Print Email Facebook Twitter Selectivity control between reverse water-gas shift and fischer-tropsch synthesis in carbon-supported iron-based catalysts for CO2 hydrogenation Title Selectivity control between reverse water-gas shift and fischer-tropsch synthesis in carbon-supported iron-based catalysts for CO2 hydrogenation Author Meng, Weixin (Rijksuniversiteit Groningen) de Jong, B. (Rijksuniversiteit Groningen) van de Bovenkamp, Henk V. (Rijksuniversiteit Groningen) Boer, Gert Jan (Rijksuniversiteit Groningen) Leendert Bezemer, G. (Shell Global Solutions International B.V.) Dugulan, A.I. (TU Delft RST/Fundamental Aspects of Materials and Energy; TU Delft RID/TS/Instrumenten groep) Xie, Jingxiu (Rijksuniversiteit Groningen) Date 2024 Abstract CO2 hydrogenation to chemicals and fuels has the potential to alleviate CO2 emissions and displace fossil resources simultaneously via consecutive RWGS and FTS reactions, also known as CO2-FTS. As Fe-based catalysts are active and selective for both reactions, their bifunctionality requires a delicate balance between the RWGS and FTS. In this work, we investigated the thermodynamic constraints of RWGS and CO2-FTS, the influence of CO2 conversion on selectivity and the influence of Fe nanoparticle size within the range of 4.7 to 10.3 nm. An inert carbon support was selected to rule out metal-support interaction and promoting effects of the support. Catalytic performance was evaluated at 300 °C, 11 bar, H2/CO2/Ar = 3/1/1, 600 to 72000 mL·gcat-1·h-1. At a CO2 conversion level below RWGS equilibrium conversion of 23 %, RWGS was found to be the primary and dominant reaction. No primary Sabatier reaction was observed. At higher CO2 conversion till the CO2-FTS threshold of 42 %, the secondary FTS reaction became dominant. Notably, a non-linear relation between CO2 conversion and CO selectivity was discovered. Comparing two catalysts with identical 5 wt% Fe loading but different average Fe nanoparticle size (6.6 and 8.4 nm), the 8.4 nm Fe catalyst was at least two times more active than the 6.6 nm Fe catalyst. In situ Mössbauer spectroscopy suggested a positive correlation between particle size, carburization and selectivity towards long-chain hydrocarbons. For these potassium-promoted carbon-supported Fe-based catalysts, nanoparticles of at least 8 nm are required for the formation of Fe carbides and improved reactivity. Subject CO hydrogenationFe-based catalystsFTSParticle sizeRWGS To reference this document use: http://resolver.tudelft.nl/uuid:05541a1d-234e-4821-9d97-0f68c1a3c5fc DOI https://doi.org/10.1016/j.cej.2024.151166 ISSN 1385-8947 Source Chemical Engineering Journal, 489 Part of collection Institutional Repository Document type journal article Rights © 2024 Weixin Meng, B. de Jong, Henk V. van de Bovenkamp, Gert Jan Boer, G. Leendert Bezemer, A.I. Dugulan, Jingxiu Xie Files PDF 1-s2.0-S1385894724026536-main.pdf 4.78 MB Close viewer /islandora/object/uuid:05541a1d-234e-4821-9d97-0f68c1a3c5fc/datastream/OBJ/view