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PRINCIPAL PUBLICATION AND AUTHORS
Tandem CO2 valorization and ethane dehydrogenation: elucidating the nature of highly selective iron oxide active sites, M. Tasioula (a), E. de Clermont Gallerande (b), S.A. Theofanidis (a,c), A. Longo (b,d), K.A. Lomachenko (b), C. Sahle (b), A.A. Lemonidou (a,e), ACS Catal. 13, 2176-2189 (2023); https:/doi.org/10.1021/acscatal.2c05338 (a) Department of Chemical Engineering, Aristotle University of Thessaloniki (Greece) (b) ESRF (c) AristEng S.à r.l., Luxembourg City (Luxembourg) (d) Istituto per lo Studio dei Materiali Nanostrutturati (ISMN)-CNR, Palermo (Italy) (e) Chemical Process & Energy Resource Institute, CPERI/CERTH, Thessaloniki (Greece)
REFERENCES
[1] https:/climate.ec.europa.eu/ eu-action/climate-strategies- targets/progress-made-cutting- emissions_en (accessed 2023- 10-04). [2] M. Bender, ChemBioEng. Rev. 1, (2014). [3] S.A. Theofanidis et al., ChemCatChem 14 (2022). [4] S.A. Theofanidis et al., J. Catal 388, 52-65 (2020).
active sites, XAS and XRS were applied. The structural modelling of XRS data gave insights into the possible electronic and thus structural modifications, which could not be elucidated using conventional lab-scale techniques. At the Mg L2,3-edge, a stable, spinel-like arrangement between Mg and Fe atoms was observed for Fe-700(5h). The above-mentioned geometry effect enhanced the catalytic performance during CO2-EDH, with the latter exceeding by far the performance of previously reported Fe- and Ga-based catalysts.
Fig. 83: XRS spectra at (a) Mg L2,3- and (b) O K-edges. Comparison among fresh Fe-600(3h) ( ), fresh Fe-700(5h) ( ), used Fe-700(5h) (650°C, TOS=8h) ( ) and reference MgO ( ). c) FDMNES calculations with the use of screening parameters for the reference MgO,
(i) fresh Fe-600(3h) and (ii) fresh Fe-700(5h). Red lines are the summation of the components (grey dashed lines) based on the screening parameters. d) Spectra calculated by QE-XSpectra. Comparison between fresh Fe-700(5h) O K-edge XRS spectrum and calculated
O K-edge spectrum for the cluster [6]Fe-2[6]Mg-[4]Mg. e) Comparison between theoretical and experimental Mg L2,3-edges spectra. The contribution of theoretical [4]Mg and experimental [6]Mg (via reference MgO) spectra reproduce the experimental data of used Fe-700(5h).
and C2H4 yield at a relatively low temperature of 650oC, compared to the SOTA process for ethylene production.
In conclusion, this work shows that CO2 valorisation and conversion to valuable CO, in tandem with ethylene production, can be achieved through CO2-assisted ethane dehydrogenation. Iron oxide-based Fe-700(5h) was the most selective towards C2H4 production, attaining 90% C2H4 selectivity and more than 25% CO2 conversion at 650oC. To unravel the nature of the selective iron oxide