الفهرس 
INTRODUCTION& LITERATURE REVIEWOnly 14 pages are availabe for public view
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Abstract
This work has been carried out to investigate the
electrochemical behavior of Mo and Zr metals in aqueous solutions
of different pH covering the acidic, neutral and basic ranges. The
cathodic hydrogen evolution on these metals in acidic and basic
solutions was also investigated. Conventional electrochemical
techniques such as open-circuit potential measurements, cyclic
voltammetry, potentiodynamic polarization and electrochemical
impedance spectroscopy (EIS) were used. The results have shown
that the corrosion and passivation behaviors of these metals are pH
dependent over the whole pH range. The steady state potential of
the molybdenum electrode is a linear function of the solution pH
with a slope of ≈ 0.057 V/pH, which means that the electrode can be
used as pH indicator electrode for aqueous solutions. The surface of
these metals is always covered by a passive film. The stability of
passive film on Mo and Zr in acidic solutions is more than that in
neutral and basic solutions. The results have shown that the Mo
electrode can be considered as a promising cathode for the hydrogen
evolution reaction. It was emphasized that, Mo is even better than Pt
and Zr in acids and alkali solutions and can be used continuously for
at least 24 h for hydrogen evolution without any deterioration.