Hydrothermally stable MOFs for CO2 hydrogenation over iron-based catalyst to light olefins

Abstract

Two types of hydrothermally stable MOFs, ZIF-8 and MIL-53(Al) with different size and morphology, were prepared and used as supports for catalysts for synthesis of hydrocarbons from CO2 hydrogenation. XRD patterns proves that all these two types of MOFs materials could be stable under the reaction conditions (P=3MPa; T=573K) with water as byproduct. MOFs as a novel porous materials show excellent properties on catalysis compared with traditional supports γ-Al2O3 and the type of MOF supports has a significant impact on the activity and selectivity of Fe catalysts for CO2 hydrogenation. Due to the acidity of supports, ZIF-8 supports show different levels of considerable light olefins selectivity, while all MIL-53 supports nearly could not obtain light olefins. The light olefins selectivity of ZIF-8 is also affected by the secondary reaction of hydrogenation during the internal diffusion process. In this article, catalyst with high active and high light olefins selectivity was obtained just by modulating the MOFs supports.