Method of making a smoking composition

Abstract

The present invention relates to smoking articles such as cigarettes, and in particular to catalytic systems containing metallic or carbonaceous particles that reduce the content of certain harmful or carcinogenic substances, including polyaromatic hydrocarbons, tobacco-specific nitrosamines, carbazole, phenol, and catechol, in mainstream cigarette smoke and in side stream cigarette smoke.

1 . A smoking article comprising a tobacco cut filler with catalytic metal oxide particles disposed thereon, wherein the metal oxide particles have an average particle size of less than 500 nm, the smoking article further comprising at least one nitrate or nitrite source selected from the group consisting of alkali metal nitrate, alkaline earth metal nitrate, alkali metal nitrite, alkaline earth metal nitrite, zinc nitrate, zinc nitrite, and mixtures thereof, wherein the concentration of nitrogen in the tobacco cut filler from the nitrate or nitrite source is from about 0.4 to about 1.5 wt. % nitrogen. 
   
   
       2 . The smoking article of  claim 1 , wherein the metal oxide particles have an average particle size of less than 50 nm. 
   
   
       3 . The smoking article of  claim 1 , wherein the metal oxide particles have an average particle size of less than 5 nm. 
   
   
       4 . The smoking article of  claim 1 , wherein the metal oxide comprises a transition metal. 
   
   
       5 . The smoking article of  claim 1 , wherein the metal oxide comprises at least one metal selected from the group consisting of palladium, platinum, rhodium gold, cobalt, and copper. 
   
   
       6 . The smoking article of  claim 1 , wherein the metal oxide is selected from the group consisting of iron oxide, silver oxide, and zinc oxide. 
   
   
       7 . The smoking article of  claim 1 , comprising an agglomeration or cluster of two or more metal oxide particles. 
   
   
       8 . The smoking article of  claim 1 , comprising a support material, wherein metal oxide particles are disposed on the support material. 
   
   
       9 . The smoking article of  claim 8 , wherein the support material comprises silica or alumina. 
   
   
       10 . The smoking article of  claim 1 , wherein the metal oxide particles are crystalline. 
   
   
       11 . The smoking article of  claim 1 , wherein a concentration of catalytic metal oxide particles in the tobacco cut filler is from 0.005% (w/w) to 0.15% (w/w). 
   
   
       12 . The smoking article of  claim 1 , wherein the tobacco cut filler further comprises a reducing agent. 
   
   
       13 . The smoking article of  claim 12 , wherein the reducing agent is a reducing sugar. 
   
   
       14 . The smoking article of  claim 12 , wherein the reducing sugar is sorbitol. 
   
   
       15 . The smoking article of  claim 12 , wherein the reducing agent is a polyhydric alcohol. 
   
   
       16 . The smoking article of  claim 15 , wherein the polyhydric alcohol is selected from the group consisting of glycerol, ethylene glycol, and propylene glycol, and polyglycol. 
   
   
       17 . The smoking article of  claim 1 , wherein the alkaline earth metal is calcium. 
   
   
       18 . The smoking article of  claim 1 , wherein the alkaline earth metal is magnesium. 
   
   
       19 . The smoking article of  claim 1 , wherein the alkaline earth metal nitrate is magnesium nitrate. 
   
   
       20 . The smoking article of  claim 1 , wherein the alkaline earth metal nitrate is Mg(NO 3 ) 2 -6H 2 O.