Conversion of CO2 to light olefins over iron-based catalysts supported on niobium oxide

Abstract

Four iron-based catalysts supported on niobium oxide (Nb2O5) were prepared by impregnation and characterized by TPR, FRX, DRX, and textural analysis. The catalysts were tested in a fixed bed continuous flow unit to convert a mixture of CO2 and H2 to hydrocarbons at atmospheric pressure. All catalysts were active in the range of 623-723 K. The selectivity to hydrocarbons and light olefins increases with the use of alkali metal promoters (K or Cs). At 673 K, the Fe-Cr-K/Nb2O5 showed 26% selectivity to light olefins, representing 5% yield with 20% CO2 conversion. The niobium oxide-supported catalysts were more active and selective than the same catalyst formulation supported on SiO2.