Реферат: Hydrogen and synthesis gas production through hydrocarbon transformation remains the cornerstone of modern industrial and energy sectors. The growing environmental and social challenges are creating an increasing need for advanced, environmentally friendly technologies that minimize carbon emissions. Ethanol dry reforming has been identified as a promising approach to reduce the carbon footprint of the production of hydrogen and syngas. Ethanol, a renewable, non-toxic and easily transported raw material, offers a high yield of hydrogen and requires less conversion energy than methane. As a result, ethanol reforming has been the subject of considerable research interest over the last three decades. The development of reliable and efficient catalysts for dry reforming of ethanol is essential for the sustainable production of hydrogen and syngas [1]. Two series of Ni containing catalyst based on high entropy perovskites: (LaCr0.2Mn0.2Fe0.2Co0.2Ni0.2O3(LCMFCN), LaTi0.2Mn0.2Fe0.2Co0.2Ni0.2O3) and fluorites: (Ce0.2Zr0.2-Hf0.2Ti0.2La0.2O2(CZHTL), Ce0.2Zr0.2Er0.2Ti0.2La0.2O2(CZETL), Ce0.2Zr0.2Nb0.2Ti0.2La0.2O2(CZNTL) were synthesized via the Pechini and citrate methods. Structure characterization has been done using X-ray diffraction. The high entropy perovskite catalysts have a single-phase with perovskite structure, and high entropy fluorite catalysts have single phase with cubic fluorite structure after calcination at 700 °C. TEM showed uniform elemental distribution for both catalysts before and after addition of Ni. H₂-TPR profiles for the perovskite supports showed three distinct peaks, with low- and high-temperature features attributed to surface and bulk oxygen removal, respectively. A new low-temperature peak appeared post-Ni impregnation, corresponding to NiO reduction. Samples show moderate oxygen mobility required for coke-suppression and catalytic activity. The fluorite catalysts, (CZHTL) exhibited a single reduction peak attributed to the reduction of surface oxygen, while (CZETL) and (CZNTL) have two peaks: one below 580 °C related to surface oxygen reduction and the second one at higher temperatures indicating partial reduction of Ce⁴⁺ to Ce³⁺ with oxygen vacancy formation. All reduction peaks shifted to lower temperatures after Ni addition. Textural analysis revealed Type II isotherms for perovskite-based catalysts and Type IV isotherms for fluorite-based materials, indicating macroporous and mesoporous structures, according to IUPAC classification [2]. The Catalytic performance was evaluated under ethanol dry reforming conditions (2% Et-OH + 2% CO2 in Ar, contact time 10 ms). The main products were H2, CO, CO2, and CH4. The ethanol full conversion was achieved at 700 °C for Ni/LCMFCN. The catalyst stability test was carried out for 20 hours. It showed high catalytic activity and stability without deactivation. After the TGA tests showed mass loss ~ 0.06 wt. %, which correlated with TEM data about no coke formation on the surface of the catalyst. Among the fluorite-based catalysts, Ni/CZETL showed the highest efficiency, After the reaction, TEM analysis revealed only minor carbon deposition, indicating good coking resistance, confirmed by the stability for 20 hours reaching 86% ethanol conversion at 700 °C with the hydrogen yield of 70%.

Библиографическая ссылка: Hanna S.A. , Bulavchenko O.A. , Ishchenko A.V. , Eremeev N.F. , Bespalko Y.N.
High Eentropy Oxide Catalysts with Perovskite and Fluorite Structure for Ethanol Reforming
В сборнике Advanced Multicomponent ("High-Entropy") Materials: Abstracts of the VII International School-Conference "Advanced Multicomponent ("High-Entropy") Materials" dedicated to the 100th anniversary of Yuri Aleksandrovich Skakov. – LLC "Epicenter"., 2025. – C.61. – ISBN 978-5-6055117-3-1.

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20 окт. 2025 г.

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