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

Abstract

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.

Bandgap Engineering in Novel Fluorite‐Type Rare Earth High‐Entropy Oxides (RE‐HEOs) with Computational and Experimental Validation for Photocatalytic Water Splitting Applications

“…We explored their photocatalytic behavior toward azo dye degradation and photoelectrochemical water splitting for hydrogen generation. All compounds were synthesized using a modified, ecofriendly and simple aqueous sol-gel citrate route developed previously in the synthesis of high-entropy oxides [47] and double and triple perovskite oxides. [48][49][50][51][52][53] Detailed characterization of the as-synthesized RE-HEOs and performance measurements were executed along with theoretical calculations using density functional theory (DFT) to establish a plausible mechanism for photocatalytic detoxification of MB dye and photoelectrochemical (PEC) water splitting by the high entropy oxides.…”

Designing strategies and enhancing mechanism for multicomponent high-entropy catalysts

“…), 17,123,126 high-temperature gas phase reactions (such as NH 3 decomposition, 127 CO oxidation, 128 CO 2 hydrogenation, 129 methane combustion 130 , etc. ), liquid phase organic reactions, 131,132 and photocatalytic reactions 133 . From Fig.…”

Synthesis of mesoporous SiO2–CeO2 hybrid nanostructures with high catalytic activity for transamidation reaction

“…[6][7][8][9][10][11] CeO 2 was mainly employed as an acid-base catalyst for several organic reactions such as the alkylation of aromatic compounds, dehydration of alcohols, dimerization of aldehydes, alcohols, carboxylic acids, and esters to ketones, reduction of benzoic acid and the cyclization of diols. [12][13][14][15][16] Mainly ceria-based noble metal catalysts were applied for different catalytic applications because of their high reactivity. [17][18][19] From a green chemistry point of view, ceria has been receiving a lot of interest as a promoter, automobile exhauster, and pollution abatement material.…”