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

Skalar, Tina (avtor), Žgajnar Gotvajn, Andreja (avtor), Legan, Maša (avtor), Kostinjuk, Andrij Olegovič (avtor), Likozar, Blaž (avtor), Tatar, Dalibor (avtor), Djerdj, Igor (avtor), Marinšek, Marjan (avtor)

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.

• Jezik: Angleški jezik
• Ključne besede: carbon dioxide utilization, high-entropy oxides, methanol, phytotoxicity
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FKKT - Fakulteta za kemijo in kemijsko tehnologijo
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2026
• Št. strani: 15 str.
• Številčenje: Vol. 18, iss. 19, art. e71097
• PID: 20.500.12556/RUL-189581
• UDK: 620.1:504.5
• ISSN pri članku: 1867-3880
• DOI: 10.1002/cctc.71097
• COBISS.SI-ID: 294376707
• Datum objave v RUL: 09.10.2026

Gradivo je del revije

• Naslov: ChemCatChem
• Skrajšan naslov: ChemCatChem
• Založnik: Wiley-VCH
• ISSN: 1867-3880
• COBISS.SI-ID: 33675013

Licence

• Licenca: CC BY-NC-ND 4.0, Creative Commons Priznanje avtorstva-Nekomercialno-Brez predelav 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by-nc-nd/4.0/deed.sl
• Opis: Najbolj omejujoča licenca Creative Commons. Uporabniki lahko prenesejo in delijo delo v nekomercialne namene in ga ne smejo uporabiti za nobene druge namene.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: izraba ogljikovega dioksida, oksidi z visoko entropijo, metanol, fitotoksičnost