Adsorption phenomena of a mechanically-alloyed mixture 2Mg+Ni

Abstract

The nitrogen adsorption phenomena of a mechanically-alloyed mixture were studied after activation. The specific surface area of the activated mixture was 2.72 m~'g -t. The adsorption and desorption isotherms of the activated mixture were obtained. The adsorption isotherm was similar to type II among the five types of isotherms classified by BDDT. Its hysteresis curve had a form of type B among the de Boer's five types of hysteresis. Desorption pore-size analysis showed that the activated mixture had only a few mesopores whose diameters were 20-80/~ around. The shapes of adsorption isotherm and hysteresis curve, the desorption pore-size distribution analysis and SEM micrographs showed that, the particles of the activated mixture were nonporous and they had only a few mesopores. The average adsorption rates of the activated mixture showed a first-order dependence on the nitrogen pressure at 77 K.