So hello everybody, my name is Berim Plitka, I'm a professor of organic chemistry at Stuttgart University. And what I would like to talk today about is what we call hydrogen on demand.

What do we mean with hydrogen on demand? So hydrogen is supposed to be an energy carrier of the future. Hydrogen reacts with oxygen according to the general equation as shown here. So it reacts with oxygen in a very violent way to form water plus energy as a product.

So if you do that all in one pot, this is like an explosion. But if you have the hydrogen and the oxygen in separate cases and then you connect them with a cable, you can let the electrons that are floating from hydrogen to the oxygen, you can use them to go through, let's say, a little engine, etc.

And this is what we call a fuel cell. So fuel cells produce water as a side product and they use the energy in order to, for example, drive a car or make a car driving. And in order to showcase that, Susanna Rommel, one of my PhD students,

she prepared an experiment and she prepared a little car and she wants to demonstrate how that is. So Susanna, go ahead. So we want to show how a hydrogen fuel cell works at this model car. It consists of a reversible hydrogen fuel cell and two gas tanks.

If you connect it to an energy source, hydrogen gas and oxygen gas is produced. If the other way around you connect it to an engine, the car runs. So in order to get that system to work in a mobile device, we need to have a system that is able to store hydrogen in a safe way and to generate hydrogen on demand.

That means if we press the pedal on the car, we really want the car to go. And what we try to do is, in this case, we try to use silanes. Silanes has one hydrogen donor and methanol has the other hydrogen donor. So two different parts of hydrogen that are going together to give hydrogen plus silicate, siloxane.

So that gives us H2 and we need a catalyst for that. And we can have up to three or even four hydrogens on the silicon. That means we have a very small molecule consisting of a high amount of hydrogen, active hydrogen.

And we have another molecule, very small, consisting of a lot of hydrogen. We can let them react and we can get here hydrogen within seconds on demand. This is a new type of catalyst. It's based on iron as an earth-abundant metal. It's non-toxic and inexpensive. And Susanna is going to present how easy this setup is and how much hydrogen you can produce within just seconds.

So, Susanna, I think we go to the laboratory now. Thank you very much. Here I will show you the hydrogen on demand experiment. I prepared a Schlenk tube with a mixture of methanol, the catalyst and the MIP, which acts as a base.

Upon addition of the silane, three equivalents of hydrogen will be released. We collect the hydrogen in this inverted measuring cylinder. This is the iron hydride catalyst. It's an iron catalyst with a bisphosphane ligand and an hydride.

The structure of the complex consists of an iron core with a hydrogen ligand as well as a CO and NO ligand.

The iron core and the hydride as well as a bisphosphane bridge. With such a small amount of methanol and silane, we can produce over 200 milliliters of pure hydrogen gas.

This corresponds to a turnover number of 600,000 turnovers per hour per SIH point.

Here you can see the hydrogen fuel cell car, which we saw earlier in the lecture hall. I prepared a mixture of methanol, the MIP and the catalyst. If I connect the engine right now to the fuel cell, the car can drive.

Upon addition of the silane, the car can continue driving. So hello everybody again. We are back in the lecture hall and I hope Susanna could show you that the hydrogen on demand technology can really develop a defined amount of hydrogen within a very short time frame.

So what's left to do and what is needed in order to become a really practical system? Well we can make hydrogen and the hydrogen becomes water in the fuel cell. That's fine. But what we need is also to regenerate the silicate that is formed. So we have stoichiometric amounts of waste and it would be nice if we could

get this stuff to be recycled to a silane by uptaking either hydrogen or hydrogen donor. So that's what's left behind. We need a catalyst that is able to really cleave the strong silicon oxygen bond. If we can make that system to work, we have a charging process and we have hydrogen on demand.

Teach this charging process and that means we can recycle all the silicon waste and that is much better for the environmental purpose. Thank you very much.