Effects of zinc on ?-Fe5C2 for carbon dioxide hydrogenation to olefins: Insights from experimental and density function theory calculations

Production of light olefins from CO2, the primary greenhouse gases, is great importance to mitigate adverse effects CO2 emission on environment and supply value-added products non-petroleum resource. However, development robust catalyst with controllable selectivity stability remains a challenge. Herein, we report that Zn-promoted Fe can boost stable selective production CO2. Specifically, exhibits highly activity olefin over 200 h time-on-stream compared unpromoted catalyst, primarily owing preservation active ?-Fe5C2 phase. Structural characterizations spent catalysts suggest Zn substantially regulates content iron carbide surface suppresses re-oxidation bulk during reaction. DFT calculations confirm adsorption carbon atoms graphene-like carbonaceous species are not thermochemically favored catalyst. Carbon deposition by CC coupling reactions two dehydrogenation CH intermediate also inhibited. Furthermore, antioxidation were investigated. hydrogenation adsorbed oxygen H2O desorption H2O, which reduces possibility being oxidized chemisorbed oxygen.