Proton Exchange Membrane water electrolysis

Electrolysis of water produces high-purity hydrogen and oxygen, traditionally used in various industrial sectors such as the food industry, the semiconductor industry, and space and underwater applications. In recent decades, changes in the energy landscape and the need to reduce greenhouse gas emissions have led to renewed interest in the production of electrolytic hydrogen (energy carrier) from renewable energy sources. Despite the still high investment cost due to the use of precious metal-based electrocatalysts and fluorinated ionomers, acid polymer membrane technology (better known by the acronym PEM, which stands for "Proton-Exchange Membrane" or "Polymer Electrolyte Membrane") offers significant advantages over the standard alkaline technology. In particular, the absence of corrosive liquid electrolyte makes it possible to design reliable electrolysers that operate in transient mode under high pressure or even pressure differential, at high current density and with high energy efficiency. The aim of this article is to provide a detailed analysis of the operation and performance of PEM electrolysers, while exploring the technological and economic challenges associated with this technology. This work is part of a technical and economic context in which water electrolysis is seen as an essential lever for the production of green hydrogen, in line with current energy policies aimed at reducing greenhouse gas emissions. Through an exploration of the theoretical foundations, key components, auxiliary features, and performance, this article aims to provide industrial and scientific stakeholders with a clear understanding of the opportunities and obstacles associated with this clean hydrogen production technology.