Man-made fuel cells have a bad energy-efficiency, i.e. they waste two thirds of the energy as heat when they convert hydrogen to electrical energy. Moreover, they need expensive palladium-based catalysts because all the other catalysts are irreversibly poisoned by molecules in ambient air. Hydrogenases that are Nature’s fuel cells convert chemical energy very efficiently into electrical energy, and they do that with cheap iron oxide-based catalysts. We want to find out if we can manufacture a fuel cell that is as efficient as Nature’s fuel cells, and that uses a cheap catalyst.
That is important for society, because regenerative electrical energy is generated when the wind blows or when the sun shines, but two thirds of that energy is lost, when stored with the help of a state-of-the-art fuel cell. Batteries are much more efficient in storing electrical energy, and by now fuel costs for an electrical car are cheaper than costs for diesel fuel because also a diesel engine wastes 70% of the chemical energy that drives the car. But batteries have a problem with their energy-density: electric cars are quite heavy due to their battery, which is even worse in a truck, a ship, an airplane, or when storing energy from a wind park.
An energy-efficient fuel cell would solve these problems: if combined with a small battery an energy efficient fuel cell would outperform a gasoline powered car or airplane.
Building a fuel cell that mimics Nature’s principles is difficult, though. Energy converting enzymes all use the same basic trick: similar to a marble run, they fast lead electrons down a predetermined pathway of redox centres, and, thereby, prevent electrons from recombining with their left-behind proton which would dissipate the electron’s energy as heat.
We use a recently invented multi material nano3D printer to print such layers as nanostacks. Thereby, we want to do materials evolution: printing many different nanostack variants, and selecting improved solar cells or fuel cells.
