Sulfur removal enhancement by nano cobalt based metal-organic framework

Sulfur compounds in oil or gas products cause poison the refining catalysts and corrode parts of internal combustion engines as well as production of SOx as the precursor of the acid rain. Therefore, sulfur compound removal is very important and necessary for both industrial and environmental reasons [1]. Metal organic frameworks (MOFs) as a new class of crystalline porous materials have received great attention in the past decade due to their intriguing structures. Some advantages of them are: high surface area, uniform structured nanoscale cavities, controllable particle dimensions and morphology, specific adsorption affinities, and the availability of in-pore functionality and outer-surface modification. Additionally, synthesis of nanoscale MOFs can enhance many properties of them [2].Synthesis of a nano porous cobalt based MOF, [Co6(oba)6(CH3O)4(O)2]n·3DMF has been carried out to introduce a new and highly efficient adsorbent of dibenzothiophene (DBT). This compound has been synthesized by sonochemical method using a nonlinear dicarboxylate ligand. Adsorption capacity of this MOF has been investigated in presence of dibenzothiophene (DBT) as a refractory poly-aromatic sulfur compound. We choose this MOF with oba oxygen donor ligand (H2oba = 4,4ʹ-oxybisbenzoic acid) and one unsaturated coordination number around Co metal as the active site with the maximum adsorption value of DBT at around 825 mg/g [3]. An increase at about 2 times in the maximum adsorption value of DBT was observed in presence of this MOF nanostructure as an effective adsorbent.