CO removal for hydrogen purification via Water Gas Shift and COPROX reactions with monolithic catalysts

• Water Gas Shift and CO PROX reactions were studied for CO removal from H2-rich stream for PEMFC applications. • Cu and/or Ni over CeO2 or CePrOx coated honeycomb monoliths were successfully tested. • CFD simulation proved that canalizations are not present in monolith-loaded reactor. • CuNi/CePr15 sample for WGS reaction achieved >50% CO conversion, 100% selectivity in CO2-H2 rich stream. • Temperature, contact time, and O2/CO ratio were optimized for COPROX Cu/CeO2 catalyst. A combination of Water Gas Shift (WGS) and CO preferential oxidation (COPROX) reactions is considered a promising approach for CO removal in an H 2 feed employed for PEM fuel cells. Honeycomb monolithic catalysts were studied for this purpose, firstly coated with Ce or Ce-Pr, then with Cu or Cu-Ni, (mass gained ∼35%). Computational Fluid Dynamics simulation showed that outer channels (close to reactor wall) presented a slightly lower flow in comparison with flow in inner ones. The Pr content in WGS monoliths modulated the activity-selectivity ratio showing an optimal value for 15 at.% in case of Ni-containing samples due to a significant selectivity improvement towards WGS (hindering methanation). A Cu/ceria monolithic sample was tested as COPROX catalyst. The CO conversion presented a maximum value with the increase of the operation temperature. Besides, a larger contact time (achieved by modifying monolith length) also enhanced the undesired H 2 oxidation reaction as same as a larger O 2 /CO ratio. As a consequence, a temperature window around to 130 °C, a contact time close to 0.1 g.s/cm 3 , and a O 2 /CO = 1 M ratio was determined as the most adequate parameters set.