Optimization of the preparation method of CuO/CeO2 structured catalytic monolith for CO preferential oxidation in H2-rich streams

Copper/ceria washcoated monoliths were prepared by a modified dip coating procedure and operated under CO-PROX conditions. Slurry preparation was suitably modified with respect to more conventional procedure in order to improve the washcoat adhesion onto the cordierite walls. Wet instead of dry milling of the powder ceria used to prepare slurry and colloidal ceria addition to the slurry significantly improved washcoat adhesion, due to partial penetration of the washcoat into the cordierite macropores. Moreover, ceria specific surface area and pore size distribution were affected by both preparation and composition of slurry. Samples prepared by modified slurries showed also improved copper dispersion with a consequent higher selectivity to CO2.