In U.S. Patent 7,640,936, Philip Morris USA Inc. (Richmond, VA) reveals how to prepare mixed metal oxide catalysts from nanoscale particles for cigarettes. The mixed nanoscale metal oxide catalysts are capable of reducing the concentration of carbon monoxide in the mainstream smoke of a cigarette during smoking, according to inventors Shahryar Rabiei, Firooz Rasouli, and Mohammad R. Hajaligol. The nanoparticles are incorporated into a smoking article component such as tobacco cut filler, cigarette paper and/or cigarette filter material.
The nanoscale multiphase mixed metal oxide catalyst consists of sintered nanoparticles of at least two metal oxides selected from the group consisting of copper oxide, cerium oxide, titanium oxide and iron oxide
Smoking articles, such as cigarettes or cigars, produce both mainstream smoke during a puff and sidestream smoke during static burning. One constituent of both mainstream smoke and sidestream smoke is carbon monoxide (CO). The reduction of carbon monoxide in smoke is desirable.
Despite the developments to date, there remains an interest in improved and more efficient methods and compositions for reducing the amount of carbon monoxide in the mainstream smoke of a smoking article during smoking.
Despite the developments to date, there remains an interest in improved and more efficient methods and compositions for reducing the amount of carbon monoxide in the mainstream smoke of a smoking article during smoking.
A nanoscale mixed metal oxide catalyst can be incorporated into smoking article components in a number of ways. Mixed metal oxide catalysts in the form of a dry powder can be dusted on cut filler tobacco and/or added to the raw materials used to make cigarette paper. The catalyst can also be combined with cigarette filter material during and/or after manufacture of the cigarette filter material.
The nanoscale mixed metal oxide catalysts can be mixed with water or other suitable liquid to form a paste or dispersion. A paste can be combined with the smoking article components prior to or during the cigarette manufacturing process. A dispersion can be coated such as by spray-coating onto the smoking article component. The smoking article component can then be incorporated into the cigarette making process.
