Thiophene adsorption studies on clean and hydrogen-preadsorbed MoS₂(100) surface

Abstract

It is known from temperature-programmed desorption studies that the binding energy of thiophene over Mo/γ-Al₂O₃ and Co-Mo/γ-Al₂O₃, hydrodesulfurization catalysts, is lower in the presence of hydrogen. The adsorption of thiophene on clean and hydrogen-adsorbed MoS₂ was modelled using extended Hückel tight binding band structure calculations. In the η¹ adsorption configuration the calculations show a lower binding energy for adsorption on the hydrogen-preadsorbed surface similar to that observed experimentally. The lowering is due to an increased occupancy of the Mo density of states in the presence of hydrogen.