, social, fuel and climate security. The general public is well aware that the search for more efficient ways to produce sustainable fuels is extremely important, as we are rapidly exploiting the natural resources and the prices of fossil fuels can only rise. From the social point of view, this will go well beyond the mere reduction of fuel prices, as the preparation of new catalysts designed to improve pre-existing protocols will also help to reduce the amount of waste and the gas emission. It is easy to imagine that this would have a considerable environmental impact, improving the well-being and quality of life.

Industrial and economic impact: The newly implemented (15th April 2018) Renewable Transport Fuel Obligation (RTFO) compels the reduction of regular diesel use, and the doubling of biodiesel use by 2020. It is estimated that catalysis currently contribute over £50 billion/year to the UK economy. The production of better and faster catalysts will therefore be highly valued by the industrial sector, as reducing the reaction times leads to the reduction of the production costs, which is strongly beneficial for both the industry and the general public (i.e., by decreasing the prices of fuels). This project is, for that reason, likely to boost the creation of new jobs in both R&D and manufacturing.

Skills, interdisciplinary research training and public engagement: The innovative design of the proposed materials, where the basic catalytic centre is part of the polymers and not simply grafted onto a pre-existing support, not only aims to improve existing catalytic protocols, but also to spark the creativity of researchers from both industry and academia, who can try to use the same concept in their protocols, leading to further development of the field. The PDRA and PhD student involved in this project will have the chance to work in close contact with experts from other institutions, receiving state-of-the-art training that links complementary fields and allows them to expand their knowledge and skills. The renewable energy and environment-based topic of this proposal may also be of interest to the general public because of its significant impact on lifestyle and economy, for instance by showing them that our cutting-edge research will lead to a decrease of the fuel prices, and knowing that we are constantly working on tackling environmental issues such as the reduction of the use and dependence from fossil fuels. The project will use different methods for the dissemination of the obtained results, including speaking at international conferences, in public events such as Science Festivals and visiting schools, and exploiting my role of STEM Ambassador, as it is essential to teach young generations about the benefit of living in a more sustainable world.

Publications

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Description The aim of this project is to prepare new polymers that act as heterogeneous catalysts, aimed to improve some of the current protocols, making the conversion of raw material into added valued ones in a cheaper and faster way. As we promised, we have already synthesised and characterised a number of new polymers that improve the current state-of-the-art for heterogeneous catalysis, for several based-catalysed reactions. The new polymers possess tunable porosity, so that we can use them with a larger variety of reagents, which was not possible with other similar materials. The new findings will be published in a series of scientific articles, the first ones starting in 2021. In addition, with current and new collaborations, we are expanding the aim and purpose of this project, relating our materials to other valuable catalytic systems, which are going to be improved with our system. This further confirms and improves the multidisciplinarity of our project.
Exploitation Route The full characterisation of these polymers and their adaptability to current systems, will allow other researchers form both academia and the industry, to use our approach and materials for their reactions. We especially aim to convince the industry to use our metal-free, more eco-friendly and sustainable materials, for important applications.
We aim to synthesise many more polymers, to adapt them to even newer applications, and to further improve the current ones.
Sectors Chemicals,Education,Energy,Environment,Other

 
Description With Dr Elena Tocci and DR Aleassio Fuoco: Advanced studies for the preparation of sustainable fuels: from molecular modelling to the synthesis of novel polymers of intrinsic microporosity 
Organisation National Research Council
Department Institute on Membrane Technology
Country Italy 
Sector Academic/University 
PI Contribution My group provided the design of the porous polymers that the partners used for the computational modelling. We have regular meeting with our partners, to improve the knowledge exchange and to enhance the results and outcomes
Collaborator Contribution My partners provided a series of computational models that will provide great insight for the evaluation and explanation of the materials performance. This work is especially aimed at the understanding of the the structural proerties of the materials produced within this project. This understanding not only will give a great added value for future publications, but also will help us with the design of future polymers.
Impact The ITM team provided a series of computational models aimed to understand the porosity of the materials and how to tune it for important applications, as anticipated in the grant proposal. It is a very multidisciplinary work, as we provided the design and synthesis of the polymers and the ITM team helped us with the modelling and evaluation/assessment of the fnal properties, both from the theorethical chemistry point of view and from the engineering one, which is not in my comfort zone, hence the request for help.
Start Year 2019
 
Description With Dr Manuel Iglesias-Alonso from the University of Zaragoza 
Organisation University of Zaragoza
Country Spain 
Sector Academic/University 
PI Contribution The nature of our polymeric catalysts allow us to link metal based compounds. We planned to embed some of Dr Manuel Iglesias-Alonso metal catalysts into our polymers. In this way we can use the same system (with or without metals) to either reuse wasted CO2 converting into a hydrogen carrier, or to release hydrogen from formic acid to provide a safe hydrogen supply.
Collaborator Contribution Dr Manuel Iglesias-Alonso is an expert inorganic chemist. Recently, he started developing and improving a series of inorganic catalysts aimed to dehydrogenate formic acid into hydrogen and CO2. Our polymeric catalysts can do the opposite, combining hydrogen and CO2 to create formic acid, and use it as a safe hydrogen carrier. Dr Manuel Iglesias-Alonso is going to test some of our best polymers in combination to his compounds. To speed up the collaboration one of Manuel's PhD students will be coming to Swansea University to test some of their cataysts in combination to our polymers. This should happen via a previously agreed and already funded Erasmus + travel funding.
Impact This partnership is supposed to link organic, inorganic and material chemistry.
Start Year 2020
 
Description With Prof Jose Lopez-Sanchez from the University of Liverpool 
Organisation University of Liverpool
Country United Kingdom 
Sector Academic/University 
PI Contribution Some of our best polymeric catalysts are going to be tested in Liverpool at the MicroBioRefinery of which Prof Jose Lopez-Sanchez is the director.
Collaborator Contribution The polymer sent to Prof Jose Lopez-Sanchez at the MicroBioRefinery will be tested for commercially important catalyses, including the potential production of biodiesel. Prof Jose Lopez-Sanchez kindly agreed to test our polymers for free, for the purpose of enhancing this collaboration.
Impact The collaboration is supposed to link academia and industry, with a focus on chemical engineering too.
Start Year 2020
 
Description Invited Keynote speaker at: International Congress on Membranes & Membrane Processes 2020 Online - Live and on-demand | 7-11 December 2020 GMT (ICOM 2020) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact I was selected as Keynote speaker for ICOM 2020, which is one of the most important international conferences for membranes. In my talk I discussed the outcome of some recent fundings also related to the current award and the polymers created from it. It was an online "live" conference and the audience was very braod, from peeers, to students, to industry delegates etc.
I received several questions during the Q/A session and I was asked to prepare an invited paper for a special issue related to this conference to an important journal.
EPSRC was acknoledged for this talk.
Year(s) Of Engagement Activity 2020
URL http://www.icom2020.co.uk/
 
Description Invited speaker at the international conference: The First International Conference on "Green" Polymer Materials 2020 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact I was invited by the organisers as a keynote speaker for this first online international conference on Green Polymeric Materials. The talk was aimed to a broad audience and I discussed my recent achievement on the synthesis and characterisation of more sustainable polymeric materials, which is one of the main topics of the awards.
It was a very interesting experience as it was my first completely online talk. EPSRC was acknowledged for this talk.
Year(s) Of Engagement Activity 2020
URL https://cgpm2020.sciforum.net/
 
Description RSC Materials Chemistry Division poster symposium 2021 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact In this event organised by the RSC Natasha Hawkins presented a poster and a flash presentation, aimed to PGRs and supervisors. The entire work revolved around the EPSRC project and showed our preliminary results, which are going to be published later on. It was an online event because of the Covid19 situation, but it was nevertheless an exiting venue.
Year(s) Of Engagement Activity 2021
URL https://www.rsc.org/events/detail/44533/rsc-materials-chemistry-division-poster-symposium