Hydrogen adsorption on metals

Chemisorption. Chemisorption involves heats of adsorption which are large as compared to the heat of van der Waal s adsorption. The term chemisorption implies formation of semi-chemical bonds of the adsorbed gas with the solid surface. Chemisorption may be a process involving measurable activation energy—that is, a measurable rate of adsorption and a measurable temperature coefficient of rate of adsorption. As in the case of hydrogen adsorption on metals, chemisorption may have no measurable rate of adsorption, the adsorption being essentially instantaneous. 

Figure 5.26. Hydrogen adsorption on metal—sulfur pairs. Adapted from A. Travert et al.l" l.

Hydrogen Adsorption on Metal Organic Framework Materials for Storage Applications... 

Concerning hydrogen adsorption on metallic surfaces, novel relationships (Equations [17.10] and [17.11]) have been formulated in order to evaluate the decrease of hydrogen permeance due to the inhibition of gases such as CO. These new relationships, unlike those reported in the literature, permit a direct and simple correlation between the decrease of the hydrogen permeance and the adsorption of the gas molecules on alloy surface system. The validation of these relationships is in progress. 

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