British scientists have discovered that graphene allows protons to pass through and they see the discovery as a breakthrough that could make fuel cells based on hydrogen significantly more efficient in the future.
The graphene structure of carbon atoms, a layer the thickness of a single atom, is known for being impenetrable, but scientists at Manchester University found that, unexpectedly, protons can penetrate the material relatively easily. This mainly happened at higher temperatures and when the graphene was covered with nanoparticles that act as a catalyst, such as platinum.
The property makes graphene potentially useful for use as a membrane in fuel cells. The membrane is a crucial part of such cells: it separates the hydrogen at the anode from the oxygen at the cathode. On the anode side, hydrogen is split into protons and electrons. The membrane has to let the protons through, but the electrons have to go to the cathode via another route, where the resulting electricity can power a motor. In the cathode, the electrons come together with protons to react with oxygen, with water as a residual product.
The researchers also managed to extract hydrogen from moist air with test membranes, describes Manchester University. This could eventually lead to fuel cells that generate electricity based on the outside air. In addition, the invention could lead to methods for extracting hydrogen from the air for storage, for use at a later time. The group is publishing the findings in the scientific journal Nature.