The reversible dissociation of hydrogen molecules and the para -hydrogen conversion

Abstract

An examination has been made of the hypothesis that the rate of the para -hydrogen conversion on tungsten is determined by the rate of condensation of hydrogen molecules into an almost full monolayer of chemisorbed atoms. Using the Peierls equation, and employing parameters consistent with the adsorption isotherm and heat data (in particular an interatomic repulsion energy of NV = 4800 cal/mole), it is shown that the calculated values of absolute rate, activation energy, and pressure dependency are in disagreement with those observed experimentally.