Molecular dynamics simulations with the combination of FT-IR and ¹H NMR spectra were carried out to study the mechanism of tuned extractive desulfurization by aqueous tetrabutylphosphonium bromide (TBPB). The intermolecular interaction and microstructure of TBPB with water and the sulfur compound dibenzothiophene (DBT) were investigated. Both the spectra and MD simulation results indicated that TBPB with a small amount of water has strong CH–π interaction between TBP⁺ cation and dibenzothiophene (DBT) and hydrogen bonding between Br⁻ anion and DBT, which are the driving forces for extraction of DBT into aqueous TBPB phase in fuel desulfurization. Further addition of water into aqueous TBPB phase causes the solvation of cation and anion, which weakens the interactions of TBPB with DBT and hence facilitates DBT aggregation and TBPB recovery. The results provide an insight into the mechanism of water tuned extraction and regeneration process in fuel desulfurization.

结合FT-IR和¹ H NMR光谱进行了分子动力学模拟，研究了四丁基溴化phosph（TBPB）水溶液调节萃取脱硫的机理。研究了TBPB与水和硫化合物二苯并噻吩（DBT）的分子间相互作用和微观结构。两个光谱和MD模拟结果表明，与TBPB的少量水具有TBP之间的强CH-π相互作用⁺溴之间阳离子和二苯并噻吩（DBT）和氢键合^-阴离子和DBT，这是在燃料脱硫中将DBT萃取到TBPB水溶液相中的驱动力。将水进一步添加到TBPB水溶液相中会引起阳离子和阴离子的溶剂化，从而削弱TBPB与DBT的相互作用，从而促进DBT聚集和TBPB的回收。结果提供了对水调提取和再生过程中燃料脱硫的机理的见解。