'Science Can Only Be Done Collaboratively'

On March 19, Academician and Professor Andrey Yaroslavtsev, Head of the Joint Department of Inorganic Chemistry and Material Science with the RAS Kurnakov Institute of General and Inorganic Chemistry, celebrated his birthday. To mark the occasion, he spoke with the HSE News Service about protons, membranes, and other areas of his research.

Hammering Nails, Electrical Conductivity in Solids, and What Protons Have in Common with the Proletariat

Scientists sometimes joke that they satisfy their curiosity at the expense of the state. In reality, this is more a stereotype held by people far removed from science. However, it seems to me that the vast majority of the public understands that this is not the case. My son once convinced me of this. When one begins studying chemistry, it is usually the beauty of the subject that attracts them first. We look with curiosity at test tubes, beakers, and flasks, whose contents change colour when mixed, form precipitates, or begin to release gas… At this early stage, chemistry fascinated me not only with its intellectual challenges but also with these striking effects. Once I brought my four-year-old son to my workplace at Lomonosov Moscow State University, which was hosting a New Year’s party for children. Naturally, I wanted to introduce him to the beauty and excitement of chemistry. I sat him on a chair and put on a small show, demonstrating solutions that changed colour in striking ways. When I asked whether he liked it, he said, 'Yes. Now tell me, where do you work?' 'Here,' I replied. 'And what do you do?' he asked. 'I just showed you,' I said. He looked at me incredulously: 'You’re joking again,' he said, and added, 'Work means hammering nails.'

Although I do joke a lot, my son was certainly right. In reality, I was not doing exactly what I had shown him. At the time, I was studying solids. More precisely, I was synthesising compounds in which certain groups possess internal mobility. Why do we call solids 'solid'? Because they are generally resistant to deformation, even when force is applied. The reason is that in solids, atoms occupy fixed positions and moving them requires a great deal of energy. To deform a solid, atoms must shift into positions that are already occupied, which is impossible due to the extremely low compressibility of solids—placing two atoms where only one can fit is unrealistic, even for a very short time. Nevertheless, some mobility does exist in solids. It is associated with defects—most commonly vacancies, or positions where atoms are missing. In ordinary solids, such defects are rare, which is why they are so resistant to deformation. However, in certain materials, atomic movement can be relatively fast and can be observed using specialised instruments.

When I began my research at university, I was advised to study nuclear magnetic resonance. Today it is a well-known, highly advanced, and largely analytical method, but at that time it was still in its early stages and looked quite different. We used it to investigate internal mobility in solids. It was most convenient to observe this mobility in protons, which produce the strongest signal in nuclear magnetic resonance. Later, I decided that we needed an alternative approach that would allow us to quantify proton motion. This approach was based on measuring proton conductivity.

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In fact, proton conduction had already been discovered before I began my scientific career. I would say that the early papers by its first researchers conveyed a certain sense of euphoria: they believed that by studying and improving solid electrolytes, it would soon be possible to achieve proton transfer as rapid as the flow of electrons in many metals—conductors that are now widely used in energy applications. The reasoning seemed straightforward. The mobility of atoms is limited primarily by their size—it is difficult for them to pass through the tiny spaces between other atoms. A proton, like an electron, is an elementary particle of extremely small size. Therefore, it was logical to assume that, like an electron, a proton could be made to move rapidly, at least in certain solids. Unfortunately, these expectations were not realised. Everything around us is made of molecules, which in turn are composed of atoms, each consisting of a nucleus surrounded by electrons. The size of an atom is determined primarily by its electron cloud, which orbits the nucleus and occupies nearly the entire atomic volume. When a particle moves through a solid, it primarily 'feels' the electron clouds, which are negatively charged. A negatively charged electron is repelled by these clouds and can easily navigate around obstacles, naturally finding the path of least resistance. A positively charged proton, on the other hand, is attracted to the electron clouds and tends to become trapped within them. I could liken protons to the proletariat, referring to the famous phrase from The Communist Manifesto by Marx and Engels: 'The proletarians have nothing to lose but their chains.' Unlike other atoms, a proton has only one electron, which it can lose quite easily. After that, it truly has nothing left to lose. By comparison, it is even easier to remove an electron from a sodium atom—but the resulting sodium ion still retains ten other electrons, so the lost one is not missed as much. But a proton has only one electron, and it has nothing left to lose except its 'chains.' That is why it clings tenaciously to the electron clouds of electronegative atoms, hoping to reclaim what it has lost. Protons typically reside within these clouds, bound to them by their 'chains.' In this respect, a proton is fundamentally different from other ions, and its movement within a solid does not occur in the same way. Rather than 'jumping,' it moves in two stages: first through the rotation of the atomic group to which it is attached, and then by transferring from one group to another. This distinctive behaviour made the study of proton transfer in solids particularly fascinating.

But every scientist aims not only to explore what is fascinating but also to achieve something beneficial for humanity. Proton transfer in solids underpins the processes essential to hydrogen energy—and at the beginning of this decade, Russia, as well as several other advanced countries, launched programmes to develop this technology. Naturally, producing useful materials requires a great deal of hard work.

On Energy and Security

Of course, compared with the scientists of the past, our fields of interest are much narrower. Diogenes, sitting in his barrel, pondered everything. Our famous compatriot Mikhail Lomonosov engaged simultaneously in chemistry, physics, and mathematics, while also writing poetry. For modern scientists, however, this is unthinkable—each of us works within a relatively narrow, specialised field. My interests are not that diverse either, but proton-conducting materials are not the only focus of our research. Our laboratory works in several areas simultaneously: membranes, lithium-ionics, sensors, and hydrogen production. In fact, these areas often overlap, and hydrogen energy and lithium-ionics are developing in parallel—sometimes even competing with each other—although each occupies its own distinct niche.

To begin with, the creation of nearly everything we use is almost always based on a new material that a researcher has developed while discovering a unique property previously unavailable to anyone. The materials scientist then works, together with other scientists and engineers, to determine how this property can be enhanced and applied. As a result, the availability of this new material sets in motion a chain of development efforts that lead to new devices, vehicles, buildings, and countless other objects in the material world, all of which are rapidly evolving and improving each year.

The world of modern technology is unimaginable without lithium-ion batteries. In recent years, considerable attention has been devoted to the development of lithium-ion technology, both in our country and abroad. Energy is one of humanity’s oldest products and remains one of the most sought-after resources. However, energy production is closely linked to environmental pollution. Burning fossil fuels releases not only carbon dioxide, which has received much attention in recent years, but also nitrogen oxides, sulphur compounds, and products of incomplete combustion, which can be even more harmful. For the first time in history, humanity is considering a shift in energy sources—not primarily for greater efficiency or economic gain but for the sake of environmental sustainability. Environmental concerns are driving the shift from oil and gasoline to renewable energy sources—solar, wind, and hydroelectric power. However, their use is limited by factors such as cyclicity, in the case of the sun, or variability, as with the wind. Clearly, we need energy both day and night, but solar energy, for example, is only available during daylight hours. Moreover, in our latitudes, the sun provides 5–10 times more energy in summer than in winter, when energy demand remains as high. Similarly, nuclear power plants cannot simply be shut down at night, even when energy demand drops. Thus, efficient use of these energy sources requires integration with energy storage systems.

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The concept of lithium-ion batteries emerged in 1970, and life without them has become unimaginable since the beginning of the 21st century. They power our mobile phones, computers, wireless devices, and the most advanced car models. Currently, at the initiative of Rosatom, or more precisely, its TVEL Fuel Company, two gigafactories for producing these storage systems are under construction in Russia. But every year, demand grows for higher-capacity, energy-dense batteries, and we also need to make them safer. Achieving this requires new cathode and anode materials, as well as improved electrolytes, capable of turning these goals into reality. Our laboratory at the Kurnakov Institute of General and Inorganic Chemistry focuses on developing such materials to make batteries both more energy-dense and as safe as possible.

The Beauty of Membrane Catalysis

While they can easily smooth out daily energy fluctuations, lithium-ion batteries are far less effective at handling seasonal variations, such as when the sun provides much less energy in winter than in the bright summer months. Unfortunately, batteries also experience self-discharge. Although this process is relatively slow, the losses can be significant, and for long-term energy storage, hydrogen will undoubtedly play a dominant role. Hydrogen produced in summer and stored in cylinders or alloys can remain in reserve until it is needed. The first wave of interest in hydrogen energy emerged in the 1950s, and today that interest is rising once again. In 2020, Russia adopted a programme for the development of hydrogen energy. True, due to understandable circumstances, progress has been slower than we would like, but I hope that with economic stabilisation, the programme will continue to advance.

Part of our work focuses on hydrogen production. One of the most promising approaches is membrane catalysis. Hydrogen produced from natural gas using high-temperature processes, while relatively easy to obtain, is quite 'dirty.' The products of this reaction include not only hydrogen and carbon dioxide, but also carbon monoxide—an even more hazardous compound. This is problematic for many reasons, and not only because carbon monoxide is toxic to humans. More importantly, it also damages fuel cell catalysts. Even small amounts of CO in hydrogen reduce the catalysts’ efficiency, leading to lower electricity output. Various methods exist to purify hydrogen. It is worth highlighting membrane catalysis, which allows hydrogen production and purification to be combined. This process was discovered by the late Russian scientist Vladimir Gryaznov, who once led a laboratory at the Institute of Petrochemical Synthesis. This is another focus of our work. By developing new types of membranes and optimising catalysts, we can produce two streams at the reactor outlet: absolutely pure hydrogen, and hydrogen containing high levels of CO and CO₂ impurities, which can be used, for example, in chemical synthesis.

The Science of Membranes

The hydrogen produced is then converted into energy in highly efficient devices known as fuel cells. At the heart of a fuel cell lies a proton-conducting membrane. Membranes represent another branch of chemistry in which we are actively involved. Russia has many outstanding scientists working in this field, forming a membrane research community. I love this science, and I deeply value all those with whom we collaborate to create and advance new membranes and membrane technologies. Unfortunately, for a long time, Russian researchers rarely focused on synthesising new ion-exchange membranes, instead relying mostly on modifications of commercial materials and studying processes involving them. However, in recent years, we have begun developing methods for membrane synthesis and have since made significant progress in this area. Our membrane materials have properties comparable to expensive perfluorinated membranes, which are considered the benchmark for their combination of characteristics, but unlike them, ours are far more affordable. While membrane materials may not capture public attention like lithium-ion batteries, membrane science has always been—and continues to be—at the forefront of our industry. Membranes are widely used across diverse applications, from energy and water treatment to the membrane catalysis I mentioned earlier.

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I consider myself fortunate to have many scientific interests, given that a career in science is always a mix of small successes and failures. Naturally, it is preferable to have more successes; otherwise, work becomes less rewarding. Fortunately, we have been making progress because we carefully consider which direction to pursue and how to accomplish our goals. I want to emphasise the word 'we,' because chemistry is a practical and collaborative science. Everything we accomplish is done together with our colleagues. I am working alongside many talented scientists, including my former students from the Higher Chemical College, Moscow State University, and now HSE University. We introduce students to research from their first year, ensuring they gain experience in science at the highest level. Our goal is for them to see how fascinating and beneficial to society chemistry can be, to fall in love with the subject, and by the time they defend their degree, to share the same passion for our science that I do. We also make sure they have a solid record of publications, which is essential for pursuing a successful career in research.

But perhaps most of all, I am grateful to science for the wonderful friends and colleagues across our vast country with whom I collaborate and discuss both scientific and related issues in education and innovation.

March 19