NOVELTY - An article (A1) comprises: a substrate (10) having inlet end (14), outlet end (14'), a length extending between inlet end and outlet end, wall elements and a number of cells (16) defined by wall elements; a first layer deposited on wall elements from inlet end and extending at least partially toward outlet end, and comprising preferential carbon monoxide oxidation catalyst; and a second layer deposited on at least part of first layer from outlet end and having length of 10 - 70% of wall element's length and comprising methanation catalyst consisting ruthenium component and support.    USE - For removing carbon monoxide from a hydrogen gas stream (claimed), for incorporating in the fuel processors that supply hydrogen to a fuel cell for enhanced fuel efficiency.    ADVANTAGE - The article provides improved carbon monoxide removal by treating hydrogen gas streams to achieve very low threshold levels of carbon monoxide e.g. below 10 ppm. The articles are compact and do not require extensive provisions for installation into fuel cell processors.    DETAILED DESCRIPTION - An article (A1) comprises: a substrate (10) having inlet end (14), outlet end (14'), a length extending between inlet end and outlet end, wall elements and a number of cells (16) defined by wall elements; a first layer deposited on wall elements from inlet end and extending at least partially toward outlet end, and comprises preferential carbon monoxide oxidation catalyst; and a second layer deposited on at least part of first layer from outlet end and having length of 10 - 70% of wall element's length and comprises methanation catalyst consisting ruthenium component and support. The carbon monoxide oxidation catalyst is platinum- and/or palladium-based catalyst consisting of 1 - 5 wt.% of platinum or palladium, support and an optional promoter.    An INDEPENDENT CLAIM is also included for process for removing carbon monoxide in a hydrogen stream, involving contacting the hydrogen stream with the article (A1).    DESCRIPTION OF DRAWING(S) - The figure shows perspective view of a honeycomb substrate.    an inlet end (14)    outlet end (14')    outer surface (12)    several parallel cells. (16)