Stanovení velikosti specifického povrchu kobaltu
Klíčová slova:
chemisorpce vodíku na kobaltu, specifický povrch kobaltu, stupeň redukce, povrchová hustota atomů kobaltuAbstrakt
The article gives a review on measurements of cobalt surface area (SgCo) by a method of dissociative hydrogen chemisorption which is a reversible process. It is therefore suitable to use techniques which enable one to determine amounts of both reversibly and irreversibly chemisorbed entities. This requirement is fulfilled with static techniques, the dynamic temperature desorption technique and the recently described technique of dynamic hydrogen-deuterium exchange. The precision of the measurements is influenced by the following critically and systematically discussed factors: the extent of reduction to cobalt metal, the surface site density of cobalt atoms and their allotropic modification, the occurrence and stabilization conditions of high temperature face-centered-cubic cobalt under its transformation temperature t = 421.5 °C.