Preparation and Performances of ZIF-67-Derived FeCo Bimetallic Catalysts for CO2 Hydrogenation to Light Olefins

Abstract

A novel sodium-promoted Fe-Co/NC catalyst prepared by incipient-wet-impregnation method using ZIF-67 as a support was employed to convert CO2 to light olefins through hydrogenation reaction. Properties of the synthesized catalysts calcinated at various temperatures (from 400 to 700 °C) were investigated by XRD, SEM, TEM and Mӧssbauer spectroscopy. Characterization results showed that the support could be fully converted into carbon support above 500 °C, which could anchor metal particles, thus resulting in a uniform dispersion of active components. Furthermore, the Fe-Co alloy was formed during N2 calcination, and was converted into active components, such as Fe3O4, Fe5C2, and Co2C during the reaction. The reaction result indicated that FeCo/NC-600 catalyst exhibited the highest selectivity of light olefins (C2= − C4=, 27%) and CO2 conversion could reach around 37% when this catalyst pyrolyzed at 600 °C in N2. The highest selectivity for light olefins may be related to the combination of suitable particle size and sufficient active sites of iron carbide.