Effects of Iron Carbide Crystal Phases and Dopants on the Conversions of Co2 into Ethylene

Abstract

The density functional theory method was used to investigate the conversions of CO2 to ethylene formation on two common iron carbide surfaces: Fe3C(010) and Fe5C2(111). Based on the structure relaxation of reaction intermediates and the elementary reaction transition states. We deduced the most competitive reaction pathways for ethylene production. The main CO2-to-ethylene routes are discussed along with the competition of side products, CO and CH4. Our analyses showed that CO2 conversion is surface structure sensitive, whereas CH4 and C2+ hydrocarbon formations depend on the reactivity of native C atoms in the carbides. To modify the intrinsic catalyst performance, mixing dopants in Fe catalysts is an effective strategy. Herein, we show that doping Zn and Zr can modify local electronic structures and enhance CO2 adsorptions on the catalyst surface.

Keywords: CO2 hydrogenation, light olefin, iron carbide, dopants, reaction mechanism