Aray Yosslen, Rodríguez Jesús, Coll Santiago, Rodríguez-Arias Eloy Nouel, Vega David
Centro de Química, IVIC, Apartado 21827, Caracas 1020 A, Venezuela.
J Phys Chem B. 2005 Dec 15;109(49):23564-70. doi: 10.1021/jp054097t.
The energy of formation and the Lewis acid strength of sulfur vacancies or coordinative unsaturated sites on the MoS2 edges were studied using density functional theory for periodic systems and an electrostatic potential-based methodology. The results suggest that the more energetically favorable sites are located on the sulfur edges; however, their Lewis acid strength is considerably smaller than the site acidity at the molybdenum edges. The acid strength for the reported most hydrodesulfurization active site of RuS2 was also determined. In general, the Lewis acid for the site on RuS2 is 100% smaller than the sites on the Mo edges and around 20% larger than the most favorable site on the S edges of MoS2. Binding of the pyridine molecule in the eta1 adsorption configuration on the considered sites has corroborated the trend of Lewis acidity suggested by the electrostatic potential methodology.
利用针对周期性体系的密度泛函理论和基于静电势的方法，研究了二硫化钼边缘硫空位或配位不饱和位点的形成能和路易斯酸强度。结果表明，能量上更有利的位点位于硫边缘；然而，它们的路易斯酸强度比钼边缘的位点酸度小得多。还确定了报道的二硫化钌最具加氢脱硫活性位点的酸强度。一般来说，二硫化钌上该位点的路易斯酸比钼边缘的位点小100%，比二硫化钼硫边缘最有利的位点大20%左右。吡啶分子以η1吸附构型在所考虑位点上的吸附证实了静电势方法所表明的路易斯酸度趋势。
