A method of operating a methanation reactor to reduce carbon monoxide concentration in a reformate stream in a fuel cell reformer. The reactor includes a flowpath with a noble metal catalyst supported by a ceramic support such that the reactor preferentially converts carbon monoxide via methanation over that of carbon dioxide. The reduced level of carbon monoxide present in the reformate stream after passing through the methanation reactor reduces the likelihood of poisoning of the catalyst used on the fuel cell anode.