Tetra-Shelled Cr1.3Fe0.7O3 Hollow Sphere as an Efficient Catalyst for the CO2 Fixation Reaction Under Mild and Solvent-Free Conditions

The sequestration of atmospheric CO 2 into value-added products is of great interest from economic and environmental perspectives. The tetra-shelled Cr 1.3 Fe 0.7 O 3 hollow sphere as a heterogeneous catalyst was synthesized by a simple hydrothermal method followed by calcination at 600 °C. The synthesized tetra-shelled hollow spheres were characterized by several effective tools. The catalytic performance was studied for the cycloaddition reaction of CO 2 with epoxides under solvent-free conditions. The reaction time, reaction temperature, CO 2 pressure, and the catalyst amount were systematically studied. Under the best-experimented condition ( 0.02 g of the catalyst, 80 °C, 6 h, and 4 bar CO 2 pressure), the catalyst demonstrated a broad substrate scope and functional group tolerance. Besides, the catalyst showed high recycling efficiency for five consecutive reaction cycles with no significant decline in activity.