Effect of Substrate Properties on Performance of CuO/CeO2 Based Monoliths towards CO Preferential Oxidation in H2-Rich Streams.

Hydrogen is widely produced by catalytic steam reforming of hydrocarbons with water gas shift reaction. Indeed, H2 for PEM fuel cell must be characterised by a CO content lower than 100 ppm; consequently a further purification step of preferential oxidation of CO (CO-PROX) is required. Moreover, the main applications of PEMFC are related to small scale power generators and packed-bed reactors, generally used for CO-PROX, are not enough compact for small dimension applications. Although monoliths have been widely used in exhaust gas cleaning, their application in the CO-PROX reaction is at the early stage. The CO-PROX reaction is significantly affected not only by the catalyst and its active phase but also by the temperature level reached over the catalyst, influenced by the properties of the support. In this work we aim at investigating the role of these properties on the temperature profiles and then on the CO-PROX performances (CO conversion and selectivity). Copper/ceria has been chosen as active phase, due to its activity and selectivity at low temperature. We prepare and test structured catalysts based on copper/ceria by changing the substrate cell density and thermal conductivity. The results will be compared to the results previously obtained over powder.