Synergistic effects of promoters in Fe/YZrOx catalysts for CO2 hydrogenation to higher hydrocarbons

The search for suitable support materials and optimal promoters is an attractive approach to control the product selectivity in Fe-catalyzed CO2 hydrogenation to C2+-hydrocarbons (CO2-modified Fischer–Tropsch synthesis (CO2-FTS)). This study systematically investigates the effects of metal oxide dop...

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Bibliographic Details
Main Authors: Laura Krausser, Elizaveta A. Fedorova, Carsten R. Kreyenschulte, Christoph Kubis, Angelika Brückner, Qingxin Yang, Evgenii V. Kondratenko
Format: Article
Language:English
Published: Tsinghua University Press 2025-06-01
Series:Carbon Future
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Online Access:https://www.sciopen.com/article/10.26599/CF.2025.9200045
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Summary:The search for suitable support materials and optimal promoters is an attractive approach to control the product selectivity in Fe-catalyzed CO2 hydrogenation to C2+-hydrocarbons (CO2-modified Fischer–Tropsch synthesis (CO2-FTS)). This study systematically investigates the effects of metal oxide dopants for ZrO2 as well as a K promoter with or without a transition metal co-promoter for supported FeOx species in Fe/ZrO2-based catalysts on their performance in CO2-FTS. By combining K with a Mn promoter (Mn/K ratio = 0.4) on a Fe/YZrOx catalyst, CH4 selectivity was hindered without decreasing C2-C4 olefin selectivity at 300 °C and 15 bar. The low CH4 selectivity is worth mentioning in comparison with state-of-the-art Fe-based catalysts. The reaction-induced catalyst restructuring was analyzed, revealing a positive influence of the transition metal promoters on the in-situ formation of catalytically active Fe carbides. Temperature-programmed experiments provided insight into the catalyst ability to interact with CO2 and H2, and thus into the nature of surface iron carbides formed in-situ. Furthermore, the influence of K and Mn on the formation of surface intermediates under realistic conditions was studied using operando diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), complementing our understanding of the role of the promoters in improving the formation of the desired products.
ISSN:2960-0561
2960-0421