SmallTalks "How to make Hydrogen, and Why"

Abstract 

Hydrogen is the most abundant element in the universe and is the power behind the light of the sun. But for a hydrogen economy, we speak of a humbler reaction: converting water into hydrogen and oxygen using electricity and reversing that process. In this way we can use hydrogen to store electricity, as well as for many other uses. But how do we split water? A proton exchange membrane electrolyzer uses rare earth catalysts to do this at temperatures below 100 C, which allows us to keep the water in liquid form. But challenges remain: the catalyst is expensive and rare and so very little should be used, and between the solid electrodes, the liquid water and the gaseous hydrogen and oxygen adopt many different phases must interact on a small scale to achieve good results with few losses!