Theoretical investigation on the inert pair effect of Ga on both the Ga-Ni-Mo-S nanocluster and the direct desulfurization of 4,6-dimethyldibenzothiophene

Non-periodic computational model for Ga-Ni-Mo-S nanocluster was established and the inert pair effect of Ga species on both the electron structures of the Ga-Ni-Mo-S nanocluster and the direct desulfurization (DDS) reaction of 4,6-dimethyldibenzothiophene(4,6-DMDBT) were systematically investigated. The stability of the established Ga-Ni-Mo-S nanocluster was enhanced due to the inert pair effect of Ga species. Moreover, the inert pair effect of Ga species makes both the electron and bonding properties of the edge active site of the Ga-Ni-Mo-S nanocluster inclined to be similar with the corner active sites. The adsorption behaviors of the reactant and the intermediates over the edge active sites changed profoundly due to the enhanced electron acceptor characteristics. The inert pair effect of Ga made it possible for the 4,6-DMDBT undergo DDS reaction because the activation energy drastically decreased from about 201.50 kJ·mol−1 over Ni-Mo-S cluster to about 154.56 kJ·mol−1 over Ga-Ni-Mo-S nanocluster at the Mo-edge active site, which would be further effectively compensated by the higher adsorption energy (about −50 kJ·mol−1) of the generated C14H13S over the edge active site than the corner active site of the established Ga-Ni-Mo-S nanocluster.