• 文献标题:   Ce-Containing MgAl-Layered Double Hydroxide-Graphene Oxide Hybrid Materials as Multifunctional Catalysts for Organic Transformations
  • 文献类型:   Article
  • 作  者:   STAMATE AE, PAVEL OD, ZAVOIANU R, BREZESTEAN I, CIORITA A, BIRJEGA R, NEUBAUER K, KOECKRITZ A, MARCU IC
  • 作者关键词:   hybrid material, layered double hydroxide, graphene oxide, knoevenagel condensation, tandem reaction, benzyl alcohol oxidation, onepot cascade reaction
  • 出版物名称:   MATERIALS
  • ISSN:  
  • 通讯作者地址:  
  • 被引频次:   7
  • DOI:   10.3390/ma14237457
  • 出版年:   2021

▎ 摘  要

The combination of layered double hydroxides (LDH) with graphene oxide (GO) enables the formation of nanohybrids with improved properties. This work focuses on the structural and catalytic properties of Ce-containing MgAl LDH-GO composites bearing different concentrations of GO in the range of 5-25 wt.%. The synthesis of the composites was performed by co-precipitating the LDH phase in the presence of GO, while their characterization was performed using XRF, XRD, DRIFT, Raman, SEM, nitrogen adsorption-desorption, and acidity-basicity measurements. The LDH-GO composites, showing redox, basic, and acid catalytic functions, were tested in two different types of organic transformations: (i) Knoevenagel condensation and (ii) one-pot cascade oxidation-Knoevenagel condensation. (i) The cinnamic acid was synthesized by the Knoevenagel condensation of benzaldehyde with diethylmalonate. The composites showed catalytic performances in strong contrast to neat LDH or GO, suggesting a synergistic interaction between the two components. During Knoevenagel condensation, the catalytic activity increased with the GO content in the hybrids up to 15 wt.% and decreased afterwards. (ii) 2-Benzoyl-3-phenylacrylonitrile was synthesized by the aerobic oxidation of benzyl alcohol followed by the Knoevenagel condensation with benzoyl acetonitrile using three different non-polar solvents, i.e., toluene, benzene, and mesitylene. The conversion of benzyl alcohol was higher for the hybrid materials compared to the individual components but decreased with the increase of the graphene oxide concentration.