The decentralized production of hydrogen as a renewable energy vector targets large markets and potential applications: mobility, electricity and fixed heat generation, electricity storage in the form of gas. Hydrogen is today in France and in the industrialized countries an emerging industrial sector, leading to an increasing development of electrolyzers. The study of the behaviour of grade 2 titanium used in these electrolyzers for hydrogen production, using a characterization of parts by Scanning Electron Microscopy (SEM), surface analysis by Glow Discharge Optical Emission Spectrometry (GDOES) demonstrating the hydrogen diffusion in titanium, and electrochemical measurements, will make it possible to understand and interpret the mechanisms that caused degradation after 5000 h of operation and to validate the choice of grade 2 titanium. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.