Large-Scale Quantum Chemical Calculation on MoS₂ Catalyst and the Effects of Supports

Large-scale and complicated HDS catalytic systems was simulated using "Colors" code to obtain the detail electronic structures of the MoS₂ catalytic species for the understanding of the effects of the support material on the MoS₂ species. The binding energy of the "small" MoS₂ cluster model obtained by "Colors" code were well reproduced than that obtained by DFT, indicating that "Colors" code had enough ability to represent the electronic states of the MoS₂ catalytic species. The outer atoms were more negatively charged. On the other hand, the inner S atoms and Mo atoms possessed more positively charged features. The difference on the atomic charges might be due to the different coordination number of the individual atoms located at the inner and at the outer side of the "large" MoS₂ cluster model. The significant electron transfer from the MoS₂ species to the γ-Al₂O₃ support was observed. The results demonstrated the efficiency of "Colors" code towards the theoretical study on the complicated catalytic systems such as the HDS catalysts.