Nut-like MOF/hydroxylated graphene hybrid materials for adsorptive desulfurization of thiophene

Abstract

Nowadays, sulfur compounds in fuel oils are the main source of environmental pollution and ultra-deep desulfurization of fuel oils has become a top priority. Many porous materials such as activated carbon and metal–organic frameworks (MOFs) have attracted attention in the field of adsorption desulfurization in recent years. A series of novel MOF/hydroxylated graphene hybrid materials were successfully designed and synthesized with different ratios for application in the field of ADS. The hydroxylated graphene (HG) was found dispersed not just on the surface but also inserted in the MOF crystals in what we call a nut-like structure. It was found that the introduction of a small amount (<8%) of HG does not hinder the formation of the Cu-BTC structure. Meanwhile, the adsorption performances of these composites for thiophene from oils were evaluated using batch adsorption tests at room temperature. The synergistic effect between Cu-BTC and HG in the hybrid materials can improve the adsorption capacity for thiophene molecules. The experimental equilibrium curve fitted well with the theoretical Langmuir isotherm model. The maximum sulfur adsorption capacity of 35.6 mg S g⁻¹ for the hybrid materials was calculated using the Langmuir adsorption equation, which increased by 48% compared to parent Cu-BTC. Thus, these hybrid materials have great potential for application in the adsorptive desulfurization process, especially for thiophenic compounds.