ZIF-derived Co@carbon nanofibers for enhanced chemical fixation of CO₂

CO₂ cycloaddition with epoxides to produce cyclic carbonates is a promising method for the resourceful use of CO₂, but it remains a great challenge. Herein, one-dimensional Co@carbon nanofibers (Co@CNFs) catalysts were synthesized for the first time by one-step pyrolysis of electrospinning ZIF-67-mixed nanofibers, and their microstructures and catalytic performance for the CO₂ cycloaddition with epichlorohydrin were controlled by adjusting the pyrolysis temperature and ZIF-67 amount. The as-prepared Co@CNFs-700–0.45 catalyst shows the highest catalytic activity, which is 1.9 times higher than Co@CNFs-450–0.45 and 1.3 times higher than Co@CNFs-900–0.45. Higher specific surface area and abundant hierarchical pores, enhanced both surface defects and acidic/alkaline sites, and more Co nanoparticles with small particle size are the key reasons for the superior activity of Co@CNFs-700–0.45. Furthermore, good recoverability of Co@CNFs-700–0.45 is due to its one-dimensional and magnetic properties, which is approved by the excellent stability during six reaction cycles.