Cobalt-based metal–organic framework for desulfurization of thiophene as a model fuel

Abstract

Persistent economic growth results in rising energy use, which in turn creates new environmental burdens and health risks for people due to the release of toxic gases from the combustion of fuel with sulfur-containing compounds. A cobalt-based MOF (BITSH-1) was investigated for the adsorptive desulfurization of thiophene in iso-octane as a model fuel. BITSH-1 showed a very high thiophene adsorption capacity of 95.38 mg g⁻¹. Interestingly, BITSH-1 with a high surface area of 349.07 m² g⁻¹ achieves high adsorption efficiency at room temperature with substantially less time consumption without fuel oxidation or additional functionalization of the MOF, making it more feasible for an adsorptive desulfurization process. The recyclability of the MOF material showed good adsorption efficiency of thiophene for up to four cycles. The mechanistic features and possible interactions are discussed by modelling the thiophene molecule in the MOF with the help of SCXRD studies. Additionally, the mechanistic aspects of thiophene adsorption were corroborated using isotherms, kinetics, and thermodynamics, which ascertained that the reaction follows pseudo-order kinetics with spontaneity and feasibility. The overall process was found to be an exothermic reaction. Hence, the proposed adsorbent BITSH-1 could be a promising candidate for exclusive thiophenic separation from oil and could be promoted for the desulfurization of thiophenic model fuel.