Theoretical study of the interactions between demetallization agent and Ni/ V porphyrins and the removal under microwave irradiation

Improving the removal efficiency of nickel and vanadium is of great significance for upgrading petroleum process and environmental protection. In this paper, a theoretical study was performed to reveal that the S atom in the demetallization agent and the metal atom in the metalloporphyrin are the active sites. Furthermore, the interaction mechanisms of Ni/V porphyrin and demetallization agent were fully explored via geometrical, Mulliken charges, frontier molecular orbitals, and interaction energy analysis using the density functional theory (DFT) calculations. The results demonstrate that the interaction between the demetallization agent and metalloporphyrin is stronger on the basis of 1:1 stoichiometry and that the demetallization agent reacted more easily with vanadyl porphyrin. In addition, the influence of microwave electric field on the interaction between metalloporphyrin and demetallization agent was investigated. The results suggest the existence of a parallel electric field of 0.005 a.u. is conducive to the demetallization process of metalloporphyrin.