TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The catalyst comprises a metallic component from copper (preferably), silver, gold, palladium, and platinum and/or metal oxides selected oxides of transition metals from Group 3-8 of the Periodic Table and the lanthanides. The metal oxides are oxides of yttrium, titanium, vanadium, niobium, chromium, iron, cerium, and/or lanthanides. The catalyst is in the form of a thin layer supported on a geometrical body placed in at least part of a passageway or on at least part of inner wall of the passageway through which the synthesis gas is transported. It is in the form of pellets, extrudates, tablets, monoliths, and geometrical bodies.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The synthesis gas is an effluent stream from catalytic steam reforming of hydrocarbons, autothermal steam reforming of hydrocarbons, secondary steam reforming of hydrocarbons and gasification of hydrocarbons, gasification of coal or fuel-processing for the production of energy. EXAMPLE - A catalyst composition comprising 2.5 % manganese, 68.8 % zirconium, and less than 0.01 alkali was prepared. In a reactor, 100 g catalyst was arranged in a fixed bed manner. Dry gas and steam were mixed at 200 degrees C and 25 barg. The dimensions of the reactor allowed for the gas to be heated before reaching the catalyst. The temperature of the reactor was raised at 4 degrees C/min starting from approximately 200 degrees C until a temperature hold of 500 degrees C was reached. The contents of carbon monoxide (CO) in the dry exit gas were used for obtaining the CO-conversion. The dry feed gas was introduced at 10 Nl/h with the composition 74.4 % hydrogen, 12.6 % CO, 10 % carbon dioxide, 3 % argon, while water was feed at 4.25 g/h. The catalyst was left one stream of at the hold temperature for 12-24 hours. The reactor was cooled to 200-300 degrees C and heated to hold temperature. The CO-conversion was 6 % at 400 degrees C with a maximum conversion of 79 %. At 425 degrees C, 450 degrees C, and 475 degrees C, the conversion was 11 (79 ) %, 20 (69) %, and 30 (63) %, respectively.