Dynamics (eBook)

‘And now we go to Berlin, where our reporter has met this year’s Nobel Prize winner in chemistry, Gerhard Ertl!

He is a gray-headed 71-years old man, who nowadays walks with a stick through the corridors of the Fritz-Haber Institute in Berlin. Gerhard Ertl, the single chemistry-prize winner of this year, has devoted his life to the chemistry on solid surfaces. And this means quite a lot! Everything from car catalysts, to ozone break down, to production of artificial fertilizer concerns chemistry on solid surfaces.

Professor Ertl far from emphasizing his own excellence, but gladly surface chemistry as such, what it has done, and what it can do. A hundred years ago surface chemists succeeded to trap the nitrogen in our air and to make fertilizer from it. This was a determining factor for the development of Mankind. Without artificial fertilizers, our Earth had not at all been able to feed so many lives.

And now we face new questions of our destiny: The climate and the energy supply. We have to make it without oil. And whether the solution is called solar cells, hydrogen used in fuel cells, or fusion reactors that need extremely endurable walls, so is surface chemistry important also now. “Surface Science should play a major role in the answers to and solutions of the problems of the future",

Ertl concludes.’

I: In one of the pompous old buildings Gerhard Ertl resides, this year’s Nobel Laureate in Chemistry. Since he retired three years ago, he has moved out of his director’s office into Fritz Haber’s old office. He has worked about half days. At least before the message about the Nobel Prize arrived.

E: Before I was a retired professor sitting here at my desk, writing a book and thinking about the development of my topic and my subject. And then the call from Sweden came in. Everything changed. I was overflooded with telephone calls, with emails, with nice mails with requests and invitations.

I: Thinking of what he has done, devoted his life since the sixties to surface chemistry, it is almost remarkable that he can give such a simple and clear picture of what surface chemistry basically is.

E: If you look at a piece of metal or just a solid, then the atoms that are inside are surrounded by nearest neighbors, that means chemical bonds that are saturated. However, if you then cut the solid into two halves, then you get two surfaces, where the outermost atoms are not surrounded by a maximal number of atomic neighbors. That means that they have free valencies that can take part in chemical reactions with atoms or molecules in the surrounding gas, for instance, the air. This is surface chemistry. It is restricted to the topmost atomic layer!

I: In this absolute boundary between, for instance, metal and gas, one is also at the boundary between physics and chemistry. This was what attracted the young GE once. From the beginning he is a physicist, but he has all the time carried along the chemistry interest, which caught him already in his boy’s years, when he made experiments at home.

E: But my mother was not very happy about it, because it was sometimes smelling strangely and sometimes it was exploding. And she was frightened. So I had to refrain myself and to stop that. I went over to physics and started to build radio sets.

I: Then there were physics studies at the university, but the attraction from chemistry was left. And so it became physical chemistry for Ertl, and surface chemistry … Even if he has a lot to say about what good things surface chemistry has done and can do to mankind, Ertl’s own engagement is entirely devoted to pure curiosity.

E: I was always going back to the university, so we never had in mind any applications or happiness of mankind or so. But I think that answering questions is the main task of science, and we persisted for the whole time. And if something comes out of it, which is of use to other ones, that’s fine, but it was not the major motivation.

I: Ertl emphasizes the role of Fritz Haber, Ertl’s predecessor at FHI, about 100 years ago. Haber was certainly scientific leader of the German program with chemical weapons, but this is not what Ertl wants to emphasize but rather that Haber, with the help of surface chemistry, succeeded to produce artificial fertilizers for plants. Today we are used to artificial fertilizers but then it was a challenge to trap nitrogen from the air and transform it into nitrogen in a form that the plants can use. This reaction was necessary to support a growing world population.

E: They found this reaction in the laboratory in 1908 for the first time, and it was immediately taken over by industry, and they developed the first industrial plants, which stood in operation 1913. And in the meantime, the production of ammonia, which is the basis of fertilizer industry, increased continuously, parallel to the increase in world population. Without this Haber–Bosch reaction the world would have looked differently today.

I: This was 50 years before Ertl started his research career. He entered the stage in the sixties, when the situation was quite different from that of Fritz Haber. At this time new techniques became available, not created to answer the questions of the chemists but fully useful it appeared. Ertl started to use them immediately and looked for answers to new questions.

In 1974, at about the same time as ABBA won the European Song Contest, Ertl was at a symposium that just concerned the chemistry behind fertilization. A leading scientist talked about the past 50 years of research in the area.

E: He came to the conclusion that we still don’t know how the nitrogen molecule is activated to get the nitrogen into ammonia. After 50 years! And I went back and told my own students that this is a problem that we should be able to solve now with our techniques. That is how I got interested in that. And a year later or so we knew that the nitrogen first has to be split apart into two nitrogen atoms, which are bonded to the iron surface – the catalyst is made by iron – and which react, in the next step, with hydrogen atoms to make ammonia. The final result is ammonia that gets off the surface into the gas phase.

And when the ammonia plant producers now know how the reaction proceeds in detail, they get better control over their fabrication process. It is very important for them to know what is really going on, they say.

I: Gerhard Ertl considers himself lucky, to have come at the right time to these new techniques and to always have had good coworkers to work with. When I go out into the corridors of the FHI to look for these collaborators, it...