Zn Promoted Mg-Al Mixed Oxides-Supported Gold Nanoclusters for Direct Oxidative Esterification of Aldehyde to Ester.
Int J Mol Sci
; 22(16)2021 Aug 12.
Article
em En
| MEDLINE
| ID: mdl-34445372
ABSTRACT
The synthesis of ester compounds is one of the most important chemical processes. In this work, Zn-Mg-Al mixed oxides with different Zn2+/Mg2+ molar ratios were prepared via co-precipitation method and supported gold nanoclusters to study the direct oxidative esterification of aldehyde and alcohol in the presence of molecular oxygen. Various characterization techniques such as N2-physical adsorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and CO2 temperature programmed desorption (TPD) were utilized to analyze the structural and electronic properties. Based on the results, the presence of small amounts of Zn2+ ions (~5 wt.%) provoked a remarkable modification of the binary Mg-Al system, which enhanced the interaction between gold with the support and reduced the particle size of gold. For oxidative esterification reaction, the Au25/Zn0.05MgAl-400 catalyst showed the best performance, with the highest turnover frequency (TOF) of 1933 h-1. The active center was believed to be located at the interface between metallic gold with the support, where basic sites contribute a lot to transformation of the substrate.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Óxidos
/
Aldeídos
/
Hidróxido de Alumínio
/
Ouro
/
Hidróxido de Magnésio
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article