In this paper, the CO oxidation on Pd/TiO2 and Pd/SnO2/TiO2 catalysts was studied using a non-conventional tool: AC electrical measurements in operando conditions. The structural and textural properties of the obtained powders have been characterized using BET, XRD, SEM, and CO chemisorption. Their redox properties were tested using the TPR technique. The surface dynamics was studied by electrical conductivity measurements under similar conditions with those encountered in the practical use in catalysis and correlated with their performances in CO oxidation. (C) 2017 Elsevier B.V. All rights reserved.