NOVELTY - A catalyst comprises copper oxide, zinc oxide and cerium oxide, where the catalyst is catalytically active for oxidation of carbon monoxide.    USE - In cigarette for oxidation of carbon monoxide; and for oxidizing carbon monoxide from a vehicle exhaust emission, gas used in a laser, gas used in a fuel cell and ambient air undergoing air filtration to carbon dioxide (claimed). The catalyst can be incorporated into a component of a cigarette (e.g. tobacco cut filler, cigarette paper and/or cigarette filter material). The catalyst may be added to cut filler tobacco stock (e.g. loose cut filler) supplied to a cigarette-making machine or incorporated directly on a tobacco rod prior to wrapping a cigarette wrapper around the cigarette rod to form a tobacco column. The catalyst can be incorporated into cigarette wrapping paper by incorporating the catalyst directly into the paper web and/or by incorporating the catalyst in web-filler material used in the production of the wrapping paper.    ADVANTAGE - The copper oxide-zinc oxide catalyst and the copper oxide-zinc oxide-cerium oxide catalyst are capable of room/low temperature oxidation of carbon monoxide. The catalysts reduces the concentration of carbon monoxide from a vehicle exhaust emission, gas used in a laser, gas used in a fuel cell and/or ambient air undergoing air filtration. The catalysts in cigarette convert carbon monoxide to carbon dioxide during smoking of the cigarette.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) forming a copper oxide-zinc oxide catalyst and copper oxide-zinc oxide-cerium oxide catalyst involves co-precipitating a mixture of copper hydroxide and zinc hydroxide or co-precipitating a mixture of copper hydroxide, zinc hydroxide and cerium hydroxide respectively; optionally filtering the mixture; optionally washing the mixture with deionized water; drying the mixture; and calcining the mixture. For forming the copper oxide-zinc oxide catalyst involves aging the mixture before filtering;    (2) the copper oxide-zinc oxide catalyst and copper oxide-zinc oxide-cerium oxide catalyst;    (3) a cigarette comprising a tobacco rod, cigarette paper and an optional filter, where at least one of the tobacco rod, cigarette paper and filter comprise the catalyst (e.g. copper oxide-zinc oxide catalyst and copper oxide-zinc oxide-cerium oxide catalyst); and    (4) oxidizing carbon monoxide to carbon dioxide involving contacting the copper oxide-zinc oxide catalyst or copper oxide-zinc oxide-cerium oxide catalyst with a gas containing carbon monoxide, the gas is selected from a vehicle exhaust emission, gas used in a laser, gas used in a fuel cell and ambient air undergoing air filtration.