Exploring haem-based alternatives for oxygen reduction catalysis in fuel cells - A status report of our first principles calculations

For hydrogen fuel cells to become commercially viable, an alternative catalyst to platinum surfaces that is both efficient and affordable must be discovered. We consider haem and haem derivatives as potentials substitutes. In this paper, we discuss the oxygen reduction reaction on both the platinum surface and on haem. We then introduce our suggestions based on density-functional studies on how to improve haem's oxygen-reduction capabilities, which can be summarized as follows: inducing the singlet state, inducing side-on interaction, mimicking cytochrome c oxidase by adding a copper-imidazole complex, using platinum deposited on tin porphyrin instead of haem, and using oxomolybdenum porphyrin instead of haem. We shall focus on the last three methods because of their experimental practicability.