Design, fabrication and investigation synergistic effects of MxOy•CuO (M: Pd, Zn, Mn, La) hollow spheres on alcohol oxidation reaction

Background: Selective catalytic oxidation of alcohols to the corresponding aldehydes and ketones is one of the most important functional transformations for producing fine chemicals owing to the versatile role of the carbonylic group as a building block. Methods: In this work, four types of mixed metal oxides were designed and synthesized. Three types of these mixed metal oxides (Pd center dot PdO center dot CuO, La2O3-CuO and ZnO-CuO) had hollow sphere structure, whereas MnO2-CuO had uniform nanoparticles shape. Pd center dot PdO center dot CuO contained two parts, one was the CuO hollow spheres and the other are the Pd center dot PdO scattered nanoparticles which were decorated on the interior and exterior surfaces of CuO hollow spheres. The as-prepared composites were characterized by FESEM, HRTEM, EDS, XRD, and ICP techniques. These new mixed metal oxides were successfully applied to catalysis of the oxidation reaction of alcohol to aldehyde. Significant Findings: The results showed that these nanoparticles on the CuO hollow spheres have a synergistic effect which enhances the efficiencies of the catalysts in the oxidation reaction. This method was highlighted by its broad substrate scope, environmentally friendly reaction conditions (the reaction proceeded in water), the recyclability of the catalyst, low catalyst usage, operational simplicity and high yields. (C) 2021 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

This study designed and synthesized four types of mixed metal oxide catalysts, three of which had hollow sphere structure while one had uniform nanoparticles shape. These new mixed metal oxides exhibited high efficiency, environmentally friendly reaction conditions, recyclability, low catalyst usage, and high yields in the catalytic oxidation reaction of alcohols to aldehydes.