A significant part of the costs of popular polymer electrolyte membrane (PEM) electrolysers is the cost of the rare metals required, such as iridium, platinum or gold.
Korean researchers have discovered they can uniformly coat the electrode with iron oxide, which has low electrical conductivity, and then convert the iron oxide to iron nitride to increase its conductivity. Then they coat the iron oxide with a very thin layer of iridium, using about 10% of iridium currently used in PEM technology. This will significantly reduce the cost of the electrolyser, while apparently maintaining a similar performance.