Effect of the metal−support interaction in Ag/CeO2 catalysts on their activity in ethanol oxidation

• Published in: Kinetics and catalysis 2017, Vol.58 (5), p.642-648
• Main Authors: Grabchenko, M. V., Mamontov, G. V., Zaikovskii, V. I., Vodyankina, O. V.
• Format: Article
• Language: English
• Subjects: Acetaldehyde; Carbon dioxide; Catalysis; Catalysts; Catalytic activity; Chemistry; Chemistry and Materials Science; Coprecipitation; Dehydrogenation; Electron microscopy; Ethanol; Impregnation; Oxidation; Particle physics; Physical Chemistry; Selectivity; Silver; Transmission electron microscopy
• ISSN: 0023-1584; 1608-3210
• DOI: 10.1134/S0023158417050056

The interaction of silver with the surface of CeO 2 in the Ag/CeO 2 catalysts prepared by coprecipitation and impregnation techniques was studied by temperature-programmed reduction, X-ray diffraction, and high-resolution transmission electron microscopy. It was shown that coprecipitation technique led to formation of strong silver–support interaction and the epitaxy of silver particles ( d 111 = 2.35 Å) on the surface of CeO 2 ( d 111 = 3.1 Å). This provided incresed catalytic activity in the oxidative dehydrogenation of ethanol at relatively low temperatures (a 15% conversion of ethanol with 100% selectivity for the formation of acetaldehyde was reached at 85°C). Above 130°C, the deep oxidation of ethanol to CO 2 becomes the predominant direction of a catalytic reaction, and the Ag/CеО 2 catalyst obtained by impregnation technique was most active in this region as a consequence of the weaker metal–support interaction.