Effects of ultrasonic impregnation combined with calcination in N2 atmosphere on the property of Co3O4/CeO2 composites for catalytic methane combustion

Co3O4/CeO2 composites with high surface areas and ultrafine crystalline sizes for catalytic combustion of methane were firstly prepared by a new sol-gel method which combined ultrasonic impregnation treatment and calcination in N2 atmosphere. The samples were characterized by various means such as nitrogen adsorption/desorption, X-ray diffraction (XRD), H2 temperature-programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Results showed that the modified catalyst had the mesoporous structure, comparatively higher amount of surface oxygen and larger oxygen vacancies than others. As a result of the structure and surface composition merits, a high methane combustion conversion (50%) could be obtained at a low temperature of 262 °C for the modified Co3O4/CeO2 composites catalysts. The experimental results demonstrated that ultrasonic impregnation treatment combined with the N2 thermal treatment prior to calcination in air had a promising application for preparation of Co3O4/CeO2 composites catalysts for low-temperature catalytic combustion of methane.

Graphical abstractUltrasonic impregnation can promote the organic reactions and suppresses the formation of active substance soft agglomerates. The superior Co3O4/CeO2 composites can be obtained due to the synergistic effect in the course of processing.Figure optionsDownload full-size imageDownload as PowerPoint slide