ELECTROCATALYTIC AND SORPTIVE PROPERTIES OF ELECTRODES BASED ON SUBSTITUTED ALLOYS OF THE AB(5) TYPE

Electrocatalytic activities of the electrode materials based on LaNi5, LaNi2.5Co2.5, LaNi2.5Co2.4Mn0.1, La0.8Ce0.2Ni2Co3, La0.7Nb0.3Ni2.5Co2 .4Cr0.1, MmNi(3.5)Co(0.7)Al(0.8), and Mm(0.5)La(0.5)Ni(2)Co(3) with a Cu binder in the hydrogen evolution reaction in a 1 M NaOH solution ar e compared. The exchange current densities are calculated, specificall y, (0.8-4)x10(-6) A cm(-2). The changes in the enthalpy (-34 and -42 k JM(-1)) and the entropy (-107 and -122 J M(-1) K-1) intrinsic to the f ormation of the La0.8Ce0.2Ni2Co3 and MmNi(3.5)Co(0.7)Al(0.8) hydrides, respectively, are calculated on the basis of the equilibrium charging curves measured in the temperature range 278-323 K.