Adsorptive Desulfurization of Liquid Hydrocarbons Utilizing Granular Cu/Cr-BDC@γ-Al₂O₃ Bimetal-Organic Frameworks

Abstract

A Cu/Cr-BDC@γ-Al2O3 granular bimetal-organic framework was synthesized for the first time, and its performance in adsorption of thiophene from isooctane was investigated. XRD, BET, FT-IR, SEM, and EDX analysis confirmed the successful synthesis of the adsorbent. The adsorption performances of Cr-BDC, Cu-BDC, and Cu/Cr-BDC were compared, and the bimetallic adsorbent had a better performance due to the synergetic effects of the simultaneous presence of metals. Furthermore, the granular adsorbent had a better performance due to the prevention of the particle’s agglomeration. The highest adsorption percentage and adsorbent capacity were 84% and 55 mg/g, respectively. Experimental data fitted with the pseudo-second-order kinetic model as well as the Langmuir and D–R isotherm models indicated that the adsorption was monolayer and chemisorption was the dominating mechanism. The adsorbents were regenerative up to 5 times. Adsorption was due to the weak bonding of lone pair electrons on sulfur atoms of thiophene and empty orbitals of metals.