Double first! First synchrotron user from the University of Zululand solves partial structure of the Schistosomiasis (Bilharzia) G4LZI3 universal stress protein

In a ‘double first’, Dr Priscilla Masamba, has become the first University of Zululand student to use the UK’s National Synchrotron Light Source, Diamond, and solve the partial structure of a protein from Schistosoma mansoni. With access to the synchrotron made possible by GCRF_START, Priscilla employed sophisticated robotic instruments and macromolecular X-ray crystallography techniques remotely from South Africa to solve the partial structure of the G4LZI3 universal stress protein – a protein regarded as a target for novel medicines for treating the disease Schistosomiasis. The experiments took place in February 2020, using the Diamond’s I04-1 beamline.

Dr Priscilla Masamba in the laboratory at the University of Cape Town.
Photo credit Rebekka Stredwick. ©Diamond Light Source

Schistosomiasis is an acute and chronic disease caused by parasitic worms (schistosomes) endemic in more than 78 countries with an estimated 4 million people infected in South Africa alone. The disease requires an intermediate host, the freshwater snail Bulinus africanus, and occurs most often in rural areas where people become infected during routine agricultural, domestic, occupational, and recreational activities which expose them to infested water.

Only one drug, Praziquantel, is available to treat Schistosomiasis leaving people vulnerable to schistosome resistance and this treatment is only partially effective in treating adults.  The aim of Priscilla ’s research is therefore to generate insights for the design of alternative treatment regimen targeting specific stages during the developmental cycle of the schistosome.

Describing the experiments at Diamond as “close to a cool sci-fi movie,” Dr Masamba was able to control the sophisticated instruments on I04-1 beamline and collect data in real time from the University of Cape Town’s (UCT’s) Aaron Klug Centre for Imaging and Analysis – established as a GCRF_START Centre of Excellence for structural biology research.

“Remote data collection at Diamond was so exciting!” Dr Masamba explains, “I could literally control and see a robot that was thousands of miles away on the other side of the world, mount a microscopic crystal (sample) within the firing line of a powerful X-ray beam, and determine the amount of energies released by light emitted from the sample caused by incident X-ray beams, and all of this while working from the laboratory in Cape Town. I didn’t need to get in a plane to achieve the one of the most imperative steps in the crystallography process! The whole experience provided me with rare exposure to the world of X-ray crystallography, impacting my view of science in a spectacular way.”

Proteins are thermodynamically and kinetically responsible for all biochemical processes that occur, and are therefore responsible for coordinating, regulating and dictating numerous metabolic functions. Exposure of the Schistosome parasite to extreme conditions during its developmental stage triggers the expression of heat shock proteins and universal stress proteins, of which the G4LZI3 USP has been identified as a potential druggable target for the development of alternative treatments (schistosomicides). Techniques like X-ray crystallography can provide insight, not only into the composition of these biomolecules, but also into their various interactions with other compounds and their roles in biological mechanisms, an imperative foundation for rational drug design and development.

Before the experiments took place, diffraction of the crystals was first checked at UCT using a diffractometer. Crystals from these conditions were then flash-frozen in liquid nitrogen and shipped to the Diamond synchrotron to be used as samples.

The BART robot and sample holder on beamline I04-1. The drum (Dewar) contains liquid nitrogen, and space for 37 pucks, each containing 16 pins, so 592 samples. These pins and pucks are shipped in a Dewar from South Africa. The robotic arm is grey and is shown ready to pick up the next sample. When it selects the next sample, this is placed onto the goniometer, which holds the sample and rotates it for data collection.
©Diamond Light Source.
The goniometer on beamline I04-1 holds the microscopic crystal on a pin with the sample on the end of it which rotates in the firing line of the powerful X-ray beam.
©Diamond Light Source.

The solved structure of the S. mansoni G4LZI3 is a success story for the University of Zululand, a small resource-constrained university in the rural part of KwaZulu-Natal Province of South Africa. The University of Zululand lacked the resources required for Dr Masamba to achieve all her objectives for her PhD, which meant the collaboration through START in order to carry out the experiments needed was imperative both professionally and personally.

Priscilla is thankful for the guidance and mentoring from her PhD supervisor, Professor Abidemi Paul Kappo, who heads up the Biotechnology and Structural Biology (BSB) Research Group in the Department of Biochemistry and Microbiology at the University of Zululand, and from START Principal Investigator, Professor Trevor Sewell, of UCT’s Aaron Klug Centre for Imaging and Analysis, both of whom helped Priscilla overcome various challenges.

“I have been able to learn and cultivate scarce, critical and sought-after skills here in Africa in the fields of bioinformatics and drug discovery, molecular biology and especially, structural biology,” says Dr Masamba. “These include gene cloning, recombinant protein expression and purification, as well as characterisation of proteins. This has not been an easy task because I am from an underrepresented group in science as a black female and study at a historically-disadvantaged and resource-constrained institution.”

Professor Abidemi Paul Kappo, (left) head of the Biotechnology and Structural Biology (BSB) Research Group in the Department of Biochemistry and Microbiology at the University of Zululand, and START Principal Investigator, Professor Trevor Sewell (right), from the University of Cape Town’s Aaron Klug Centre for Imaging and Analysis.
©Diamond Light Source.

An important objective of the START programme is to increase the number of structural biologists in similar less developed universities in South Africa and across the continent. This can present complex challenges, not least because many students are ill-equipped for work in the field of structural biology.

“A key concept behind the creation of the START Centre of Excellence at UCT’s Aaron Klug Centre for Imaging and Analysis, for example, is to provide the necessary infrastructure to enable senior students and staff at South Africa’s historically disadvantaged universities to access both the human and material resources necessary to overcome the difficulties and determine protein structures,” Professor Sewell says. “We count the collaboration with Professor Paul Abidemi Kappo and Dr Masamba as a major success in this respect.”

This collaboration between Prof. Kappo and Prof. Sewell was enabled by GCRF_START with Prof. Sewell providing the technological resource for the G4LZI3 structural biology project, as well as the linkage to Diamond.

“Above all, Professor Sewell’s enthusiasm to train and develop a “critical mass” of students in Structural Biology is second to none,” Prof. Kappo says. “This has been a joint effort and a model of national and international collaboration. In addition to the technological resources through UCT and linkage with Diamond in the UK, funding for this project was provided by the National Research Foundation (NRF) of South Africa through a doctoral bursary awarded Dr Masamba. It is expected that structure-guided drug discovery for schistosomiasis will be the concluding part the project.”

Dr Masamba and Prof. Trevor Sewell with colleagues collaborating with GCRF_START at the Aaron Klug Centre for Imaging and Analysis at the University of Cape Town. In the picture from left to right: Dr Priscilla Masamba, Dr Jeremy Woodward, Melissa Marx, Dr Mulelu, Dr Philip Venter, Dr Lizelle Lubbe, Professor Trevor Sewell.
Photo Credit: Rebekka Stredwick. ©Diamond Light Source.

About Dr Priscilla Masamba

Born to Congolese parents in the DR Congo, Dr Masamba lived in the UK and Zimbabwe as a child, before moving to South Africa where she matriculated and studied for her first degree in Biological Sciences at Walter Sisulu University, Mthatha. Thereafter, Priscilla joined the Biotechnology and Structural Biology (BSB) Research Group in the Department of Biochemistry and Microbiology at the University of Zululand headed by Prof Abidemi Paul Kappo and registered under his tutelage for a BSc (Hons) degree, followed by an MSc and later a PhD in Biochemistry. Priscilla’s desire is to continue in the path of macromolecular X-ray crystallography of proteins through the NRF Postdoctoral Fellowship in Structural Biology at the University of Johannesburg.

Acknowledgements

Dr Priscilla Masamba extends a special thanks to Dr Brandon Weber (UCT), Dr Phillip Venter (UCT), Kaylene Baron (UCT), and Ndibonani Qokoyi (University of Zululand) who were involved in different ways in the production, purification and crystallisation of the G4LZI3 protein, as well as in data collection.

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.”

Professor Daniel Muturi Wamwangi is Associate Professor and Co-investigator at the School of Physics, University of the Witwatersrand, South Africa.

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).

Structural biology – Improvements in health

The need for health improvement on the African continent continues to be a pressing issue, and START’s emphasis will be on diseases such as HIV-AIDS, malaria, tuberculosis, and African horse sickness that are devastating to human and animal populations. The structural biology strand of START research will support scientists in finding and developing cures by researching and understanding the fundamental molecular structure of certain diseases. Prof. Trevor Sewell from the University of Cape Town explains:

“START will allow us to understand drug targets and cure African diseases. We will establish a collaborating network of seven South African institutions (the Universities of Pretoria, Witwatersrand, North West, Free State, Stellenbosch, Cape Town and the National Institute for Communicable Diseases) that will enable young researchers to boost medical and veterinary research”.

Prof. Trevor Sewell, University of Cape Town

A START project at University of Cape Town led by co-investigator Prof Edward D Sturrock

ACE in complex with the clinically used antihypertensive drug, lisinopril (black sticks; PDB ID: 1O86)

Structural biology of angiotensin converting enzyme and related metalloproteases

Enzymes play important roles in a variety of biological processes in the human body. Angiotensin converting enzyme (ACE) for example, is a metalloprotease which regulates blood pressure and is also involved in scar tissue development (fibrosis). Conditions such as diabetes and tuberculosis can lead to excessive scar tissue formation, which ultimately stops proper organ function. Currently, there is no specific treatment for fibrosis and affected individuals have an average survival period of 2-4 years. Hypertension, on the other hand, is a major risk factor for cardiovascular disease and stroke, which accounted for 15.2 million global deaths in 2016. Our research group, led by Prof Edward Sturrock, is based in the Department of Integrative Biomedical Sciences at the University of Cape Town and has a long-standing interest in ACE and related zinc metalloproteases.

Although ACE inhibitors reduce fibrosis and are widely used for treating hypertension, certain patients experience the life-threatening side-effect of severe swelling below the skin surface of the throat and tongue. With the resources provided by START, we aim to design compounds devoid of this side-effect. Detailed structures of ACE will be solved using X-ray crystallography and cryo-electron microscopy to improve our understanding of how ACE functions and enable the design of antifibrotic and antihypertensive drugs.

START Collaborators – research projects

For information on projects please click on the names below

Stellenbosch University: Professor Erick Strauss and Anton Hamann, post-doc 

Cape Town University, Lauren Arendse

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

Key Global Challenge FACTS – Energy

  • According to the UN, energy is the dominant contributor to climate change, accounting for around 60 per cent of total global greenhouse gas emissions
  • Some 840 million people around the world are still without access to electricity
  • Globally, the UN reports that the renewable energy share of total final energy consumption gradually increased from 16.6 per cent in 2010 to 17.5 per cent in 2016, though much faster change is required to meet climate goals.

Source: UK Sustainable Development Goal 7 (Energy)

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, Professor of Catalytic and Computational Chemistry at Cardiff Catalysis Institute.

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.

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The START of great things!

Visualising the structure of an intact helical filament at close-to-atomic resolution for the first time

“We are seeing critical scientific discoveries and the emergence of a new generation of experts that have resulted directly from our training programmes in advanced methods and the use of synchrotron facilities and tools.” Dr Gwyndaf Evans, START Principal Life Sciences Principal Investigator and Principal beamline scientist on Diamond’s VMXm beamline.

A seminal work of Dr Jeremy Woodward, Dr Andani Mulelu and Angela M.Kirykowicz from the University of Cape Town (UCT), South Africa, has provided novel and exciting insights into the structure and inner workings of nitrilase enzymes with the potential to address key health, food security and environmental challenges within Africa and beyond.

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