Abstract
The development of PEM electrolysers is closely connected to the discovery of perfluorinated ion-exchange membranes Nafion® from DuPont, and the first PEM electrolyzes were developed in the 1960s by General Electrics. In the beginning, PEM electrolysers were mainly used for oxygen generation in anaerobic environments, but over the past two decades, it has been increasingly used for hydrogen production in the industrial sector. Several companies have already put 1-10 MW-scale systems in the market and 10-100 MW systems are being announced. This chapter provides an overview of the PEM electrolysis technology, including the materials used, stack design, lifetime and performance as well as system configurations and modelling before closing with a summary of recent advances in the field as well as an outlook for future development.