Heteroatom-doped Hexagonal Boron Nitride Material For Fuel Adsorption Desulfurization: A DFT Study

People’s material and cultural needs are increasing,and travel is becoming more and more regular.Therefore,the amount of fuel used by travel tools is also increasing rapidly.The sulfur components in the fuel produce sulfur oxides when burned,which causes serious harm to the environment and further affects people’s health.Therefore,it is necessary to reduce the sulfur content of fuel.The commonly used desulfurization method in industry-hydrodesulfurization requires harsh conditions.Adsorption desulfurization is a viable alternative booming method,and finding a suitable adsorbent is the core issue.Hexagonal Boron Nitride(h-BN)has a high specific surface area and excellent stability,and it has been used to adsorb metal ions,biomolecules,carbon dioxide,sulfides,etc.However,the unmodified h-BN has an unsatisfactory effect on the removal of larger molecular aromatic sulfides.Therefore,it is considered that doping and modifying can adjust the electronic structure of h-BN to change the adsorption desulfurization performance.In this paper,the representative sulfide dibenzothiophene(DBT)is selected for adsorption.The h-BN material and its adsorption performance for DBT is investigated through DFT,and the interaction between h-BN and DBT is analyzed.1.A model of fluorine-doped h-BN was constructed to explore the existence of different species and their stability,then the interaction between fluorine-doped h-BN and DBT is analyzed after DBT adsorption.In monoatomic fluorine-doped h-BN,F＿e＿B and F＿t＿B are stable forms.The adsorbent containing F＿t＿B species showed better adsorption performance.Among the diatomic doped species,the species with the best adsorption performance is F＿t＿B + F＿t＿B.Quantum chemical analysis shows that both the F···H–C hydrogen bond and the π–π interaction play an important role.In the diatomic adsorption complex,there is also a strong electrostatic F···S–C interaction.Therefore,F doping can enhance the performance of DBT adsorption.2.Halogen doped(X = Cl,Br,I)h-BN was further investigated for DBT adsorption,and compared with F-doped h-BN.The results show that the most stable doping energy is the marginal B–X species(X＿edge＿B).Compared with the adsorption energy of original h-BN,all halogen doped h-BN have stronger adsorption properties.Quantum chemical analysis shows that there is not only π–π interaction between halogen doped h-BN and DBT,but also the additional X···H–C hydrogen bond can further enhance the adsorption of DBT.There is also F···S–C interaction in F-doped h-BN.Therefore,h-BN doping halogen can improve its adsorption desulfurization performance.3.The DBT adsorption interaction of oxygen-doped h-BN was explored.The two species which are most stable and with better adsorption properties are OH＿edge＿B and OH＿top＿B.Compared with the original h-BN,all oxygen-doped h-BN has higher ADS performance,and as the oxygen content increases,the adsorption strength of DBT also increases.Therefore,the oxygen-doped h-BN can enhance the adsorption performance of DBT.Quantum chemical analysis shows that there is a π–π interaction between h-BN＿O and DBT,and the additional O···H–C hydrogen bond further enhances the adsorption of DBT.