首页|Understanding kinetically interplaying reverse water-gas shift and Fischer-Tropsch synthesis during CO2 hydrogenation over Fe-based catalysts

Understanding kinetically interplaying reverse water-gas shift and Fischer-Tropsch synthesis during CO2 hydrogenation over Fe-based catalysts

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Direct CO2 hydrogenation into linear alpha-olefins presents a promising route in carbon-neutral chemical manufacture. This work systematically investigated the variable interplay between Reverse Water-Gas Shift (RWGS) and Fischer-Tropsch Synthesis (FTS) during CO2 hydrogenation using model Na-Fe5C2 catalysts, combining dynamic/steady-state CO/CO2 hydrogenation performance, intrinsic kinetics and multiple characterization results. Na-Fe5C2 proves to be surface-enriched with FeOx sites over which RWGS readily proceeds. Meanwhile, CO2 conversion under integral reaction conditions is limited by the subsequent FTS step due to a lack of available FeCx sites. The catalyst performance is steered by the properties and relative quantities of the two different active sites. Na addition promotes the refresh of FeOx sites and beta-elimination of alkyl intermediates over FeCx sites, but at the cost of inhibiting the surface fraction of FeCx sites and thus the single-pass CO2 conversion. These fundamental understandings will enlighten further development of CO2 hydrogenation catalysts with improved hydrocarbon yields.

CO2 hydrogenationIron-based catalystAlkali metalActive sitesIntrinsic kineticsIRON-OXIDE CATALYSTSCARBON-DIOXIDELOWER OLEFINSLIQUID FUELSADSORPTIONPRODUCTSSYNGASSELECTIVITYACTIVATIONMECHANISMS

Xu, Minjie、Cao, Chenxi、Xu, Jing

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East China Univ Sci & Technol

2022

Applied Catalysis

Applied Catalysis

ISSN:0926-860X
年,卷(期):2022.641
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