Co/MoS2催化剂加氢脱硫活性的量子化学研究

Co/MoS2催化剂具有优良的加氢脱硫(HDS)性能。采用ZINDO/1的半经验量子化学计算方法和Mo19S38原子簇模型,考察了催化剂表面不同的n(Co)/n(Mo)对MoS2的LUMO轨道能量的影响,以及对二苯并噻吩(DBT)的吸附热及其吸附中间体的电荷分布、几何构型稳定性和LUMO轨道能量的影响。计算结果表明,随n(Co)/n(Mo)的增加,模型催化剂的HDS催化活性是先增后减,以n(Co)/n(Mo)=2/7时对应的催化剂的HDS活性最高。

Quantum chemistry applied to hydrodesulfurization activity of MoS2 catalyst promoted by cobalt

The hydrodesulfurization(HDS) activity of MoS_2 catalyst can be promoted obviously by cobalt.In this work,the semi-empirical quantum chemistry calculation method of ZINDO/1 and Mo_(19)S_(38) atomic cluster model were employed.The influence of Co to Mo molar ratio of the Mo_(19)S_(38) atomic cluster surface on the LUMO energies of MoS_2 model catalyst was investigated,and the influences on the absorption heat of dibenzothiophene(DBT),charge distribution of DBT absorbed intermediates as well as its stability of geometry structure and LUMO energies were also investigated.The results show that the HDS activity of MoS_2 model catalyst increases firstly and then decreases with the increase of the Co to Mo molar ratio on the surface of Mo_(19)S_(38) atomic cluster,which has the optimistic HDS activity when the Co to Mo molar ratio equals to 2/7.