Key Words:FISCHER-TROPSCH SYNTHESIS; CARBON-DIOXIDE; LIQUID FUELS; CONVERSION; SYSTEM

Abstract:The catalytic hydrogenation of CO2 to light olefins (C-2-C-4) is among the most practical approaches to CO2 utilization as an essential industrial feedstock. To achieve a highly dispersed active site and enhance the reactivity of the reverse water-gas shift (RWGS) reaction, ABO(3)-type perovskite catalysts Sr1-xKxFeO3 with favorable thermal stability and redox activity are reported in this work. The role of K-substitution in the structure-performance relationship of the catalysts was investigated. It indicated that K-substitution expedited the oxygen-releasing process of the SrFeO3 and facilitated the synchronous formation of active-phase Fe3O4 for the reverse water-gas shift (RWGS) reaction and Fe5C2 for the Fischer-Tropsch synthesis (FTS). At the optimal substitution amount, the conversion of CO2 and the selectivity of light olefins achieved 30.82% and 29.61%, respectively. Moreover, the selectivity of CO was up to 45.57% even when H-2/CO2=4 due to CO2-splitting reactions over the reduced Sr2Fe2O5. In addition, the reversibility of perovskite catalysts ensured the high dispersion of the active-phase Fe3O4 and Fe5C2 in the SrCO3 phase. As the rate-determining step of the CO2 hydrogenation reaction to light olefins over Sr1-xKxFeO3 perovskite catalysts, FTS should be further tailored by partial substitution of the B site. In sum, the perovskite-derived catalyst investigated in this work provided a new idea for the rational design of a catalyst for CO2 hydrogenation to produce light olefins.

Volume:13

Issue:5

Translation or Not:no