Cerium-doped PCN-777 for the CO2 capture and cocatalysts free chemical fixation via oxazolidinones

Abstract

Carbon Capture and Utilization (CCU) has emerged as a significant player in the context of climate change mitigation strategies. This innovative approach of capturing CO₂ and subsequently converting it into valuable products not only combats climate change but creates new economic opportunities. Oxazolidinones are important five-member heterocyclic compounds in many new antibiotics, intermediates in organic synthesis, pesticides, insecticides, and dyes. In this work, we have doped a nitrogen core enriched, zeotype, mesoporous Zirconium (Zr)-based PCN-777 (PCN= porous coordination network) MOF with Cerium (Ce) (Ce@PCN-777). The high density of Ce-doped Zr Lewis acid sites (13 μmol. g⁻¹) and internal pores adorned with triazine Lewis basic groups enabled Ce@PCN-777 to show selective storage of CO₂ with a high Q_st value of 30.3 kJ.mol⁻¹, CO₂/N₂ selectivity of 33.7, with CO₂ uptake of 2.2 mmole. g⁻¹. The enhanced Lewis acidic property and the basic nitrogen-rich triazine moieties produce a synergistic effect for the environmentally friendly, co-catalyst, and solvent-free cycloaddition of epoxides, aromatic amines, and CO₂ at 1 bar, and moderate temperature for the efficient synthesis of oxazolidinones with a high yield of 80–90 % and regioselectivity. Moreover, the catalysts can be recycled for seven consecutive cycles.