Preparation Of Gold Nanoparticles-based Catalysts For Ultra-deep Oxidative Desulfurization In Fuels

Fuel plays an important role in the energy field and it was widely applied in daily life.However,the sulfur oxides?SO_x?would be released in the combustion of sulfides in fuel,which would cause a series of environmental problems such as acid rain and increased PM2.5 content to affect the health of animals and plants.Therefore,the production of clean fuel is significant for protecting the ecological environment.Currently,hydrodesulfurization technology in industrial application needs to be performed under the conditions of high temperature and high pressure and consumption of hydrogen,inducing the high consumption and the sulfur removal of aromatic sulfides is poor.In this paper,oxidative desulfurization technology with high desulfurization efficiency for aromatic sulfides adopted in mild reaction conditions is researched.And the different supported gold-based nanocatalysts are designed to investigate the oxidative desulfurization?ODS?performance at different conditions.The catalytic mechanism was also probed.The research details and experimental results obtained in this paper are as follows:1.The C₃N₄ was used as a sacrificial mediates for engineering strong metal-support interaction?SMSI?between Au NPs and TiO₂.The gold nanoparticles?Au NPs?were uniformly dispersed on the surface of TiO₂ coated by C₃N₄ via impregnation method.The SMSI between TiO₂ and Au NPs was successfully constructed after the removal of C₃N₄.The structure of catalysts was characterized by TEM,XRD,FT-IR,UV-Vis DRS,HRTEM and XPS,which effectively proved the introduction of C₃N₄ and Au NPs supported on the surface of TiO₂.And the formation of SMSI was found to rely on the thin coating layer of TiO₂ around Au NPs and electron transfer effect between TiO₂ and Au NPs.The obtained catalysts were used in the oxidative desulfurization for fuel by using air as oxidant.As a result,the sulfur removal of DBT under the reaction temperature of 120^oC can reach to 99.7%after 6 h.And it had an excellent sulfur removal on various sulfides such as DBT?4,6-DMDBT and 4-MDBT.Moreover,the sulfur removal can maintain 92.2%after recycling 7times.2.In order to reduce the amount of noble metals.The gold-copper alloy nanoparticles?AuCu NPs?were uniformly dispersed on the surface of titanium dioxide?TiO₂?via deposition-precipitation method,and the AuCu-TiO₂ catalyst was prepared by calcination at high temperature at a hydrogen atmosphere.The crystal structure and morphology of the catalyst were analyzed by XRD,UV-vis,HRTEM and XPS characterizations.Among of them,the alloy structure of catalyst was determined and the electron transfer effect was also revealed.The prepared catalyst was used in the ODS process and the effects of different amount of catalyst,sulfur content,reaction temperatures and interferent on the sulfur removal were discussed.Moreover,the ODS mechanism of catalyst was also explored.As a result,the optimal conditions for the reaction were determined as:m?catalyst?=0.01 g,T=120^oC,t=8h,and the removal under the optimal reaction conditions can reach to 95%.3.The nano-sheet CuO and polyhedron Cu₂O supported Au NPs with specific morphology was prepared and the different catalysts were obtained by calcinating at high temperature at air atmosphere.The specific morphology of catalysts was determined by SEM and TEM characterization.Meanwhile,the interaction between metal and support was revealed by XRD and XPS characterization.The obtained catalysts were applied in the ODS process and the effects of catalysts with different morphology,the calcination temperature,sulfur-containing substrate on the sulfur removal were investigated.Simultaneously,the ODS process of catalysts was also explored.As a result,the polyhedron Cu₂O-supported gold nanocatalyst has an excellent sulfur removal.Under the mind reaction conditions of 120^oC,the sulfur removal of Au-Cu₂O-800 for DBT can reach 97.4%.