Copper-Silica Sol-Gel Catalysts: Structural Changes of Cu Species upon Thermal Treatment

Abstract

In this work the encapsulation of copper species in sol-gel silica catalysts thermally treated up to 1100 Celsius degree was studied, XRD, TPR, BET data showed the occurrence of a vitrification/densification process upon treatment at temperatures higher than 900 Celsius degree leading to the partial or complete encapsulation of the the copper species by the silica matrix. As result of this process the copper catalyst particles become unavailable for the reaction with gas phase molecules and are not active for reactions such as carbon monoxide oxidation.