Discovery is sometimes difficult because we tend to be biased. In trying to discover how nature works, we are not sufficiently open-minded to think freely.
The genome is an information code, obviously, but one that was built out of needs that arose through chemical reactions, which in turn corequired a series of processes necessary for life to unfold the way it is at the moment.
—Avelino Corma
Avelino Corma is Professor at the Instituto de Tecnología Química, the Polytechnic University of Valencia, Spain. He earned his doctorate in chemistry in Madrid. His research focuses on heterogeneous catalysis, as basic research and for industrial application. He is an internationally recognized expert in solid acid and bifunctional catalysts for oil refining, petrochemistry, and chemical processes. He has published more than nine hundred research papers and is cited as inventor on more than one hundred patents.
Among the awards he has received are the Ciapetta and Houdry Awards of the North American Catalysis Society, the Gabor A. Somorjai Award for Creative Research in Catalysis from the American Chemical Society, the Royal Society of Chemistry Centenary Prize, the Solvay Pierre-Gilles de Gennes Prize for Science and Industry, the M. Boudart Award on Catalysis from the North American and European Catalysis Societies; the Gold Medal for Chemistry Research Career (2001–2010), the Prince of Asturias Award for Technical & Scientific Research (Spain, 2014), La Grande Médaille de l’Académie des Sciences de France (France, 2011), and the Spiers Memorial Award from the Royal Society of Chemistry (UK, 2016).
Adolfo Plasencia:
Avelino, thanks for having me. You have devoted your whole life to chemistry. Do you think it appropriate to refer to chemistry as being the creative, central science?
Avelino Corma:
Yes. For me, it is something I am passionate about. In a broad sense, chemistry is the discipline that allows me to delve into the knowledge of and the solution to problems in our society.
A.P.:
Albert Einstein said, “Most of the fundamental ideas of science are essentially simple.” Do you think there are still ideas to discover that are at once fundamental and simple, in a chemistry as complex as the one you research in the twenty-first century?
A.C.:
These ideas often seem simple once we already know them, or once they are explained to us; in fact, discovery is sometimes difficult because we tend to be biased. In trying to discover how nature works, we are not sufficiently open-minded to think freely and to tackle new problems without preconceptions. If we were disciplined to do so, we would not take the wrong direction and we would reach newer, more original knowledge.
A.P.:
Avelino, in science, the past, time gone by, was not better. Do you agree with me?
A.C.:
Of course it was not. It was definitely more heroic in the past but not necessarily better. Whatever the case, we are the result of all those researchers and professors, and even anonymous heroes in science who struggled before us so that we could find what we now use as a starting point. And they must be given the credit for that.
A.P.:
You frequently talk about balance. There is a classic balance between basic or fundamental science—science seeking the truth in the long term, with no rush—and applied science, which leads directly to technology, to a specific implementation. How can this be translated to today’s chemistry?
A.C.:
In our work at the Institute of Chemical Technology laboratory, we don’t like making a sharp distinction between basic and applied research. To succeed, you need to make progress in both at the same time. Basic research is essential to increasing our knowledge. It is only through this knowledge that we can access ways and modes of application. But if we focus only on the application we will not be able to discover something that is truly new. Thinking about new hypotheses and testing them experimentally is what leads to creation. And considering these hypotheses and proving them is what satisfaction is all about.
A.P.:
What do you do at your laboratory?
A.C.:
We work in chemistry and, within chemistry, in catalysis. For those who are not familiar with it, catalysis is generated by catalysts. A catalyst is just a material capable of accelerating a reaction and increasing the reaction rate, directing it toward a result, that is, the specific compounds we seek. It is clear that the catalytic process develops at a molecular level, so if we want the process to fulfill its goal, we must work at the molecular level, which means we have to have a molecular design for our catalysts. The ultimate goal would be to attain “molecular recognition.” That is to say, our catalyst should “recognize” the molecule it is to react with in such a way that it could activate only the relevant chemical bonds to transform it into the desired final substance.
A.P.:
Chemistry is also related to a lot more things than people think—to the brain, for instance. In neuroscience, the mind is said to have been generated by an emergence caused by a whole system, by the addition of chemical and electrical reactions.
Is that right? Is chemistry involved in the way our brain works?
A.C.:
Of course. Chemistry is the basis of life. And any process taking place in life has a very high chemical component. If we think about the way you and I are working at this very moment, there is a large system of a chain or cascade of chemical reactions taking place. My talking to you occurs because I activate a number of muscles; this in turn triggers a series of neurons, and all this happens through a series of chemical reactions and electrical impulses. Therefore, chemical reactions make up the very basis of life and make life as we know it today possible.
A.P.:
I’d like to continue on this theme. One of the basic revolutions in life sciences is the genome.
In your view, is the genome more physical or more chemical, more of an “information code”?
A.C.:
I would say it is probably all of these. It is an information code, obviously, but one that was built out of needs that arose through chemical reactions, which in turn corequired a series of processes necessary for life to unfold. If our individual genome is the way it is today, it is because certain chemical reactions took place over a long time, which led to the evolutionary construction of these molecules. Now, these molecules induce other chemical reactions, which allow life to develop at this moment in time.
A.P.:
Going back to your discipline, what approach or pathway is best suited for innovation in today’s complex and very advanced chemistry?
A.C.:
Perhaps one possibility is to be positioned at the interface between disciplines, to be cross-fertilized by other fields such as material science, medicine, and physics. I believe that it is precisely these interfaces that provide new opportunities.
A.P.:
You are a cofounder of the Instituto de Tecnología Química (ITQ, Institute of Chemical Technology), an organization that you have headed and promoted for many years. Today it is a world-reference research center under the umbrella of both CSIC and the Polytechnic University of Valencia. It employs PhD students and researchers from the university where it is based, as well as from other national and international universities. Your main research area at ITQ is catalysis, both in basic and applied chemistry but also in chemical technology. And you also have strong links with companies on several continents. What is the best research approach for an organization like yours that manages to combine basic and applied chemistry and chemical technology, both today and in the near future?
A.C.:
That’s correct. I indeed cofounded the Institute and I was its director for twenty-two years. The current director is Professor Fernando Rey García. As you rightly said, one of the most important activities at ITQ is catalysis, from both a fundamental and applied point of view. This said, the Institute is also very powerful in photochemistry and photocatalysis. In my opinion, the research approach that best combines basic and applied chemistry and chemical technology is one that starts by considering a problem from the point of view of providing new knowledge about nature itself. It seeks to answer fundamental questions about how a particular aspect of nature works. If we are going to deal with a problem of this kind, why not be ambitious and select a problem of fundamental importance? If we could choose, I would pick one that could also give us a solution to a very significant technological problem whose solution is needed or demanded by society. This is how basic and applied science—plus technology, in our case—are combined.
A.P.:
The first decade of the twenty-first century was marked by the powerful emergence onto the global scene of such countries as China, India, and Brazil, causing the demand for energy, fuel, and raw materials to grow dramatically.
How is your chemical science facing this huge and growing demand?
A.C.:
Chemical science, and chemistry in general, progress by trying to make the most of existing finite resources. To produce energy we continue to use fossil fuels. My view is that we will continue using them unless there is an absolutely sensational discovery in the coming twenty years. Therefore, it is our duty to use those energy producers in the most efficient way possible. To do this, we will have to develop fresh methods of extraction, refinery, and transformation. These should allow us, in the field of gas or oil, for example, to derive the maximum amount of fuel—in other words, energy—from the same amount of oil or hydrocarbon. We will therefore need catalysts that can improve the quality of the final products obtained while yielding more from the crude oil at our disposal. Or, in the case of coal, we will need to purify it so that emissions into the air and the environment include the smallest amount of emissions that are incompatible with the environment. That is, on the one hand, we must take advantage of what we have in a more rational way, and on the other, we must develop new energy sources in such a way that they also are economical to use.
In addition, and in relation to new sources of energy, we must make the most of solar power. Sunlight can be used through energy capture in photovoltaic or solar cells. It can also be used to dissociate water into hydrogen and oxygen, with the hydrogen then used as an energy carrier. So we need materials and catalysts. In this area too, we are trying to contribute to general knowledge and, if possible, to technology as well.
We need to get the message through to society that at the end of the day, we are all responsible for the use of energy, and it is an obligation for society to become aware of energy use and to realize that no improvement comes for free. Everything has a price. And we must start considering that price, together with its implications for our comfort. First, we should be able to save energy, to minimize its use. Are we ready to make the most logical decisions? The most logical thing is to start by saving. That is how we should start, in my opinion.
Then we must exploit existing resources in the best possible way and find new sources of energy. However, if we want to be realistic (and in the absence of some exceptional discovery), we have to think that our energy basket is and will be a combination of different power sources, including fossil hydrocarbons, nuclear power, hydraulic, wind, solar energy, and tidal or geothermal energy where possible. But only the first few tend to be within reach for many countries. The sum of them all will provide the total amount of energy that we can use. Hopefully, over time this energy basket will shift in the direction of renewables. That is what we are working on. But at the same time, we must guide, save, and reduce energy consumption.
A.P.:
Regarding hydrogen as an energy carrier, I have heard you say that ultimately an acceptable, positive balance must be reached because the huge expectations about hydrogen a few years ago have not been fulfilled.
A.C.:
Adolfo, the first law of thermodynamics says that to obtain energy, we first need to have energy. The energy balance must be fulfilled. It is always a prerequisite. For us to produce hydrogen, we first need to use energy. If we get it from water, we need to break down the water molecule—and that takes energy. If we want to break it down using electricity generated by means of fossil hydrocarbons, then it’s back to square one. If we want to generate hydrogen from methane, we are still using fossil hydrocarbons. Essentially, what renewable energy source can produce this water dissociation and obtain hydrogen in a renewable way? Wind, solar, geothermal? Basically, we must be realistic; in the current climate it would have to be wind or solar. So, other than these two renewable sources, everything requires fossil hydrocarbons or nuclear power. That’s our choice.
A.P.:
And a price has to be paid for it.
A.C.:
Of course, there is a price to pay. The equation is very simple: decreasing the energy we use by 10 or 15 percent, for example. A 15 percent energy reduction in developed countries with renewable energy, like Spain, would render nuclear power plants unnecessary. But we don’t seem to be willing to reduce our energy consumption by such a figure.
A.P.:
Let’s go back to science, to your passion: chemistry. For science, the study of immensely small things seems to be one of the roads to the future. Condensed matter physicists, such as Pablo Jarillo-Herrero, say that within the scale of a few nanometers, some rules of physics change completely with respect to those that apply to the world as seen by the naked eye.1
Does this apply to chemistry too? What is the difference between chemistry and, for example, physics in the range between 0 and 200 nanometers, an area that you are already investigating?
A.C.:
I believe that is precisely the meeting point of chemistry and physics. They meet in the realm of nanomaterials and smaller particles. They meet from a theoretical point of view: quantum mechanics has been developed by both physicists and chemists, and there is a discipline called chemical physics in which they converge in some ways. The same applies to the preparation of these nanomaterials. In such preparation, chemists use a certain number of techniques and physicists use others. More and more, physicists use techniques from chemistry, and chemists use those of physicists. Differences blur and disciplines come together. As I said, it is at that scale that chemistry and physics meet in such a way that the distinction between them no longer applies.
A.P.:
In one of your recent lectures, a researcher asked you a question about the possibilities of doing certain things with specific molecules. You told him, “Give it up. Matter is the way it is. It will do whatever it has to do and nothing else. You need to adapt to matter. There is no other way. You won't get it to do what it cannot do.” It was something like that, I think.
A.C.:
Yes. There are a few basic principles that must be observed. I always say to my students, before studying your reaction from a kinetic standpoint, you must study the thermodynamics of the process. Thermodynamics tells us what is possible, what is not possible, and under what conditions it is possible. This needs to be taken into account before tackling any problem. Of course, you can always intervene, but if you need to use an enormous amount of energy to intervene in a process, and the performance you get is very low—thermodynamics is king—then the process may not be worth it.
A.P.:
When you imagine the scenario of “nanomatter” and think about physics, generally you think in “static mode.” But if you regard it as chemistry, you’re obliged to think about it as a dynamic scenario, a “film” instead of a “photograph”—something in motion, where things, reactions, happen. For example, I understand that you are coating gold particles by manipulating nanospheres in which the volume of a molecule can be synthesized, and covering them with other smaller molecules in a sort of nanoarchitecture.
Can you already handle matter in sizes that are almost unimaginable? How do you move things at that scale?
A.C.:
In the end, we have to go down to these levels in scale to move away from conventional, known scenarios, to find new possibilities for matter and molecular interactions. If we think about the properties of iron metal, or about an iron, cobalt, platinum, or gold oxide, its properties as metal are already known and they are very well defined. But a most interesting thing happens when one begins to reduce the size of these particles down to dimensions that are close to individual atoms. At that point, iron no longer has the features of a standard metal. Nor has it those of isolated molecules and even isolated atoms. Rather, it has a new behavior which corresponds to what we call nanoparticles and metal clusters.
A.P.:
But what you are describing is a quantum scenario, isn’t it? In the quantum scenario, chemical behavior differs from that in our reality, doesn’t it?
A.C.:
Quantum behavior is also part of the reality we live in. But in this case, that scale allows us to prepare reactive species and certain materials with unusual properties. We wouldn’t have these if we worked with conventional materials, such as those derived from the metal elements that I mentioned, or bulk structures, or insulator atoms. This presents an opportunity to move forward. For this we need knowledge, techniques, and technology, to produce these nanoparticles and clusters in a stable way, because particles don’t “want” to stay in this very small dimension if they have the possibility of joining others to form something bigger. It is a bit like what happens to us in society.
A.P.:
Then is there a “sociology of nanoparticles”?
A.C.:
Of course there is, because the minimum energy state these small particles look for is the one they find when they join together to form larger particles that are more stable, energywise. To study those unusual properties, we have to isolate them. That is what we are trying to do.
A.P.:
And how can you do it materially?
A.C.:
We are creating nanoreactors with zeolites to confine the nanoparticles and cause them to react selectively. Here we have to think about another type of nonconventional interaction. Take, for example weak interactions, which we call van der Waals interactions. They require little energy and they are extremely important because they stabilize reaction intermediates. Besides, since nanoparticles are confined to the pores inside nanoreactors, they are subject to very strong electric fields. As a result, they are “pre-activated,” which would not happen in the medium if they were not confined. So interactions occur at the molecular scale, and with relatively long lifetimes, much longer than when normal particles are in much bigger places.
A.P.:
Described this way, these materials seem abstract, but they have an enormous impact in the real world, don’t they?
A.C.:
Yes, they do. Without such porous nanomaterials, like zeolites, industries such as fine chemistry or oil refining would not exist as we know them today. Approximately 35 or 40 percent of the petrol and diesel used in the world are obtained through these nanomaterials. What is more, this kind of fuel has a better quality and octane rating—and better environmental properties too. It has less benzene and fewer, more inert olefins. We have also shifted from getting a 30 percent useful product out of each barrel of oil to 90 percent nowadays. Consequently, we are being at least three times more efficient in the use of natural energy resources. This is key from the point of view of preserving our raw materials and energy, which are finite.
A.P.:
Let’s now move from the nanoscopic scale to the biggest things in our planetary scale. One of the concerns in today’s world is understanding the planet as a finite whole, with limits, as something to protect. In this respect, green chemistry is providing solutions to many people’s needs and at the same time respecting the planet’s ecosystems. Given this, do you think people appreciate it enough? In everyday life, they enjoy thousands of solutions offered by chemistry but also criticize it?
A.C.:
Quite frequently, people criticize what they do not know, or their criticism is not sufficiently based on knowledge. In the case of chemistry, I think some things, such as pesticides, have had a more negative impact. It is generally believed that if these pesticides are released into the air, they will come into contact with people or with foodstuffs. People get worried about gases from car exhaust pipes and the like. However, when they criticize, they forget that it was chemistry and catalysis in particular that led to the discovery and allowed the synthesis of ammonia, without which agriculture would not have developed as it did, and as a result, the planet’s population would not had grown as it did. Nor would we have had the yield per hectare that we can achieve nowadays, enabling us to feed so many more people. Chemistry made this possible. And whenever we have crops, we have pests.
Although we tend to say that any previous era is superior, that is not the case. For example, lead hydrogen arsenate was used for pest control for many years. It would be terrible to use it today. Chemistry has produced new molecules that are more and more specific to the insects that you want to control and less harmful to superior species. Besides this, chemistry has been capable of developing alternative pest control methods, such as pheromones, in which chemical ecology research, for example, has made interesting progress: chemistry can synthesize the sexual pheromones of insects and selectively achieve the elimination of these insects without harming other species, or human beings, of course.
We usually talk about gas emissions from either mobile sources or stationary sources. But we seem to forget that we all want to continue using our car. And that it was chemistry and catalysis that improved the quality of fuels and eliminated emissions from fixed physical sources in industries. Thanks to chemistry and catalysis, they have been minimized by three orders of magnitude and almost reach zero levels today. Therefore, when we talk about chemistry, first we must understand that today’s standard of living or the fact that many diseases can be now cured is the result of chemistry. And in those cases where our activity generates products that can also be harmful to us, it is that same chemistry that is trying, successfully in many cases, to eliminate such products by transforming them into substances that are not harmful to the environment.
A.P.:
Cutting-edge chemistry also guarantees excitement, doesn’t it?
A.C.:
The only thing I can tell you is that one of the biggest satisfactions is to make a hypothesis about how to solve a fundamental scientific problem and finally reach a solution that confirms the hypothesis. That is immensely satisfying. I don’t know what I could compare it to—something big, for sure, particularly if you have a passion for creation and discovery.
I would say that science and technology are the answer to our current problems and those we will soon have to face and which often make us pessimistic about our future. I believe these problems have a solution from a basis of science and technology. Chemistry is a discipline that is fundamental specifically to the development of science and technology, and therefore also to the sustainable development of our world.
A.P.:
Thank you very much. It has been a pleasure. I hope you continue being so enthusiastic about chemistry.
A.C.:
I hope so too!