Abstract
Layered double hydroxides (LDHs) with general formula [(Zn 1− y Cu y ) 1− x Al x (OH) 2](NO 3) x · nH 2O ( x≅0.33, 0.6 ≤ y≤1.0, n≅0.5) have been synthesized and characterized by XRD, chemical analysis, and ESR. According to ESR, copper ions exist both as isolated species and as clusters, their relative contribution depending on the overall Cu content. The tendency to form clusters is observed even at a very low absolute Cu concentration. The materials are active in the low temperature liquid phase oxidation of toluene, o-, m-, and p-xylene with hydrogen peroxide. The catalytic reaction involves both the side chain oxidation and the hydroxylation/oxidation of the aromatic ring. The catalytically active centres are formed by isolated copper species. The clustered copper ions are inactive in the oxidation reaction but accelerate the non-productive decomposition of hydrogen peroxide. The catalytic performance is discussed in terms of competition between the process of H 2O 2 decomposition and its consumption in the oxidation reaction.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.