Selective removal of CO by methanation reaction has been performed over wash-coated supported metal catalysts in a microchannel reactor with reformate surrogate. The primary screening over a series of Ru- and nickel-based catalysts showed that methanation activity is dependent on the type of metal, metal loading, and promoter. A NiO/CeO 2/Al 2O 3 catalyst exhibited the highest methanation activity with full CO conversion below the detection limit of 50 ppm at 300°C. The stability of this catalyst formulation was determined and moderate deactivation took place within 100 hr test duration. A recently developed NiO/Cr 2O 3/Al 2O 3-catalyst showed similar performance. The catalyst showed full conversion of CO at excellent selectivity of > 50%, thus, CO 2 conversion and methane formation were only moderate. This is an abstract of a paper presented at the 18th International Congress of Chemical and Process Engineering (Prague, Czech Republic 8/24-28/2008).