Harvesting Zr-based metal-organic frameworks by continuous-flow synthesis as efficient adsorbents for eliminating nitrogen-containing compounds in liquid fuel

Abstract

This work designed a continuous-flow tubular reactor for rapidly and scalably harvesting the metal-organic framework (MOF) of UiO-66(Zr)-NH2. The experimental conditions, including temperature (110–140 °C), holding time (10–30 min), and CH3COOH/H2N-BDC molar ratio (100–250), were carried out to survey their impacts on the product yield and quality. The highest yield and production rate of ∼72% and ∼1.55 g h−1 were obtained at 130 °C, 20 min, and CH3COOH/H2N-BDC ratio 200. The temperature and modulator content significantly influenced MOFs’ crystal morphology, crystallinity, and porosity. Besides, the adopted method also successfully produced UiO-66 and UiO-67 MOFs with high production rates. The adsorptive denitrogenation (ADN) performances were carried out using liquid fuel models containing quinoline (QU) and 2-methyl pyrrole (MP). In batch mode adsorption, the UiO-66-NH2-130-200 sample showed the highest adsorbing quantities of ∼199 and ∼163 mg g−1 for QU and MP, respectively. Furthermore, the prepared MOFs efficiently removed NCCs from liquid fuel under a continuous fixed-bed column process. These demonstrate that modulator-assisted continuous-flow synthesis can be a potential strategy for the scalable harvest of Zr-MOFs with good qualities and high performance in getting rid of NCCs from liquid fuel.