The objective of this project is to take into account the mechanical constraints formed by diffusion of hydrogen or tritium in watertight palladium alloy cathode. To know the origin of these, it was necessary to discriminating the damaging effects encountered. Effectively, hydrogen and isotope induce deformation, embrittlement, stress corrosion cracking and cathodic corrosion in different regions of cathode. Palladium can be alloyed with silver or yttrium to favourably increase diffusion and reduce these constraints. Effects of electrochemical factors, temperature, cathode structure, adsorbed transient complex of palladium and porous material support are given to estimate and to limit possible damage.
Keywords: cathode; diffusion; electrolyzer; hydrogen; palladium alloy; stress corrosion cracking; tritium.