GCRF START funds strategic Energy Materials Workshop

Cape Town, 16-17 December 2019

A warm South African welcome and stunning Cape Town backdrop greeted the 20 participants of the GCRF START Energy Materials Workshop, which was funded by GCRF START. The event took place from the 16-17 December 2019 and was hosted by the Catalysis Institute and c*change (DSI-NRF Centre of Excellence in Catalysis) at the University of Cape Town in South Africa.

The event kicked off with an introductory dinner at the stunning Steenberg Farm. Nationalities from Swaziland and South Africa through to the UK and Germany were represented. The Post-docs (PDRA’s), MSc. and PhD students, University lecturers, Principal Investigators (PI’s) and Co-Investigators (Co-I’s), Communications and grant staff hailed from the University of Cape Town’s Catalysis Institute (SA), University of the Witwatersrand (SA) Diamond Light Source (UK), the ISIS Neutron Source (UK), the University of Oxford (UK), Cardiff Catalysis Institute, Cardiff University (UK), the University of Southampton (UK), University of Sheffield (UK), The African Neutron and Synchrotron Data Analysis Competency (ANSDAC), and the DST-NRF Centre of Excellence in Catalysis – c*change (SA).

GCRF START December 2019 Energy Materials Workshop participants at the University of Cape Town workshop venue. Front row from left: Dr Daniel Bowron, Sikhumbuzo MasinaDr Sofia Moreno-Diaz, Dr Caren Billing, Chris Mullins, Adam Shnier; Second row from left: Mathias Kiefer, Dr Michael Higham, Dr Peter Wells, Prof. Moritz Riede, Prof. Michael Claeys; third row from left: Dr Wilson Mogodi, Dr Thomas Derrien; back row from left: Dr Mohamed Fadlalla, Dr Nico Fischer, Dr Pascal Kaienburg, Prof. Chris Nicklin, Prof. Dave Billing. Photo Credit Rebekka Stredwick, ©Diamond Light Source 

Tours of the Centre for Catalysis were given by Professor Claeys showcasing the excellent laboratory facilities and equipment available for use. GCRF START project Investigators and PDRA’s presented research covering topics including:     

  • Photo Voltaic’s – PV, batteries, fuel cells, solar cells
  • Organic solar cells and Microstructures
  • Organic semiconductors
  • Global optimisation of Cu clusters
  • Catalysis (controlling nanomaterials and structures)
  • CO2 hydrogenation
  • X-ray Spectroscopy
  • Crystallography

Presentations by Nico Fischer at ANSDAC, Michael Claeys from c*Change, and Daniel Bowron from the ISIS Neutron Source, provided insights into the collaboration opportunities through GCRF START.

Passing the mid-point of the GCRF grant is a good time to reflect on what has been achieved thus far, and is a useful time to plan ahead – both within the time of the remaining grant and how to continue the momentum into the future. With established PI’s, Co-I’s, and Post-docs attending the workshop, there was ample opportunity to share ideas for a potential GCRF START phase II, and to agree a vision and strategy for forging new ways to collaborate on the African continent in keeping with the UN Sustainable Development Goals and Pan-African 50-year mission – AGENDA 2063.

In particular, the discussion considered ways to facilitate beamtime applications within Energy Materials research. Access to Diamond can either be through an individual proposal, or through a ‘Block Allocation Group’ (BAG). GCRF START is an excellent vehicle to bring together a BAG for Energy Materials research, which also increases the networking between scientists.  Indeed, there is already a successful BAG access in Structural Biology. In addition, beamlines with robotic support allow for remote access, meaning scientists can take control of the beamline without having to travel thousands of miles to take part.

Another key point was how to increase the amount of outreach activity we do to further the impact of the grant and help foster an enthusiasm for salient science within the local population.  There are already many examples of excellent practice from individuals and institutions within the grant network such as SciArt with local crafters from the Keiskamma Art Project, as well as outreach to schools and graduates through to government ministers.

Finally, the network has grown for the grant to further increase its scope, expanding to include more researchers, institutions and organisations. There is a great opportunity to be had in teaching more about applying synchrotron science to a wider pool of researchers who may find that using the powerful X-ray beams and laboratory equipment available through GCRF START collaborators can enhance their current work and skills set.

An important aspect of all START events is networking and knowledge sharing, and participants took full advantage of the time available between presentations at coffee breaks and mealtimes to share their experiences and cement collaborations. At the end of the event, a traditional South African ‘Braai’ (Barbeque) in the grounds of the University of Cape Town aptly rounded off a thoroughly enjoyable and fruitful workshop. Interviews, photos and videos captured the buzz of the workshop to be used to share more of START’s ongoing work, achievements and impact with our current and potential stakeholders.

Photo Credit Rebekka Stredwick, ©Diamond Light Source

Across the continent, GCRF START is working with Africa to support the Pan-African 50-year mission: AGENDA 2063 .

Click here for more information about the UN’s Sustainable Development Goal for Energy.

Investigating Solar Energy – Examining the microstructure of Organic Solar Cells

“It’s been great having Mohamed as part of our team in Oxford. Such exchanges are essential if we want to solve global challenges like climate change. Among other benefits, they foster collaboration, create lasting networks and enrich the perspectives of everyone involved.”

Prof. Dr. Moritz Riede, University of Oxford, UK 
Improving Organic Solar Cell performance for energy production 

My name is Mohamed Emad Barhouma Elsayed Abdelaal and I am an Energy Materials research scientist at the Faculty of Engineering, Ain Shams University in Cairo, Egypt.  My research involves examining the micro-structure of Organic Solar Cells (OSC’s) to monitor how the performance of the cells is affected by their micro-structure under different environmental conditions. The aim is to improve the performance of Solar Cells for energy production by controlling their micro-structure and thereby to improve their benefit for alternative energy supply and pollution reduction measures.  

As the demand on the world’s classical energy resources such as petroleum products and natural gas are increasing, we must find alternative energy resources. In Egypt, for example, the government has set renewable energy targets of 20% of the electricity mix by 2022 and 42% by 20351. Egypt is therefore investing a lot of money in massive solar farms like the Benban project in Aswan and other solar energy projects. If the efficiency of OSC’s is improved through the research being conducted, then countries like Egypt might invest in more new Solar farms. In addition, since the OSC’s can be made semi-transparent and flexible, they can be installed on the glass on buildings in crowded cities like Cairo. 

Organic Solar cells are made of organic chemical materials, while traditional solar cells are made of inorganic materials, mainly silicon. OSC’s can be made semi-transparent, flexible and potentially cheaper than Inorganic Solar Cells (ISC’s), which are opaque and generally not flexible. However, ISC’s currently have a better performance and longer lifetime compared with OSC’s. Therefore, scientists are working on improving OSC’s because of their high potential to offer cheaper and more flexible energy options2.  

Building my scientific network through GCRF START  

“North-South intercultural and interdisciplinary academic exchange between the University of Oxford and Ain Shams University is of particular benefit between these two well-established universities. Mohamed, our mutual student in the GCRF START project, co-supervised by Prof. Riede and I, has benefited from the exposure to a new academic environment and the exchange of ideas and expertise.”

Prof. Dr. Ghada Bassioni, Ain Shams University, Cairo, Egypt 

This research involves international collaboration which has been encouraged and assisted by GCRF START.  One of my research supervisors, Prof. Dr Ghada Bassioni, introduced me to the opportunities offered by START as an Energy Materials researcher. I have not only been able to attend conferences and workshops to further my knowledge and skills, providing great exposure and opportunities to build our scientific network, START has given me with access to world class facilities, equipment and devices to conduct my experiments. I collaborate with Prof. Moritz Riede’s group AFMD group in the Department of Physics at the University of Oxford and some of my experiments have been undertaken there, and at the UK’s national synchrotron – Diamond Light Source.  

Mohamed Abdelaal inside the beamline I07 experimental cabin at the UK’s national Diamond Light Source synchrotron. 
Photo credit: Mohamed Abdelaal. ©Diamond Light Source 
Shining light on OSC microstructure  

I simulate the way the molecular components of Organic Solar Cell (OSC) organise themselves (the microstructure) in devices using a molecular dynamics simulations program similar to the procedure published by T. Lee et al. ACS Applied Materials & Interfaces 10, 32413 (2018). The simulations can be likened to real OSC materials ‘in situ’ and ‘ex situ’ to compare and validate the results achieved in simulation. We use a technique called X-ray diffraction which enables us to study surfaces and interfaces on an atomic scale and the micro-structure and interface evolution in real-time under vacuum conditions. 

To examine the microstructure of the OSC during evaporation, different tests are done including X-ray diffraction in the MINERVA chamber on the high resolution Beamline I07 at Diamond (Fig. 1&2) This involves evaporating the materials which make up the OSC onto a device surface (substrate) under X-ray illumination, allowing X-ray diffraction images to be collected ‘in situ’ as the materials are deposited. In this way, we can observe how the molecules change in their molecular packing (microstructure) over time as they land on the substrate microstructure. The MINERVA chamber also enables us to study how the microstructure changes in response to different environmental factors, such as temperature, humidity, and various gases. Sometimes, however, we evaporate the OSC’s at the University of Oxford using the Vacuum Evaporator (ECHO1) facility with the AFMD group, after which we examine the samples at Diamond using the X-ray diffraction process. In this case we don’t use MINERVA and the process of examination is called ‘ex situ’.  

FIG. 1. Overview of the design of the MINERVA chamber. It consists of four modules: the deposition chamber houses the low temperature evaporation (LTE) sources and quartz crystal microbalances (QCMs); the scattering chamber with beryllium windows and slits; the sample manipulator using an external hexapod to allow accurate positioning of the sample; the vacuum component chamber with all pumps, gauges, and valves. Review of Scientific Instruments88, 103901 (2017) 
DOI: 10.1063/1.4989761, Copyright © 2017 Author(s) 
FIG. 2. Cut-through of the MINERVA chamber looking from the front (access ports), showing key internal components and the path of the X-ray beam. 
Review of Scientific Instruments88, 103901 (2017) DOI: 10.1063/1.4989761, Copyright © 2017 Author(s) 
Building OSC’s and molecular dynamics simulation of OSC microstructure 

Building the OSC’s themselves is done using ‘ECHO1’, a vacuum deposition chamber at the University of Oxford. The needed materials are supplied in solid state commercially or from collaborators. The organic materials are evaporated onto a glass substrate and the layer thickness of the Solar Cell is subsequently monitored through the evaporation rate and the length of time of evaporation. Co-evaporation is also possible, which allows the evaporation of more than one organic material at the same. After achieving the required thickness, the Solar Cell is cooled down and then encapsulated inside a nitrogen filled box under inert conditions, the solar cell is ready for further examination.   

Mohamed Abdelaal using the glove box in the Vacuum Evaporator (ECHO1) at the University of Oxford  in the UK for sample handling. 
Photo credit: Mohamed Abdelaal. ©Diamond Light Source 

I started conducting my research in September 2018 and before the end of my second year, I hope to publish my first paper. During the course of my research, I personally believe that every step forward is a huge achievement, without which we would never be able to proceed further. One achievement worth mentioning is that, with Prof. Dr. Moritz Riede support, I have learned molecular dynamics simulation of the micro-structure of OSC’s. I also learned how to write scripts and although they are basic and simple, they automate the simulation which reduces the time loss between simulation steps.  Every time the simulation is completed successfully, I feel so happy and proud that I have learned something new. 

GCRF START fostering global partnerships and internationalisation  

Commenting on the importance of international partnerships such as GCRF START for students like Mohamed, Prof. Dr. Ghada Bassioni, Professor of Chemistry and Head of the Chemistry Division at the Faculty of Engineering at Ain Shams University, said, 

“Overall, the openness for African, and especially Egyptian universities to internationalisation is growing rapidly, with unhindered communication channels and inexpensive travel. Global partnerships and fostering relationships with other institutions whether on an individual or institutional basis are the main source for international students and academic exchange. International students increase social and cultural diversity, enrich the research and learning environment and help local students to develop internationally relevant skills. There are a lot of benefits for seeking an international academic environment, whether it is to develop new ideas or tap into new sources of funding or to gain access to specialised equipment. As a result of the expansion of communication methods and the ease of international travel, one in five of the world’s scientific papers are co-authored internationally.” 

Read more here about the openness for African universities to internationalisation 

Learn more about Solar energy here and the differences between Organic and Inorganic Solar Cells here  

Read more here about the UN Sustainable Development Goal 7 for Energy 

Mohamed Abdelaal profile page here

Footnotes:

1 IRENA (2018), Renewable Energy Outlook: Egypt, International Renewable Energy Agency, Abu Dhabi 

2 Organic Solar Cell Materials toward CommercializationRongming Xue, Jingwen Zhang, Yaowen Li,* and Yongfang Li  DOI: 10.1002/smll.201801793 

Investigating energy materials for efficient and cost effective conversion of sunlight into electricity

“Focusing on universal access to energy, increased energy efficiency and the increased use of renewable energy through new economic and job opportunities is crucial to creating more sustainable and inclusive communities and resilience to environmental issues like climate change”

UN Sustainable Development Goal 7: Energy

The case for localised energy generation

The rising global demand for energy and the depletion of fossil-based fuels has increased the research focus on new materials which could contribute to efficient localised energy generation, particularly in remote areas with a scarcity of electricity.

Of the nearly 1 billion people globally functioning without electricity, 50% are found in Sub-Saharan Africa alone (UN, 2019), where the focus on finding localised energy generation solutions is a welcome and timely opportunity, especially in schools and clinics located in rural areas far from the existing electricity supply or grid.

Investigating energy materials for efficient conversion of sunlight into electricity

Dr Daniel Wamwangi is a Co-Investigator within the GCRF START programme conducting fundamental research into energy materials for solutions which could one day revolutionise the energy landscape across Africa and beyond. Originally from Kenya and based as Associate Professor in the School of Physics at the University of the Witwatersrand in South Africa, Professor Wamwangi’s research on energy materials focuses on energy conversion with the aim of converting sunlight into electricity in the most efficient and cost effective way.

“The availability of alternative energy at increased efficiencies with lower costs and improved environmental footprints has domino effects on the social economic landscape,” explains Dr Wamwangi. “Benefits such as pumped water supply and purification through local solar power generators, solar based lamps and solar powered electronic devices such as cell phones could radically improve the living standards of populations in these areas.”

Dr Daniel Wamwangi performing the electronic characterisation of energy conversion materials at the University of the Witwatersrand, South Africa, using the physical property measurement system. Photo credit: Daniel Wamwangi

Finding the right energy conversion parameters

First the right parameters must be established and tested; only then can prototyping begin. There are two prongs of energy conversion that are of prime interest and focus, namely photovoltaic and thermoelectric conversion. The former involves harnessing sunlight to produce electricity, while the latter entails the conversion of heat into electricity.

The conversion of sunlight into electricity is popularly known as photovoltaics and the devices that enable the conversion are known as solar cells.

“The performance parameters that determine the commercial viability for sustainable renewable energy especially in photovoltaics include efficiency of conversion, lifetime and costs,” explains Dr Wamwangi. “In the current materials-science landscape, Silicon (Si), an element in the periodic table, has exhibited the highest efficiency of light to electricity conversion at 28%. However, the costs of processing are prohibitive and thus alternative materials and technologies are crucial to replace Si.”

This is the crux of Professor Wamwangi’s research in which cost-effective materials such as Organic materials (organic polymer based solar cell) and Inorganic materials (halide perovskites – a hybrid between inorganic and organic materials, which can be solution-based), and control of solar energy in materials (supplementary light management schemes) are investigated and developed. 1

“Hybrids are found in most cases in powder form and retain their properties even when in solution,” Professor Wamwangi explains. “They can be combined from a composite solution that is photo-responsive, which means they can take light and produce electrons and positive charges (holes) leading to voltage and electrical current.”

Supplementary light management schemes

“Supplementary light management schemes are one way to improve efficiency and this is where a lot of solar research these days is focusing. If we look at the energy budget not all the light from the sun is useful to solar devices because every material has a unique energy value,” says Dr Wamwangi. “This means that some of the light that is not used would be wasted. Therefore, we combine the energy of the light particles from the wasted light in order to increase the energy of the wasted light so it can be used by the solar cell. This increases the useful light that can be absorbed by the materials in the device.”

Light management uses nanostructures to modify the emission of light within the visible spectrum with a select number of atoms in a patterned manner to capture light (plasmonics), increasing (up conversion) and decreasing (down conversion) the energy from the sun, as Professor Wamwangi explains,

“When the energy from the sun is very large it produces hot electrons and energy is lost in the form of heat; when the temperature increases, the efficiency of the solar cell decreases, so this energy has to be decreased through the down conversion as part of a light management process.”

Organic-based solar cell devices operate on an entirely different conversion mechanism involving a combination of two interconnected materials (donor and acceptor of electrons) with entirely different electrical properties2. More recently, a hybrid of organic and inorganic materials also popularly known as Halide perovskites is intensively studied due to its associated high photo conversion efficiency.

These low-cost energy materials are predicted to replace Si-based photovoltaics through the addition of a third component to form a ternary system (three interconnected networks of materials) in consumer electronics. However, the production of current in these materials is dependent on the structure at the micro level (as previously investigated by Professor Wamwangi’s PhD student Dr. F. Otieno et al 3).

Access to state-of-the-art synchrotron techniques, collaboration and upskilling

This is where GCRF START makes a significant difference, providing researchers like Professor Wamwangi and his colleagues with access to the UK’s Diamond Light Source synchrotron and sophisticated techniques known as GIWAXS and GISAXS (Glancing incidence Wide/Small Angle X-ray Scattering). These techniques are used to study the arrangement of molecules or atoms in a solid to nanometer length scales in order to probe the type of microstructure of these materials to elucidate the electron (negative charge) and hole transport (positive) charge within the network.

© Diamond Light Source

“The factors that determine the microstructure of interconnected networks include temperature and time during processing,” says Professor Wamwangi, “Using the facilities available at Diamond through START, as well as expertise within the START family, we can correlate the microstructure with the production of current (photocurrent) and with the absorption of light on a dynamic basis.”

Besides the research fundamentals, Dr Wamwangi speaks highly of the fact that START provides a collaborative forum for scientists in Africa working in this field of Energy Materials,

“As seen in the recent publication on perovskite solar cells with START collaborators from both Africa and the UK, START increases the impact, quality and sustainability of our research publications and outputs, as well as the overall visibility and influence of African scientists and innovators globally.”

Footnote:

1) F.Otieno, B. Mutuma, M. Airo, K. Ranganathan, R. Erasmus, N. Coville D. Wamwangi 2018, https://www.sciencedirect.com/science/article/pii/S0040609017300573

2) F.Otieno, B. Mutuma, M. Airo, K. Ranganathan, R. Erasmus, N. Coville D. Wamwangi 2018

3) F.Otieno, B. Mutuma, M. Airo, K. Ranganathan, R. Erasmus, N. Coville D. Wamwangi 2018

4) Collaborators in the microstructure project of organic photovoltaics: Prof. D. Billing the principal Investigator in the START project, Wits University; Dr. Moritz Riede, Department of Physics, Oxford University, Dr. Thomas Derrien, Dr. Francis Otieno, School of Physics/Chemistry, Wits University (Professor Wamwangi’s former PhD student).

Sustainable solutions to the energy challenge – Fast oxide ion conductors for solid oxide fuel cells

“Our vision one day is to see such fuel cells commercialised and distributed around Africa and the rest of the world, and we are excited about playing our part in developing these solutions.” Sikhumbuzo Masina, University of the Witwatersrand, South Africa.

Sustainable solutions to the energy challenge

Globally and locally in Africa, we need sustainable and cost effective solutions to the energy crisis, particularly in the light of climate change, pressures on energy resources and rising energy costs (UN Sustainable Development Goal 7). According to the UN, slightly less than 1 billion people (13% of the global population) are functioning without electricity and 50% of them are found in Sub-Saharan Africa alone.

Our research group in the Molecular Science Institute at the University of the Witwatersrand, South Africa, largely looks at energy materials for alternative energy solutions – from hybrid perovskites (materials that have a potential use in making photovoltaic cells for solar panels which comprise both organic and inorganic constituents) to electroceramics such as fluorite structured material (materials where the metal atoms form a face centred cubic packing, and the non-metals fill in the tetrahedral holes in between the metal ions), to Solid Oxide Fuel Cells, and even some battery anode materials.

This research is supported, in part, by GCRF START through UK-Africa collaborations to find solutions to these global challenges. START helps our group develop expertise in the use of cutting edge synchrotron techniques (through the UK’s synchrotron light source, Diamond) and neutron techniques, in order to characterise energy materials adapted to the needs of the African continent.

Sikhumbuzo Masina with the START banner
Credit Sikhumbuzo Masina

Alternative power generation – the case for Solid Oxide Fuel Cells (SOFCs)

“Energy is central to nearly every major challenge and opportunity the world faces today. Be it for jobs, security, climate change, food production or increasing incomes, access to energy for all is essential,” UN Sustainable Development Goal 7.

SOFCs are electrochemical devices that convert chemical energy directly to electricity without a combustion step. They are highly efficient energy conversion devices, possess fuel flexibility, and demonstrate zero or reduced Carbon dioxide (CO2) emissions when Hydrogen gas (H2) or natural gas are used as fuel respectively.

Achieving efficiencies of close to 80% depending on the power generation mode, SOFCs can be used off-grid which is vital in countries that experience daily power cuts (rolling blackouts or ‘load shedding’), especially in rural areas where access to electricity can be scarce, or even non-existent.SOFCs are versatile – they can be used as an auxiliary, stationary or distributed power sources, which eliminates the need for expensive transmission cables.

In our research, we examine the effect of temperature on the stability, conductivity, thermal expansion and related properties of the materials used in SOFCs. The aim, in the near term, is to design and study the behaviour of materials used in the fuel cells ‘in-situ’, as they operate at various temperatures, in a quest to identify sufficiently stable combinations to allow for further development and ultimately commercialisation (these materials include solid solutions of bismuth oxide, cerium oxide and yttrium oxide).

One such research project is that of Sikhumbuzo Masina, Caren Billing, and Professor David Billing from the Molecular Science Institute at the School of Chemistry, University of the Witwatersrand, South Africa looking at Bi2O3, a potential SOFC electrolyte. Sikhumbuzo describes this research which is the focus of his PhD.

The effects of impurity cations on the average and local structure of Bi2O3, a potential SOFCs electrolyte [1]

My PhD research focuses on studying the effects of impurity cations on the average and local structure of Bi2O3, a potential SOFC electrolyte .This involves adding foreign (impurity) atoms into a material and observing the effect of these atoms on the arrangement of the host atoms and correlating this with the change in physical properties like electric conductivity, as well as thermal expansion and stability.

Bi2O3 in its defect fluorite δ-phase – a certain arrangement of atoms in the fluorite structure where some of the tetrahedral sites are empty (defective) or vacant – is reported to have the highest oxide ion conductivity at 730 °C. However, its local structure has proven inscrutable; it cannot be probed using conventional X-ray diffraction techniques and the four published models have proved inadequate in explaining all our observations and measurements, leaving the fundamental understanding of the real structure property relations of this family of materials as an unresolved enigmatic scientific challenge.

This seemingly insurmountable local structure problem is compounded by the fact that the δ-phase is only stable within a narrow range of 730-824 °C. Substitution of the host atoms by other foreign atoms (Doping) stabilises the δ-phase to room temperature but the oxygen sublattice arrangement undergoes some ordering and degradation of conductivity is observed with long term annealing (Where we heat powder in a furnace at constant temperature for a certain period of time)at temperatures less than 600 °C.

To conjure up solutions to these problems, complimentary local probes such as pair distribution functions (PDFs) and extended X-ray absorption fine structure (EXAFS) techniques are needed to study the local structure in greater detail. These techniques are sensitive to the local environment around a particular atom revealing, for example, the distances and angles between groups of atoms and how they are arranged and vibrate in relation to each other (correlations), hence providing the structure of a material at a more local level.

In our project, we study both the average and local structure (repeat pattern over long distances and local atomic arrangements respectively) of the solid solutions of Bi2O3 which will help elucidate what entails a best fast oxide ion conductor. This will, in turn, help us design solid electrolytes that will enable solid oxide fuel cells to operate at intermediate temperatures (500-800°C) and reduce their capital cost – a current stumbling block to their commercialisation.

Knowledge exchange and collaboration through START Energy Materials Workshops

“My hope is to apply for access through START to use the state-of-the-art Diamond Light Source Synchrotron facilities for my research. It is this collaboration, knowledge exchange and the potential for access to cutting edge facilities to make a meaningful impact in the world that makes interacting with the START community so beneficial.”

I attended a very informative START workshop at the University of Cape Town (16-17 Dec 2019) where we heard talks from scientists across the UK and South African Energy Materials community. The workshop was a great platform to build connections with START for future collaborations.

I spoke to Dr Sofia Diaz-Moreno, a Principal Beamline Scientist at Diamond about the options to use the synchrotron to look at the local environment and oxidation states of the metals we are using in our SOFC research at the University of the Witwatersrand.

Dr Sofia Diaz-Moreno, Diamond Light Source Principal Beamline Scientist,
speaking at the START Energy Materials Workshop.
Credit Rebekka Stredwick. © Diamond Light Source

The workshop also heard from Dr Daniel Bowron, who is the leader of the ISIS Disordered Materials Group. He described the possibility of also applying to ISIS to do neutron-studies on our materials to probe the oxygen environment so that we can understand how the oxygen sublattice would impact these kinds of solid oxide fuel cell devices when used under intermediate temperatures for a very long time.

Participants at the START Energy Materials Workshop which took place in Cape Town from 15-17 Dec 2019. Sikhumbuzo Masina is in the front row (second from the left).
Credit Rebekka Stredwick. © Diamond Light Source

Footnote:

[1]Sikhumbuzo M. Masina (a), Caren Billing(a), David G. Billing(a,b), (a)Molecular Science Institute, School of Chemistry, University of the Witwatersrand, South Africa; (b) DST-NRF Centre of Excellence in Strong Materials, University of the Witwatersrand, South Africa

Computational modelling of catalysts for CO2 recycling and renewable fuel synthesis

“Efficient conversion of CO2 to methanol is one of the grand challenges of contemporary catalytic sciences to which Michael Higham’s work through START is making a key contribution,”

Professor Richard Catlow FRS

Addressing the global CO2 emissions and energy challenges 

Rising atmospheric carbon dioxide (CO2) levels attributed to burning fossil fuels is a major economic and environmental issue for Africa and globally, in particular the association with increasing global temperatures, which pose a significant risk for current and future generations.  

Although global emissions of carbon dioxide COhave increased by almost 50 per cent since 1990, experts like the UN’s Intergovernmental Panel on Climate Change (IPCC) agree it is still possible to limit the increase in global mean temperatures using a wide array of technological measures and changes in behaviour. Such measures are set out in the UN’s Sustainable Development Goal 7 Energy.  

One such approach involves Catalysis and renewable combustible liquid fuels to enable new technologies to remove CO2 from the atmosphere, converting it into valuable and versatile synthetic fuels. This would allow for an entirely closed carbon cycle, reflecting nature’s own carbon cycle1. The COwould be captured and converted into a liquid fuel; this fuel would then be burnt and the COre-captured, closing the gap. 

Shipping and aviation are amongst the largest consumers of fossil fuels and greatest contributors to CO2 atmospheric pollution yet cannot be easily converted to utilise electricity from renewable and non-polluting sources. For these applications, catalytic technology could be vital for providing alternative fuel sources. 

Computational techniques to investigate both new and existing catalytic materials 

Dr Michael Higham is a START-funded expert providing computational insights to support experimental work utilising capabilities at the UK’s national synchrotron – Diamond Light Source.  His research entails applying computational techniques to investigate both new and existing catalytic materials to utilise CO2, in particular for methanol synthesis. 

Methanol is an important industrial feedstock material and can be used as a renewable fuel when generated from atmospheric CO2; hydrogen obtained sustainably from efficient water splitting processes is another key area of catalytic research for energy applications.  

Methanol can be used as both a conventional combustible fuel, as well as in Direct Methanol Fuel Cells (DMFC)2 , which offer an alternative to hydrogen fuel cells with fewer safety and engineering issues to be addressed. Furthermore, methanol can also be used as a starting material for subsequent catalytic processes to produce hydrocarbons, which are chemically equivalent to existing liquid fuels and allow for maximal utilisation of existing technologies.  

Efficient conversion of CO2 to methanol and ZnO-supported catalysts 

Dr Higham’s research has mostly focused on copper (Cu) based catalysts for methanol synthesis, which have been used extensively for the conversion of synthesis gas (a mixture of CO2, CO, H2O and H2 originating from coal gasification processes). In particular, the Cu/ZnO/Al2O3 catalyst has been used successfully for decades. However, much remains to be understood regarding how precisely these catalysts enhance methanol production.  

Fig 1. A CO2 molecule interacting with the surface of a copper / zinc oxide catalyst. Note the bent shape of the CO2 molecule, which is a result of its interaction with the catalyst surface, in contrast to the usual linear geometry observed. Blue spheres represent Cu atoms, dark and light grey spheres represent surface and subsurface Zn, respectively, whilst black and red spheres represent C and O, respectively. 
Copyright: Dr Michael Higham & David Jurado 

 “As part of my research, I have conducted extensive computational investigations into the mechanism of CO2 and CO hydrogenation to methanol over unsupported Cu catalysts, providing detailed insights into key intermediates and limiting elementary processes in the overall reaction” says Dr. Higham.

This work will provide a benchmark for future computational studies examining ZnO-supported catalysts, which in turn will provide atomic-scale insights into the origin of catalytic activity that will directly complement experimental synchrotron studies. 

To this end, my project has also investigated the structure and morphology of Cu clusters supported on ZnO, in order to derive suitable models for the aforementioned computational investigations of supported Cu/ZnO catalysts3.” 

It is expected that the work investigating unsupported Cu catalysts will be published imminently in a leading peer-review journal; meanwhile, a second manuscript concerning the growth of Cu clusters over ZnO supports is in preparation, and further calculations are underway to explore the methanol synthesis reaction over model Cu/ZnO catalysts, in collaboration with visiting Masters students from the University of Freiburg, Germany, and the National University of Singapore. 

Fig 2. Some important reactants, intermediates and products associated with CO2 conversion to methanol over a copper catalyst surface. Blue spheres represent Cu, grey spheres represent C, red spheres represent O, and white spheres represent H. 
Copyright: Dr Michael Higham & David Jurado 

The importance of computational investigations in catalytic research 

Dr Higham explains that computer simulations and modelling are vital components in catalytic research, supporting and corroborating by providing an atomic-scale insight into the phenomena that are responsible for macro-scale observations in actual experiments.  

“We can test hypotheses for explanations of observed real-world behaviour, and on the flipside, we can use what we already know about well-studied systems to examine new, novel materials, and therefore help to direct future experimental studies.” 

Dr Michael Higham working on computational insights into experimental data with Dr Mohamed Fadlalla from the University of Cape Town  

Addressing fossil fuel dependence in Africa 

These approaches could offer hope to countries across Africa and also address key polluting industries such as aviation and shipping.  

 “Whilst there is a great deal of focus on renewable electricity sources such as wind and solar, sustainable and renewable combustible liquid fuels will make an important contribution to reducing humanity’s dependence on unsustainable and polluting fuel sources.

This is especially true for Africa and the rest of the developing world, where existing infrastructure could be readily and inexpensively adapted to accommodate such synthetic fuels, whereas infrastructure to enable widespread use of renewably generated electricity such as for transportation purposes would require substantial new investment.” explains Dr Michael Higham.

About the contributors: 

Michael Higham completed a PhD in Chemical Science and Technology at the Institut Català d’Investigació Química (ICIQ, Catalan Institute of Chemical Research) in November 2017. Michael joined Professor Richard Catlow’s group at Cardiff University in August 2018, supported by the GCRF (Global Challenges Research Fund). Michael’s work forms part of the START (Synchrotron Techniques for African Research and Technology) project, providing computational insights to support experimental work utilising the synchrotron facilities at Diamond Light Source Ltd. Michael’s current research project concerns Cu-based catalysts for methanol synthesis from CO2

Professor Richard Catlow is Foreign Secretary and Vice President of The Royal Society, 

Professor of Catalytic and Computational Chemistry at Cardiff Catalysis Institute and Professor of Chemistry at UCL, and is a founder of the UK Catalysis Hub: https://ukcatalysishub.co.uk/  

Footnotes:

1 Olah, G. A.; Goeppert, A.; Prakash, G. K. S. Chemical Recycling of Carbon Dioxide to Methanol and Dimethyl Ether : From Greenhouse Gas to Renewable, Environmentally. J. Org. Chem. 2009, 74 (2), 487–498.

2 Hogarth, M. P.; Hards, G. A. Direct Methanol Fuel Cells: Technological Advances and Further Requirements. Platin. Met. Rev. 1996, 40 (4), 150–15

3 Collaboration with Alexey A. Sokol and David Mora-Fonz, both of University College London.

Catalysis for the Climate Change Challenge: Iron-based alloys as catalysts for CO2 Hydrogenation

“Climate change is a global challenge that does not respect national borders. It is an issue that requires solutions that need to be coordinated at the international level to help developing countries move toward a low-carbon economy.” UN Sustainable Development Goal 13 

The UN Climate Panel (IPCC) calls for the elimination and reversal of COemissions to the atmosphere as a matter of urgency to avoid potentially “catastrophic climate change”. One of the main barriers to this, however, is the large amount of readily available energy in the form of fossil fuels, which is currently hard to compete with using alternative or renewable sources, particularly on the African continent.  

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Developing sustainable energy in Africa

There are unique challenges to developing sustainable energy in Africa. Large swathes of the population live off-grid with little access to conventional energy sources. The degradation of energy devices in an environment of heat and dust, and the high initial capital costs of traditional energy production installations or storage systems causes problems for the wider dissemination of conventional energy services. Prof. Dave Billing from the University of Witwatersrand looks forward to developing their use of synchrotron techniques:

“Being able to access the unique techniques offered by a synchrotron like Diamond is a step change for us in skills development as well as an opportunity to compete with our science on a world stage.”

PROF. DAVE BILLING, UNIVERSITY OF WITWATERSRAND

Research into new materials to aid the capture of energy through sunlight such as using photovoltaic materials and catalytic processes will potentially aid the promotion of innovative sources of energy that draw on readily accessible energy sources abundantly available in the local environment.

For information on other Energy Materials research please click on the name below:

University of the Witswatersrand, Co-Investigator: David Billing

Photovoltaics at the University of Sheffield

The Electronic and Photonic Molecular Materials group at the University of Sheffield develops novel photovoltaic materials and processes to enable a new era of low-cost solar energy. Our work centres around the development of organic-inorganic metal-halide perovskites and related materials. These perovskites have shown the potential for low-temperature processed, high efficiency, printable and spray-coatable layers which could be the future for incredibly low-cost energy. Perovskites could also have applications for off-grid generation, connecting communities that currently don’t have access to consistent electricity.

As part of the START project, EPMM use our experience of synchrotron techniques (such as Grazing Incidence Wide-angle X-ray Scattering, GIWAXS) to collaborate on the analysis of structural formation and degradation of perovskite materials. High efficiency solar cells are possible at lab scale, but without careful design perovskites can degrade rapidly from a combination of common environmental factors like moisture and oxygen. By investigating the effect of these various factors we can understand degradation processes and design new material formulations and layers that are resistant to these impacts. Our work also looks at scalability of the layer formation processes and understanding how they form during spray-coating or evaporating. Together with expertise drawn from other Universities in the project, we can develop fundamental insights into the mechanisms at work when making or breaking perovskites, paving the way for commercialisation of these innovative materials.

A large batch of tiny perovskite solar cells being ‘spin-coated’ and heated on a hotplate inside a glove box ready for testing in Sheffield

New collaboration opportunities for computational insights into catalysis

A successful secondment by GCRF START computational scientist, Dr Michael Higham, has led to exciting new computational modelling collaborations involving leading catalysis institutes in South Africa and the UK.

These opportunities range from investigating adsorption induced magnetisation changes in nickel catalysts, to research into bimetallic catalysts for CO2 hydrogenation of environmental and industrial importance in the search for sustainable, clean energy sources to tackle climate change.

Dr Higham, who is a START-funded Postdoctorate Research Associate at Cardiff Catalysis Institute working with the UK’s national synchrotron light source, Diamond Light Source and the UK Catalysis Hub, spent two months from December 2019 to January 2020 at the University of Cape Town meeting researchers, undertaking initial computational work, and getting to know the projects.

Now back in the UK, Dr Higham’s aim is to provide theoretical inputs through computational modelling in order to support findings from experimental results.

One of these projects focusses on bimetallic alloy catalysts for methanol synthesis and conversion involving Dr Mohamed Fadlalla and Christopher Mullins from the University of Cape Town’s Centre of Catalysis and c*Change, South Africa’s DST-NRF Centre of Excellence in Catalysis Research.

“In early December 2019, our team from the University of Cape Town and Southampton University (UK) visited the Diamond Light Source synchrotron and used the B18 beamline to study the influence of substituents in the ferrite structure on the reduction behaviour and carbon dioxide hydrogenation reaction to valuable products (e.g. fuels),” Dr Fadlalla explains. “The next step is Michael’s computational work to help us to calculate certain insights from the results such as how the catalyst looks and how the reactant is interacting with the catalyst.”

The computational calculations will examine the catalytic product distributions which provide detailed insights into possible explanations for observed catalyst selectivity, as Dr Higham explains,

“Through modelling adsorption energies, activation energies and reaction energies we hope to shed light on what happens on the catalyst’s surface. We want to compare the observed, experimental data with the computational calculations.”

Michael Higham (L) & Mohamed (R) Fadlalla working on bimetallic alloy catalysts for methanol synthesis and conversion using computational studies.
Photo credit: Rebekka Stredwick; ©Diamond Light Source Ltd.

Another project focuses on the rationalisation of experimentally observed adsorption-induced changes in magnetisation of Ni particles. Working together with Dominic de Oliveira from UCT, Dr Higham’s intention is that the computational results, in conjunction with the experimental work, will pave the way for possible new techniques to employ magnetism to probe surface area and composition.

“The secondment was a great opportunity to meet some really enthusiastic scientists doing some excellent work on catalysis,” Dr Higham reports. “The collaborations represent not only a trajectory for progress in solving real-world energy problems but also a fundamental knowledge foundation that can inform future studies”.

“Computational experts like Michael can predict how certain catalysts perform and we can try to confirm that with our techniques which is a reciprocal learning process,” says Professor Michael Claeys, Director of c*Change. “This expertise informs us and we inform them through the results which is something a single group can’t do because very specific expertise is needed. Collaborating provides some of the most powerful learning opportunities which really shape your people.”

Such collaborations through START not only enable shared learning, they increase opportunities for publications and – in Dr Fadlalla’s words – “give Africa a bigger footprint in the wider catalyst society”, as Co-I on the START grant, Dr Peter Wells, explains,

“START is a fantastic opportunity for the UK to work in concert with our African partners to tackle shared challenges. It is clear that the excitement generated can be inspirational and helps to further integrate research partnerships.”

More about the contributors

Dr Michael Higham works with Professor Richard Catlow’s group at Cardiff University and is supported by GCRF START to provide computational insights for experimental work utilising the synchrotron facilities at Diamond Light Source Ltd. Michael’s current research project concerns Cu-based catalysts for methanol synthesis from CO2.

Dr Mohamed Fadllala is a Post Doctorate Fellow at the University of Cape Town’s Catalysis Institute in the Department of Chemical Engineering.

Dr Peter Wells is an Associate Professor and a Co-I on the START grant. He currently has a joint appointment between Diamond Light Source Ltd and the University of Southampton.

Professor Michael Claeys is the Director of DST-NRF Centre of Excellence in Catalysis, c*change, hosted by the Catalysis Institute in the Department of Chemical Engineering at the University of Cape Town, South Africa

Cardiff University: Computational studies of Cu-based Catalysts for CO2 Conversion to Methanol

Image: Bent activated CO2 molecule adsorbed on two different Cu facets

Methanol (CH3OH) is an attractive target molecule for carbon dioxide (CO2) conversion. Carbon dioxide is a greenhouse gas pollutant and contributes to global warming. With these pressures putting strain on the earth’s resources, research is needed to understand how CO2 can be removed from the atmosphere.

Additionally, carbon dioxide is an abundant source of carbon. If CO2 can be converted into feedstock materials such as methanol, it represents a clean and essentially renewable source of methanol to produce a wide range of economically valuable products. As well as being a major industrial chemical product itself, methanol is used in the production of synthetic hydrocarbons, and could also be used as a stable hydrogen source for hydrogen fuel cells.

Researchers at Cardiff University’s Catalysis Institute are undertaking investigations into catalysts for methanol synthesis. Catalysts are substances or materials that alter the rate of a chemical reaction without it being consumed as part of the catalytic cycle. The investigators will use computational studies to better understand the role of the zinc oxide (ZnO) support material in commercial Cu/ZnO/Al2O3 catalysts by comparison with unsupported copper (Cu) catalysts.

The team’s work will ultimately support the design of novel catalysts to produce methanol that could become a key substance in creating renewable energy sources.