Preparation And Modification Of Metal Organic Framework MOF-101 And Its Performance Of Adsorption Desulfurization

A copper-centred metal-organic framework material MOF-101 with 2-bromine terephthalic acid as ligands was synthesized by solvothermal method and modified by being loaded onto Al₂O₃ and loading Ag⁺.The two kinds of composite materials,MOF-101@Al₂O₃ and Ag⁺/MOF-101,were prepared and applied to the adsorptive desulphurisation in model oils.The MOF-101 and Ag⁺/MOF-101 prepared were characterised by powder X-ray diffraction,x-ray fluorescence,Fourier transform infrared spectroscopy,scanning electron microscopy,transmission electron microscope,thermogravimetric analysis and N₂ adsorption-desorption test.The adsorptive desulphurisation performance of MOF-101@Al₂O₃ was quantified by adsorbing thiophene and dibenzothiophene(DBT)from model oils.The effects of adsorption time,loading amounts of MOF-101,temperature and mass ratio of model oil to adsorbent were investigated,and the effect of Al₂O₃ supports on the adsorption capacity and reusability of the composite was also studied.As a result,the introduction of Al₂O₃ supports stabilized the crystal structure of MOF-101 and improved the stability of the composites.Besides,the loss of adsorbents was reduced during the process of adsorption and desorption.It was inferred that the active component MOF-101 in the composite provided most of the adsorption sites for sulfides.The adsorptive desulphurisation performance of Ag⁺/MOF-101 was quantified by adsorbing thiophene,DBT and toluene from different model oils.Specifically,in order to investigate the selective adsorption performance of Ag⁺/MOF-101,the adsorption capacity for thiophene,DBT and toluene were measured in model oils containing aromatics which strongly competed with thiophene-type-sulfides.And the adsorption for trace thiophene and DBT in model oils was also measured to research the deep desulphurisation performance of the composites.As a result,the loading of Ag⁺and significantly weaken the adsorption competitiveness of toluene and enhanced the deep adsorptive desulfurization capacity for DBT.The sulfur concentration of DBT-octane model oil was reduced from 50 ppm to 10.2 ppm.Possible understandings of were put forward to explain the adsorption performance of Ag⁺/MOF-101.Finally,the adsorption kinetics was discussed for a further study of the adsorption progress.The adsorption data can be well-described by the pseudo-second-order kinetic model and the fitting coefficients were all above 0.99.The maximum adsorption capacities calculated by Langmuir model were in good agreement with the experimental data,and the adsorption process of thiophene and DBT on MOF-101 were spontaneous.