Reduction of carbon monoxide in smoking articles using transition metal oxide clusters

Abstract

Smoking article components, cigarettes, methods for making cigarettes and methods for smoking cigarettes are provided that use transition metal oxide clusters capable of catalyzing and/or oxidizing the conversion of carbon monoxide to carbon dioxide and/or adsorbing carbon monoxide. Cut filler compositions, cigarette paper and cigarette filter material can comprise transition metal oxide clusters.

1 . A component of a smoking article comprising clusters of transition metal oxides, wherein the component is selected from the group consisting of tobacco cut filler, cigarette paper and cigarette filter material.  
     
     
         2 . The smoking article component of  claim 1 , wherein the transition metal is selected from the group consisting of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper and mixtures thereof.  
     
     
         3 . The smoking article component of  claim 1 , wherein the clusters consist of an oxide of a transition metal selected from the group consisting of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper and mixtures thereof.  
     
     
         4 . The smoking article component of  claim 1 , wherein the clusters comprise Fe 2 O 2  and Fe 2 O 3 .  
     
     
         5 . The smoking article component of  claim 1 , wherein the clusters are capable of catalyzing and/or oxidizing the conversion of carbon monoxide to carbon dioxide and/or adsorbing carbon monoxide.  
     
     
         6 . The smoking article component of  claim 1 , wherein the clusters are capable of catalyzing and/or oxidizing the conversion of carbon monoxide by donating oxygen atoms to the carbon monoxide, wherein the clusters have the general formula M x O y  (y>x).  
     
     
         7 . The smoking article component of  claim 1 , wherein the clusters are capable of catalyzing and/or oxidizing the conversion of carbon monoxide in the presence of an external source of oxygen, wherein the clusters have the general formula M x O y  (y≦x).  
     
     
         8 . The smoking article component of  claim 1 , wherein the clusters are present in an amount effective to reduce the ratio in mainstream smoke of carbon monoxide to total particulate matter by at least about 10%.  
     
     
         9 . The smoking article component of  claim 1 , wherein the clusters have a mean particle size of less than about 2 nm or less than about 1 nm.  
     
     
         10 . The smoking article component of  claim 1 , wherein the clusters comprise fewer than about 2,500 atoms or fewer than about 1,000 atoms.  
     
     
         11 . The smoking article component of  claim 1 , wherein the clusters are charge neutral.  
     
     
         12 . The smoking article component of  claim 1 , wherein the clusters are supported on support particles.  
     
     
         13 . The smoking article component of  claim 12 , wherein the support particles are selected from the group consisting of silica gel beads, activated carbon, molecular sieves, magnesia, alumina, silica, titania, zirconia, iron oxide, cobalt oxide, nickel oxide, copper oxide, yttria optionally doped with zirconium, manganese oxide optionally doped with palladium, ceria and mixtures thereof.  
     
     
         14 . The smoking article component of  claim 12 , wherein the support particles comprise nanoscale particles.  
     
     
         15 . The smoking article component of  claim 12 , wherein the clusters comprise less than about 10 wt. % of the support particles.  
     
     
         16 . The smoking article component of  claim 1 , wherein the clusters comprise less than about 10 wt. % of the component.  
     
     
         17 . A cigarette comprising a tobacco rod, cigarette paper and an optional filter, wherein at least one of the tobacco rod, cigarette paper and optional filter comprise clusters of transition metal oxides.  
     
     
         18 . The cigarette of  claim 17 , wherein the transition metal is selected from the group consisting of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper and mixtures thereof.  
     
     
         19 . The cigarette of  claim 17 , wherein the clusters consist of an oxide of a transition metal selected from the group consisting of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper and mixtures thereof.  
     
     
         20 . The cigarette of  claim 17 , wherein the clusters comprise Fe 2 O 2  and Fe 2 O 3 .  
     
     
         21 . The cigarette of  claim 17 , wherein the clusters are capable of catalyzing and/or oxidizing the conversion of carbon monoxide to carbon dioxide and/or adsorbing carbon monoxide.  
     
     
         22 . The cigarette of  claim 17 , wherein the clusters are capable of catalyzing and/or oxidizing the conversion of carbon monoxide by donating oxygen atoms to the carbon monoxide, wherein the clusters have the general formula M x O y  (y>x).  
     
     
         23 . The cigarette of  claim 17 , wherein the clusters are capable of catalyzing and/or oxidizing the conversion of carbon monoxide in the presence of an external source of oxygen, wherein the clusters have the general formula M x O y  (y≦x).  
     
     
         24 . The cigarette of  claim 17 , wherein the clusters are present in an amount effective to reduce the ratio in mainstream smoke of carbon monoxide to total particulate matter by at least about 10%.  
     
     
         25 . The cigarette of  claim 17 , wherein the clusters have a mean diameter of less than about 2 nm or less than about 1 nm.  
     
     
         26 . The cigarette of  claim 17 , wherein the clusters comprise fewer than about 2,500 atoms or fewer than about 1,000 atoms.  
     
     
         27 . The cigarette of  claim 17 , wherein the clusters are charge neutral.  
     
     
         28 . The cigarette of  claim 17 , wherein the clusters are supported on support particles.  
     
     
         29 . The cigarette of  claim 28 , wherein the support particles are selected from the group consisting of silica gel beads, activated carbon, molecular sieves, magnesia, alumina, silica, titania, zirconia, iron oxide, cobalt oxide, nickel oxide, copper oxide, yttria optionally doped with zirconium, manganese oxide optionally doped with palladium, ceria and mixtures thereof.  
     
     
         30 . The cigarette of  claim 28 , wherein the support particles comprise nanoscale particles.  
     
     
         31 . The cigarette of  claim 28 , wherein the clusters comprise less than about 50 wt. % of the support particles.  
     
     
         32 . The cigarette of  claim 17 , wherein the clusters comprise less than about 10 wt. % of the cigarette.  
     
     
         33 . The cigarette of  claim 17 , wherein the clusters comprise less than about 10 wt. % of the tobacco rod, cigarette paper or filter.  
     
     
         34 . A method for incorporating transition metal oxide clusters in and/or on a component of a cigarette comprising: 
 supporting the component in a chamber having a target;    bombarding the target with energetic ions to form transition metal oxide clusters; and    depositing the transition metal oxide clusters on a surface of the component in order to incorporate the transition metal oxide clusters in and/or on the component, wherein the component is selected from the group consisting of tobacco cut filler, cigarette paper and cigarette filter material.    
     
     
         35 . The method of  claim 34 , comprising forming transition metal oxide clusters comprising a transition metal selected from the group consisting of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper and mixtures thereof.  
     
     
         36 . The method of  claim 34 , wherein the chamber is a vacuum chamber.  
     
     
         37 . The method of  claim 34 , comprising bombarding the target in an inert atmosphere or an oxidizing atmosphere.  
     
     
         38 . The method of  claim 34 , comprising bombarding the target in an atmosphere comprising argon and oxygen.  
     
     
         39 . The method of  claim 34 , comprising bombarding the target in an oxidizing atmosphere comprising CO, CO 2 , NO, O 2 , H 2 O or mixtures thereof.  
     
     
         40 . The method of  claim 34 , comprising bombarding the target at a pressure of greater than about 1×10 −4  Torr.  
     
     
         41 . The method of  claim 34 , comprising bombarding the target at a pressure of about atmospheric pressure.  
     
     
         42 . The method of  claim 34 , further comprising supporting the component on a substrate holder having a temperature during the deposition of from about —196° C. to 100° C.  
     
     
         43 . The method of  claim 34 , comprising supporting the component at a distance of from about 2 to 20 cm from the target.  
     
     
         44 . The method of  claim 34 , comprising bombarding the target with a laser.  
     
     
         45 . The method of  claim 34 , comprising bombarding the target using radio frequency sputtering or magnetron sputtering.  
     
     
         46 . The method of  claim 34 , comprising forming the transition metal oxide clusters in the gas phase.  
     
     
         47 . The method of  claim 34 , comprising incorporating the transition metal oxide clusters in an amount effective to reduce the ratio in mainstream smoke of carbon monoxide to total particulate matter by at least about 10%.  
     
     
         48 . The method of  claim 34 , comprising incorporating less than about 10 wt. % transition metal oxide clusters in and/or on the component.  
     
     
         49 . The method of  claim 34 , comprising incorporating transition metal oxide clusters having a mean particle size of less than about 2 nm or less than about 1 nm.  
     
     
         50 . The method of  claim 34 , comprising bombarding a target comprising at least first and second transition metal elements in order to form transition metal oxide clusters comprising a first metallic element supported on support particles comprising a second metallic element and depositing the supported transition metal oxide clusters directly on a surface of a component.  
     
     
         51 . A method of making a cigarette, comprising: 
 (i) incorporating transition metal oxide clusters in and/or on a component of a cigarette selected from the group consisting of tobacco cut filler, cigarette paper and cigarette filter material;    (ii) providing the tobacco cut filler to a cigarette making machine to form a tobacco column;    (iii) placing the cigarette paper around the tobacco column to form a tobacco rod of a cigarette, and    (iv) optionally tipping the tobacco rod with a cigarette filter comprising the cigarette filter material.    
     
     
         52 . The method of  claim 51 , comprising incorporating the transition metal oxide clusters in and/or on the component via spraying or dusting.  
     
     
         53 . The method of  claim 51 , comprising incorporating the transition metal oxide clusters directly in and/or on the component via physical vapor deposition.  
     
     
         54 . The method of  claim 51 , wherein the transition metal oxide clusters comprise at least on transition metal selected from the group consisting of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper and mixtures thereof.  
     
     
         55 . The method of  claim 51 , comprising forming the transition metal oxide clusters in the gas phase.  
     
     
         56 . The method of  claim 51 , comprising incorporating the transition metal oxide clusters in an amount effective to reduce the ratio in mainstream smoke of carbon monoxide to total particulate matter by at least about 10%.  
     
     
         57 . The method of  claim 51 , comprising incorporating less than about 10 wt. % of the transition metal oxide clusters in and/or on the component.  
     
     
         58 . The method of  claim 51 , wherein the transition metal oxide clusters have a mean particle size of less than about 2 nm or less than about 1 nm.  
     
     
         59 . The method of  claim 51 , comprising bombarding a target comprising at least first and second transition metal elements in order to form the transition metal oxide clusters such that the first transition metal element is supported on support particles comprising the second transition metal element and depositing the supported transition metal oxide clusters directly on a surface of the component.  
     
     
         60 . A method for incorporating transition metal oxide clusters in and/or on a component of a smoking article comprising spraying, dusting and/or mixing the transition metal oxide clusters with the component, wherein the component is selected from the group consisting of tobacco cut filler, cigarette paper and cigarette filter material.  
     
     
         61 . A method of smoking the cigarette of  claim 17 , comprising lighting the cigarette to form smoke and drawing the smoke through the cigarette, wherein during the smoking of the cigarette, the transition metal oxide clusters adsorb carbon dioxide and/or convert carbon monoxide to carbon dioxide.  
     
     
         62 . The method of  claim 61 , wherein during the smoking of the cigarette the oxidation state of the transition metal oxide clusters continuously changes.