Initial steps in the desulfurization of thiophene/Ni(100)-A DFT study

摘要

The desulfurization of thiophene on a Ni(100) surface has been studied using ab initio local-density-functional calculations. The calculations were performed using the Vienna ab initio simulation package (VASP), which is based on a plane wave basis set and PAW potentials.Starting from preadsorbed thiphene on the nickel surface several reaction pathways for the desulfurization of the thiophene molecule mechanism have been investigated: In the optimized reaction path an energetic barrier of 0.71 eV has been found for this reaction step. In addition the influence of a hydrogenation of the molecule after the initial C-S bond cleavage was investigated. Although the hydrogenation is predicted to lower the barrier for the desulfurization to 0.14 eV, the barrier for the hydrogenation itself, 0.98 eV, disfavors this process.A detailed analysis of the structural and electronic properties of the molecule in the corresponding treasition states is presented.