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.

提高镍、钒的去除效率对于石油工艺升级和环境保护具有重要意义。本文通过理论研究揭示了脱金属剂中的S原子和金属卟啉中的金属原子是活性位点。此外，通过几何、马利肯电荷、前沿分子轨道和密度泛函理论（DFT）计算的相互作用能分析，充分探索了Ni/V卟啉和脱金属剂的相互作用机制。结果表明，在1:1化学计量基础上，脱金属剂与金属卟啉之间的相互作用更强，并且脱金属剂更容易与氧钒基卟啉发生反应。此外，还研究了微波电场对金属卟啉与脱金属剂相互作用的影响。结果表明0.005 au平行电场的存在有利于金属卟啉的脱金属过程。