Sol-Gel Synthesis of Ceria-Zirconia-Based High-Entropy Oxides as High-Promotion Catalysts for the Synthesis of 1,2-Diketones from Aldehyde

• Published in: Molecules (Basel, Switzerland) Vol. 26; no. 20; p. 6115
• Main Authors: Tatar, Dalibor, Kojčinović, Jelena, Marković, Berislav, Széchenyi, Aleksandar, Miletić, Aleksandar, Nagy, Sándor Balázs, Ziegenheim, Szilveszter, Szenti, Imre, Sapi, Andras, Kukovecz, Ákos, Dinjar, Kristijan, Tang, Yushu, Stenzel, David, Varga, Gábor, Djerdj, Igor
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 10.10.2021; MDPI
• Subjects: 1,2-diketone-selective conversion of aldehydes; Acidity; Acids; Aldehydes; Catalysts; Catalytic activity; Cations; ceria; ceria–zirconia-based multimetallic oxides; Crystal lattices; Diketones; Direct conversion; high-entropy oxides (HEOs); Lewis acid-promoted direct synthesis of 1,2-diketone; Liquid phases; Morphology; Oxides; pinacol-type oxidative coupling of aldehydes; Sol-gel processes; Spectrum analysis; Synergistic effect; Zirconia; Zirconium dioxide
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules26206115

Efficient Lewis-acid-catalyzed direct conversion of aldehydes to 1,2-diketones in the liquid phase was enabled by using newly designed and developed ceria–zirconia-based high-entropy oxides (HEOs) as the actual catalysts. The synergistic effect of various cations incorporated in the same oxide structure (framework) was partially responsible for the efficiency of multicationic materials compared to the corresponding single-cation oxide forms. Furthermore, a clear, linear relationship between the Lewis acidity and the catalytic activity of the HEOs was observed. Due to the developed strategy, exclusively diketone-selective, recyclable, versatile heterogeneous catalytic transformation of aldehydes can be realized under mild reaction conditions.