Copper/ceria washcoated monoliths were prepared by means of a modified dip coating procedure and operated under CO-PROX conditions. The effect of the substrate properties (cell density and wall thermal conductivity) was studied. The significant role of the temperature profile on the performances (CO conversion and selectivity to CO2) was found by testing monoliths with different cell density and wall thermal conductivity. High cell density monoliths with substrate showing the higher thermal conductivity (SiC) appear the best option, providing the best thermal management of the process. (C) 2015 Elsevier B.V. All rights reserved.