Nickel ion-exchanged anionic Cu-MOF with hierarchically porous structure for adsorption desulfurization

The adsorption desulfurization technology presents remarkable advantages and is a promising method because of its affordability, gentle operating conditions. Metal-organic frameworks (MOFs) have garnered significant attention owing to their remarkable features, including large specific surface areas, pore volume and the designable structure. The hierarchical porous CuBTC-DMA was successfully synthesized by adding salicylic acid and using the hydrothermal method. Subsequently, Ni ions were introduced into the structure using ion-exchange method. It was found that the doping of salicylic acid and Ni ions did not significant alter the structure of the material. The new type of π-complexed adsorbent, Ni@HP-CuBTC-DMA, was prepared. The results of adsorption desulfurization experiments showed that Ni@HP-CuBTC-DMA-1.5(0.2 M) had the highest adsorption capacity, with the maximum adsorption amounts of 25.63 mg S/g and 41.06 mg S/g for thiophene and benzothiophene , respectively. In the toluene competition experiment, the adsorption amount of thiophene could still reach 19.25 mg S/g. The results of regeneration experiments demonstrate that Ni@HP-CuBTC-DMA-1.5(0.2 M) still has excellent adsorption capacity after four cycles.