Preparation and Performances of ZIF-67-Derived FeCo Bimetallic Catalysts for CO 2 Hydrogenation to Light Olefins

摘要

A novel sodium-promoted Fe-Co/NC catalyst prepared by incipient-wet-impregnation method using ZIF-67 as a support was employed to convert CO 2 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 M?ssbauer 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 N 2 calcination, and was converted into active components, such as Fe 3 O 4 , Fe 5 C 2 , and Co 2 C during the reaction. The reaction result indicated that FeCo/NC-600 catalyst exhibited the highest selectivity of light olefins (C 2 = ? C 4 =, 27%) and CO 2 conversion could reach around 37% when this catalyst pyrolyzed at 600 °C in N 2 . The highest selectivity for light olefins may be related to the combination of suitable particle size and sufficient active sites of iron carbide.