20.500.12556/RUL-189581 Multifunctional assessment of rock-salt (Co$_{0.2}$Cu$_{0.2}$Mg$_{0.2}$Ni$_{0.2}$Zn$_{0.2}$)O High-Entropy Oxide CO$_2$ hydrogenation activity and environmental impact In this study, high-entropy oxide (HEO) (Co$_{0.2}$Cu$_{0.2}$Mg$_{0.2}$Ni$_{0.2}$Zn$_{0.2}$)O was synthesized via two different approaches, combustion synthesis (CS) and a solvent-deficient mechanochemical method (SDM), and comparatively investigated in terms of structural properties, catalytic performance in CO$_2$ hydrogenation, and environmental impact through phytotoxicity assessment. X-ray diffraction confirmed the formation of a phase-pure cubic rock-salt structure (Fm-3m) for both synthesis routes. However, the CS-derived material exhibited a smaller crystallite size, a higher lattice microstrain, and more pronounced structural anisotropy compared to the SDM counterpart, while both materials showed relatively low specific surface areas. Catalytic testing was performed for CO$_2$ hydrogenation at 20 bar, H$_2$/CO$_2$ = 3, and 200°C–300°C. Both HEO catalysts showed high selectivity toward methanol. The CS catalyst demonstrated markedly superior performance, achieving up to ∼16 mol% CO$_2$ conversion and significantly higher methanol space-time yield (4.2 mmol gcat$^{−1}$ h$^{−1}$) at 300°C compared to the SDM sample. The enhanced activity is attributed to a higher defect density and lattice distortion induced by the combustion route. Environmental assessment using Lemna minor revealed that metal leaching from the HEOs significantly affected phytotoxicity. The CS-derived material showed higher leaching of Cu, Co, and Ni, highlighting a trade-off between catalytic activity and environmental stability. carbon dioxide utilization high-entropy oxides methanol phytotoxicity izraba ogljikovega dioksida oksidi z visoko entropijo metanol fitotoksičnost true false true Angleški jezik Slovenski jezik Članek v reviji 2026-10-09 12:12:40 2026-10-09 12:12:42 2026-10-10 04:29:38 0000-00-00 00:00:00 2026 0 0 15 str. iss. 19, art. e71097 Vol. 18 14. Oct. 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 620.1:504.5 1867-3880 10.1002/cctc.71097 294376707 RAZ_Skalar_Tina_2026.pdf RAZ_Skalar_Tina_2026.pdf 1 5DAFC0251FA8567D99CB4AC0121DCC2C f5ff38073e298aadf9a90c6ae5c5432ffd83397eda9d0492b11900c9a0defc4b c025c9a9-c3ca-11f1-8bc5-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=250234 https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/cctc.71097 1 d0d72335-c3c9-11f1-8bc5-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=250233 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0