The Adsorption and Desorption of Dibenzyl Disulfide and Dibenzyl Sulfide on Steel

Abstract
The adsorption of dibenzyl disulfide and dibenzyl monosulfide from hexadecane on a chromium steel has been studied as a function of time, temperature, additive concentration and stirring rate. Radioisotopic labelling with 35S and 14C has been used to elucidate aspects of the adsorption behavior. The reaction is in two stages, physical adsorption which follows Langmuir kinetics up to θ ˜ 0.9, and then chemisorption to monolayer sulfurisation. The desorption of the additive has also been studied as a function of time and temperature, from θ ˜ 0.8. Again Langmuir kinetics is observed. The enthalpy and entropy of activation for these processes have been calculated.