CO oxidation on ceria studied by electrochemical impedance spectroscopy

Abstract

Electrochemical impedance spectroscopy technique has been widely used to analyze the electrical properties of a large number of materials. In this study, the electrical properties of CeO2 pellets under CO oxidation conditions have been analyzed by electrochemical impedance spectroscopy. CeO2 pellets have been prepared by a conventional precipitation method and sintered at low temperature to satisfy a compromise between large surface area and a high relative density of the pellet. The electrical properties of CeO2 have been investigated under different atmosphere conditions such as N2, O2, CO, CO2, or selected combinations. The electrical sensitivity of CeO2 to the surrounding atmosphere allows to follow the catalytic reaction as a function of the CO : O2 ratio and temperature. The appropriate analysis of the electrical response by electro-chemical impedance spectroscopy could open a new insight to monitor the catalytic response and behavior of any catalyst.