 Hello, I'm John and I'm a chemical engineer. And I'm Simon, a chemist. Together, we're researching ways to replace fossil oil with renewable feedstocks. In this lecture, we will tell you a bit more about why this is important and what we do. Since the Industrial Revolution, fossil resources, namely oil, gas and coal, have transformed the way we live. They've provided us with a stable supply of energy to heat our homes, drive our cars and literally keep the lights on. Fossil fuels are also converted into thousands of chemicals which are used to produce essential products such as plastic packaging, shampoos, medicines, fertilizers and many more. For the last 100 years or so, the supply of fossil fuels has seemed to be inexhaustible, enabling huge advances and improving global standards of living. Unfortunately, this development has come at a huge cost. Fossil-based energy accounts for over 80% of all human-made greenhouse gas emissions, while chemicals contribute an additional 5%. This has led to an accelerating rise in global average temperatures with increasingly severe environmental consequences, including extreme weather, rising sea levels and droughts. Despite significant global efforts to reduce emissions, fossil consumption continues to increase, threatening the future of our planet. Besides climate change, irresponsible extraction of fossil resources continues to cause significant local environmental and social problems, including pollution to ground, air and water. Many chemicals are only used once and can cause long-term damage if disposed incorrectly. Waste plastics, for example, can take hundreds of years to break down and accumulate in oceans where they harm fish, birds and other marine animals. To overcome these challenges, there is an urgent need to reduce our reliance on fossil resources by developing more sustainable and environmentally friendly alternatives. Recent years have seen significant development and investment into renewable energy technologies, particularly wind and solar, to produce carbon-free electricity. This renewable energy is already making an important contribution to reducing CO2 emissions. However, it is more difficult to find sustainable alternatives for fossil-based transportation fuels and chemical feedstocks. Although renewable electricity can be stored in batteries to power electric vehicles, this technology is expensive and cannot provide the same driving range as conventional fuels. Alternatively, renewable electricity can be converted into hydrogen fuel, but safe hydrogen storage and utilization remains challenging. Neither of these technologies are compatible with existing vehicles or can be used directly for chemical production. They also rely on expensive and rare metals which can cause significant environmental harm during extraction and refining. So, how can we continue to produce sustainable fuels and chemicals without using fossil feedstocks? To answer this question, we first need to consider the composition of fossil resources. All fossil fuels are made of hydrocarbons, a wide range of chemical molecules consisting mostly of hydrogen, aka hydro and carbon, together with small amounts of oxygen, sulphur and nitrogen. Depending on the size of a hydrocarbon molecule, fossil fuels can either exist as natural gas, oil or coal, with different ratios of hydrogen to carbon. When we burn these hydrocarbons, we break the chemical bonds between hydrogen and carbon and form new bonds to produce both water and carbon dioxide whilst releasing large amounts of energy. Alternatively, we can chemically transform and separate our fossil-based feedstocks into a small number of platform chemicals, which we can use to produce all the chemicals we know today. To do this, we use very special materials called catalysts, which help to drive reactions in the right direction to ensure we obtain the products that we want. But more about this shortly. First, we need to find an alternative source of more environmentally-friendly hydrocarbons, which we can transform into the renewable fuels and chemicals that we need. Luckily, we don't have to go far. Nature already provides us with vast quantities of bio-based hydrocarbons in the form of plants, animals and other living organisms. Together, this source of renewable material is called biomass and can be harvested and converted to produce renewable chemicals and fuels. Indeed, all the fossil fuels were formed from biomass, which died millions of years ago, and slowly decomposed into the natural gas, oil and coal that we see today. Humans have already been using biomass for food, materials and heating since the dawn of time, but now we need to look for new ways to transform this versatile resource into useful chemicals and fuels. As with fossil feedstocks, these green and sustainable transformations require catalysts. But first, what is a catalyst? Chemical reactions for making essential products or in burning fuels require the breaking and remaking of chemical bonds with the form of consuming energy and the latter producing it. If the energy within the reactant molecule is greater than in the product, then energy is released to its surroundings on reaction. So, external energy isn't required to make it go, which can be thought of as like cycling down a hill, easy and spontaneous. However, while an overall process might be downhill, the bonds of the reactant molecules still require breaking and rearranging. This requires an initial input of energy, which acts as a barrier to molecules reacting and slows the process down. Think of the bike ride. In that while getting from the start to the end is overall gently downhill, you must climb a great big mountain in between. You will only get your destination if you have the motivation, or in the molecules case, sufficient energy. If the barrier is high, it might take you a long time to get there. Worse still, you might not get to your desired destination, but find yourself somewhere else. In a chemical reaction, this is when we make a different product to the one we wanted. So, what we can say is that the route a chemical reaction takes matters. It influences the products we make, and if we can make them at an acceptable speed. While we can increase the speed by increasing the temperature or pressure reaction is done at, this requires energy and cost. We can also make what we want by taking lots of chemical steps to get there, purifying things as we go. Yet this also uses excess energy and wastes molecules along the way. From large industrial reactions to car engines and even biochemical processes in your body, there is a way to make things easier. What if we could find a different route on our bike journey? One that has a small hill to climb. From a molecules perspective, a different way or sequence of making and breaking those bonds. Through a choice of route, we can make reactions go faster to the product we want and with less excess energy. A catalyst is a substance that does this by facilitating a reaction pathway with smaller barriers but in such a way that it is itself not changed in the reaction. It can also be used to change the landscape of the reaction in such a way that we can selectively make the products we want. Catalysts, often in the form of reactive solids, are essential to the efficient running of our fossil-based society. Currently, more than 85% of chemical products use a catalyst somewhere during their manufacture and their role is fundamental to many processes society takes for granted. It's clear that as we transition beyond oil and fossil fuels and move towards a low-carbon dioxide-emitting society, catalysis is an essential technology to make this happen. Yet this isn't as simple as it might seem. As I mentioned earlier, fossil fuels are made from concentrated mixtures of hydrocarbons which can be transformed into a wide range of chemicals. This is achieved by trimming large molecules to a more useful length and selectively adding functional components such as oxygen to their chemical structures. However, the structures of biomass and biobased molecules are very different. They are often diluted in water and contain much higher amounts of oxygen and other impurities. So instead of adding oxygen and other compounds, we must remove them, requiring different types of catalysts to those currently used in fossil processes. In addition, many of existing catalysts are unstable in water and damaged by the impurities contained in biomass. So even if they work, conventional catalysts don't need tend to last a long time when used with biobased feedstocks. Although we can try to improve the stability and activity of existing catalysts for biobased compounds, this approach is slow and inefficient and does not address the underlying challenge. So at Laughborough, we decided to take a step back and develop new types of catalysts which has specifically tailored to the types of molecules and conditions expected from biobased materials. In principle, most solid catalysts consist of multiple different components with only a fraction acting directly as a catalyst. These parts are called the active sites and are the places where the chemistry of catalysis happens. These sites are on the surface of the material where they can grab and destabilise the reacting molecules to promote the desired reaction. Their properties are strongly dependent on their shape, size and composition. The smaller and more exact we can make these active sites, the less material we need to get the job done. This is particularly important when we use expensive and rare precious metals such as gold, platinum or rathenium where we want to make every single atom count. Controlling this dimensionality is essential to creating successful catalysts for an oil-free future. Can we make catalysts that have only the special structures we need? The ultimate example of this would be single atoms or tiny clusters of catalyst with no waste material. However, these active sites can't exist floating in space on their own. They require a second component, the catalyst support. This stabilises the metal particles and stops them from moving about or even leaving the reactor. As well as holding active sites in place, the structure of the support can be used to direct molecules to the active sites and block things that we don't want there. Again, we can play with the dimensionality of the support using 2D sheets like graphene or 1D rods or structures full of tiny holes or pores which give them an enormous internal surface area. For example, one teaspoon of such a porous material contained the area of an entire football field. We are designing new catalysts where we consider both the active site and the catalyst support to enhance the stability, activity and selectivity of our materials. To do this, we first need to obtain a good understanding of what type of catalyst we need by looking at the nanoscale interactions between our reagents and the active sites. We do this both experimentally by monitoring reactions under carefully controlled conditions and through computer simulation where we can predict the interaction of molecules with different types of active sites. We are studying new ways of creating single atom catalysts which provide maximum material efficiency. We then look at the real biobase materials we feed to our process to investigate their composition, impurities and impact on our active sites. This helps us to choose suitable catalyst support materials which are stable under the required reaction conditions and protect the active sites from impurities. This approach requires close collaboration of chemists, chemical engineers and materials scientists which combine the expertise on reaction mechanisms, process scale-up and material design. We are part of a research team at Loughborough University with 7 PhD students and 8 academics investigating the different dimensions of catalyst design. We are using nanomaterials to design efficient and precise catalysts with the right properties to facilitate new green processes such as renewable hydrogen production from biowaste and biobusional production from bioethanol. Using advanced techniques, we can video catalyst as a work to see if we are doing what is expected and then use this information to make better catalysts still. We hope we have shown you how essential catalysts are to moving beyond oil and towards a sustainable and green future. Next time you throw away a plastic bottle, wash your hands or use a pen remember that all these products have been made from chemicals transformed by the help of catalysts. All these products are essential for our standard of living and it is engineers and chemists that ensure that we can keep using them without costing the earth.