Influence of the O2/CO ratio and the presence of H2O and CO2 in the feed-stream during the preferential oxidation of CO (PROX) over a CuOx/CeO2-coated microchannel reactor

► The catalytic activity of a microreactor (MR) was evaluated in the CO-PROX reaction. ► The catalytic activity of the powder and the MR was established varying O2/CO ratio. ► The effect of the presence of CO2 and H2O was established. ► MR allows a more efficient heat removal during the CO-PROX reaction improving the selectivity. ► CO2 and H2O inhibit the CO conversion of the MR, principally CO2.