“…It has been reported before that the electro-catalytic active phase is attributed to the presence of over saturated and nanocrystalline FCC solid solution of Mo into Ni [1], however the basic reasons for having such good properties are, in fact, still unknown. By the other hand, it has also been reported that potentiodynamic polarization analysis conÿrmed that microstructural factors such as metastability, galvanic couples and particle size distribution on these electrodes are required for e ective hydrogen gas production [2,3,7,8]. In spite of this, there are no reports concerning electrochemical studies carried-out in structures close to thermodynamic equilibrium.…”