Investigation on the adsorption desulfurization effect of carboxyl and phosphotungstic acid modified UiO-66

• Carboxyl modification and phosphotungstic acid modification of UiO-66 by functional modification method. • The prepared adsorbent materials were characterized by different methods, such as XRD, FT-IR, SEM, EDS and so on to explore its structure. • The desulfurization efficiency of the material under different conditions was studied, it was found that the adsorption capacity was higher. • Kinetic studies and mechanism analysis. UiO-66 loading carboxyl and phosphotungstic acid has a good affinity to thiophene (TH). The synthesized catalyst, changed its original structure, which can increase its reactive site and enhance the interaction with thiophene (TH) in order to improve the adsorption performance. Then the structural changes were analyzed by XRD, FT-IR, SEM, BET, EDS and other characterization methods. Through static experiments of adsorption desulfurization, it is found that when the adsorption time is 240 min, the adsorption temperature is 30 ℃ and the oil-to-agent ratio is 100:1, the adsorption effect: UiO-66-(COOH) 2 (UC2)>UiO-66, the highest adsorption capacity can reach 89.99 mg/g; while PTA@UiO-66 (PAU) can reach adsorption equilibrium at 210 min, it has better desulfurization performance than UiO-66. After being recycled for 5 times, the adsorption effect is only slightly decreased: the adsorption capacity of UC2 was still 78.02% of the initial adsorption capacity, while that of PAU was 76.07% of the initial adsorption capacity. According to the adsorption kinetics, the adsorption process of thiophene on the adsorbent UC2 is more consistent with W-M model, and the adsorption of PAU is more in line with the pseudo-first order kinetic equation. In addition, it also includes the process of intraparticle diffusion and liquid film diffusion.