Study On The Regulation Of The Oxygen Vacancy Of Molybdenum Oxide Cluster And Its Catalytic Aerobic Oxidative Desulfurization Performance

The production of more environmentally friendly refined oil products is critical to the global environmental pollution control,and how to remove the sulfur-containing components in fuel oil is a huge challenge facing modern oil refineries.Molecular oxygen,as a green,cheap and easily available oxidant,as a substitute for hydrogen peroxide and other oxidants,has been widely used in deep oxidative desulfurization technology in recent years.However,the activation of molecular oxygen in a mild environment is still a challenge.In this study,the mesoporous silica MCM-41 was used as the support to prepare a low-valence molybdenum oxygen cluster catalyst by the H₂reduction method,and the unsaturated coordination defects and oxygen vacancies produced by it were used to improve the catalytic performance.Applying it to the oxygen oxidative desulfurization experiment,a41.3%（dibenzothiophene）DBT conversion rate was achieved within 6 h at 80^oC,which did not have ideal catalytic performance.Combined with the analysis of the catalyst characterization results such as SEM,XRD and XPS,it is believed that the catalyst may be due to the low active metal loading and less oxygen vacancies,so it does not exhibit excellent oxidative desulfurization performance.Then this study used ZSM-5 as the support and transition metals Mo and V as the active components to perform aerobic oxidative desulfurization（AODS）reaction on DBT in the simulated oil.The ZSM-5 support has a larger specific surface area and can load more active metals,and there is a certain interaction between the Al in the support and the active component Mo,which can be stably anchored on the support,and then added metal component of V can be synergistic with Mo to achieve a better dispersion effect.The prepared catalyst was applied to the oxidative desulfurization reaction with O₂as the oxidant.At 80^oC,a DBT conversion rate of 97.1%was achieved within 6 hours,and the catalytic performance was improved.Combined with catalyst structure characterization methods such as FT-IR,Raman and XPS,it is believed that the oxygen vacancies in the catalyst greatly promote the process of oxygen oxidative desulfurization,and a possible reaction mechanism is proposed based on the characterization results of related literature and this study.