Studied On Adsorption Desulfurization Performances Of Porous Carbon Derived From MOFs

One of the main factors that bring polluted air in cities is originated from the combustion and emission of sulfur-containing compounds in fuel oil.Thus,the urgent need for reducing sulfur content in fuel oil to low sulfur or even ultra-clean non-sulfur is a mainstream trend around the world.Adsorptive desulfurization?ADS?,as an economical and effective technique,attracts wide attentions.The key technology of ADS,however,is deemed to the preparation of an excellent adsorbent.In this work,a series of metal embedded porous carbon adsorbents derived from MOFs have been designed to remove sulfur-containing compounds in fuel oil.Firstly,HKUST-1 and ZIF-8,were synthesized by solvothermal method and carbonized at different temperatures to prepare highly porous carbon Cu@C-T and Zn@C-T adsorbents.These carbon adsorbents were analyzed by some characterization technologies including X-ray diffraction?XRD?,scanning electron microscopy?SEM?,energy dispersive X-ray?EDX?transmission electron microscopy?TEM?,N₂adsorption-desorption and X-ray photoelectron spectroscopy?XPS?.The adsorption performances of the adsorbents for dibenzothiophene?DBT?in model oils were investigated by static adsorption desulfurization evalutions.These results demonstrated that an optimal carbonization temperature was 800°C for HKUST-1 and ZIF-8.The obtained Cu@C-800 and Zn@C-800 all exhibited good porous structures and uniformly distributed metal active sites.Simultaneously,the adsorption capacity of Cu@C-800 and Zn@C-800 was higher than those of other adsorbents obtained at different temperature,respectively.Zn@C-800 was provided with high ADS performance?35.5 mg/g?compared to that of Cu@C-800.Secondly,bimetal porous carbon Zn/Co@C-T materials derived from bimetal?Zn,Co?-organic frameworks?bi-MOFs?were fabricated by a carbonization method in this work.The physicochemical properties of the carbon materials were characterized by XRD,SEM,EDX,TEM,N₂ adsorption-desorption and XPS.The results illustrated that Zn/Co@C-800 had good porous structures,uniformly distributed metal active sites,high surface area?531.1 m²/g?and large pore volume?0.449 cm³/g?.In addition,ADS performances of samples for dibenzothiophene?DBT?were systematically investigated by static batch tests.The Zn/Co@C-800 presented higher adsorption capacity?40.6 mg/g?than mono-metal adsorbent Zn@C-800 or Co@C-800,indicating that the remarkable adsorption capacity of it was attributed to the positive bimetalic synergistic effects.Finally,a high-temperature carbonization reduction strategy is adopted for the preparation of Cu,Zn-embedded porous carbon?CuZn@C-n?,by carbonizing the ZIF-8pre-grown on CuO nanosheets?designated as CuO-ZIF-8-n,n represents the molar ratio of Cu and Zn?prepared through a liquid diffusion method.The obtained CuZn@C-0.05 had good porous structures,large pore volume,high surface area,and uniformly distributed bimetallic active sites.XRD?SEM?TEM and XPS results proved that Cu₂O nanoparticales reducted from CuO in CuO-ZIF-8-0.05 were homogeneously dispersed on the carbon matrix,effective forming?-complexation with thiophenic sulfur compounds,which ehanced the ADS performance.The adsorbent exhibited the remarkable adsorption capacity of DBT?60.0 mg/g?compared to those of other carbon adsorbents.