Creation of Active Sites in MOF-808(Zr) by a Facile Route for Oxidative Desulfurization of Model Diesel Oil

MOF-808(Zr) as an important member of metal-organic frameworks (MOFs) has attracted much attention due to its good stability, large surface area and rich zirconium metal centers. However, Zr sites in the structure of MOF-808(Zr) are inactive in many catalytic reactions due to they are well coordinated with organic ligands like 1,3,5-benzenetricarboxylic acid (BTC) and formate anions. Thus, removing formate anions have been attempted to create more active sites in the structure for many reactions while maintaining the structural stability. In this work, we report that the formate ligands in MOF-808(Zr) can be facilely removed by the treatment in hot ethanol for 4 h. The obtained material as a heterogeneous catalyst exhibited superior catalytic activity in the oxidative desulfurization (ODS) reaction of dibenzothiophene (DBT) compared with reported MOFs catalysts. The conversion of DBT in model diesel oil could reach >99 % within a reaction time of 20 min at 323 K, which is five times as that over parent MOF-808(Zr). As a result, the sulfur content was decreased from 1000 ppm to less than 10 ppm. Such catalytic performance should be mainly attributed to the creation of more active sites in the structure of MOF-808(Zr) after the removal of formate anions.