KINETIC-PROPERTIES OF THE TI-NI INTERMETALLIC PHASES AND ALLOYS FOR HYDROGEN EVOLUTION

The kinetics and mechanism of hydrogen evolution at Ti-Ni alloy electr odes prepared by are-melting and mechanical alloying methods has been studied by means of AC impedance spectrum measurements. The electrode, prepared by mechanical alloying (porous electrode), after activation in a 10% HF solution, is very active despite its large Tafel slope. Th e SEM studies show a formation of deep pores on the electrode surface. The rate constants of the forward and backward reactions of the corre sponding steps were estimated by a nonlinear fitting method. It has be en found that the overall reaction proceeds through a Volmer-Heyrovsky mechanism. (C) 1997 Elsevier Science S.A.