TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The mixture is impregnated onto a porous support. The impregnated support is applied as a washcoat on a flow-through monolith.Preferred Components: The support is particulate; and comprises a flow-through monolith.    TECHNOLOGY FOCUS - METALLURGY - Preferred Components: The platinum is present in an amount of 1 - 3 (preferably 2) wt.%, the copper is present in an amount of 4 - 8 (preferably 8) wt.% and the iron is present on the support in an amount of 0.2 - 1 (preferably 0.1 - 1.5, especially 0.25 - 1) wt.%. EXAMPLE - A monolith comparative catalyst was prepared using a washcoat that contained copper (Cu) and platinum (Pt). Alumina powder was impregnated with an amine-stabilized platinum complex to reach a concentration of Pt of 2 wt./wt.%, and the platinum was fixed by the addition of acetic acid. The alumina was dried, and then impregnated using sufficient solution of copper nitrate to yield a copper concentration of 8 wt./wt.%. The alumina was re-dried and calcined at 500degreesC. The alumina was then ball-milled with water until 90% of the particles were less than 10 microns. The slurry, which contained 30% solids, was applied to a cylindrical cordierite monolith (400 cpsi, 3 inches long and three quarters inch wide). The expected dry gain was 2 g/inch3. The process described above was repeated, except the washcoat powder was impregnated for a third time using a ferric nitrate solution, the catalyst re-dried and calcined at 300degreesC. Samples were made with iron at 0.25 wt./wt.% to obtain test catalyst. Thus the test catalyst comprising (wt./wt.%): Cu (8), iron (Fe) (0.25) and Pt (2) and the comparative catalyst comprising (wt./wt.%): Cu (8) and Pt (2) were prepared. The test catalyst core was mounted in a quartz tube and placed in a reactor. The inlet temperature of the catalyst was controlled using a clamshell furnace. The catalyst was conditioned at 120degreesC for at least 4 hours using a reformate containing (on a dry basis) 50% hydrogen (H2), 15% carbon dioxide (CO2), 0.3% carbon monoxide (CO), 0.48% oxygen (O2) and nitrogen (balance). Steam was injected into the reformate at 25 vol./vol.%. The space velocity was set at 10k/hour. The inlet temperature of the catalyst was then reduced to 90degreesC over a period of 4 hours. The temperature was then returned to 120degreesC, and the flow adjusted so that the space velocity was 20 k/hour. The temperature was again reduced to 90degreesC over 4 hours. The two cycles were repeated except that CO flow was stopped and the temperature decrease was achieved in two hours. This test procedure was also conducted for comparative catalyst. The outlet CO (parts per million (ppm)) for 10 and 20 k/hours for test/comparative catalysts were found to be 0/5 and 0/4 respectively at 90degreesC.