Preparation of intermetallics by metallo-organic decomposition

Abstract

A metallo-organic decomposition process for the preparation of intermetallic powders and films. A liquid mixture containing a first metal precursor and a second metal is heated to a temperature in a first temperature range so as to convert the first metal precursor to a first metal followed by heating to a temperature in a second temperature range so as to form an intermetallic compound by a solid state reaction between the first and second metals. The intermetallic compound can be used as a catalyst in cut filler and/or the filter of a cigarette.

What is claimed is:  
     
         1 . A method of making an intermetallic compound comprising: 
 forming a liquid mixture containing a first metal precursor and a second metal;    preparing a powder mixture by heating the liquid mixture to a temperature in a first temperature range so as to convert the first metal precursor to a first metal; and    heating the powder mixture to a temperature in a second temperature range so as to form an intermetallic compound by a solid state reaction between the first and second metals.    
     
     
         2 . The method according to  claim 1 , comprising combining the second metal with the first metal precursor wherein the first metal is selected from the group consisting of Mg, Al, Ti, Fe, Co, Ni, Cu, Zn, Mo, Ru, Rh, Pd, Ag, Sn, Ce, W, Re, Os, Ir, Pt and Au.  
     
     
         3 . The method according to  claim 1 , comprising combining the second metal with the first metal precursor wherein the first metal precursor consists essentially of a metallo-organic compound.  
     
     
         4 . The method according to  claim 3 , wherein the metallo-organic compound is selected from the group consisting of ethyl hexanoates, acetyl acetonates, oxalates and citrates.  
     
     
         5 . The method according to  claim 1 , comprising forming a liquid mixture that consists essentially of the first metal precursor, the second metal and a solvent.  
     
     
         6 . The method according to  claim 1 , comprising combining the metal precursor with the second metal wherein the second metal is selected from the group consisting of Mg, Al, Ti, Fe, Co, Ni, Cu, Zn, Mo, Ru, Rh, Pd, Ag, Sn, Ce, W, Re, Os, Ir, Pt and Au.  
     
     
         7 . The method according to  claim 1 , comprising combining the metal precursor with the second metal wherein the second metal is a nanoscale powder.  
     
     
         8 . The method according to  claim 1 , comprising heating the powder mixture to form an intermetallic compound that is a nanoscale powder.  
     
     
         9 . The method according to  claim 1 , comprising heating the powder mixture to form an intermetallic compound that is selected from the group consisting of iron aluminides, titanium aluminides, nickel aluminides, copper aluminides, copper-zinc intermetallics and brass.  
     
     
         10 . The method according to  claim 1 , comprising heating the powder mixture to form an intermetallic compound that is substantially oxygen-free.  
     
     
         11 . The method according to  claim 1 , further comprising applying the liquid mixture to a support.  
     
     
         12 . The method according to  claim 11 , wherein the support is selected from the group consisting of a ceramic, metal, plastic or paper.  
     
     
         13 . The method according to  claim 11 , wherein the support is porous.  
     
     
         14 . The method according to  claim 11 , wherein the liquid mixture is applied to the support by spraying, dipping or spin coating.  
     
     
         15 . The method according to  claim 14 , wherein the steps of applying the liquid mixture to the support and heating are performed simultaneously.  
     
     
         16 . The method according to  claim 11 , wherein the support is selected from the group consisting of silica gel beads, carbon/graphite foam, activated carbon and cut filler.  
     
     
         17 . The method according to  claim 1 , further comprising forming a liquid mixture that comprises a polymer former.  
     
     
         18 . The method according to  claim 1 , wherein the step of preparing the powder mixture comprises heating to a temperature in the range of from about 200 to 350° C.  
     
     
         19 . The method according to  claim 1 , wherein the step of heating to the second temperature range comprises heating to a temperature in the range of from about 400 to 750° C.  
     
     
         20 . The method according to  claim 1 , wherein the steps of heating comprise infrared heating or furnace heating.  
     
     
         21 . The method according to  claim 1 , wherein the step of preparing a powder mixture comprises heating in an oxidizing atmosphere and the step of heating to a second temperature range comprises heating in a non-oxidizing atmosphere.  
     
     
         22 . The method according to  claim 1 , wherein the steps of preparing and heating comprise heating in a non-oxidizing atmosphere.  
     
     
         23 . The method according to  claim 1 , wherein the steps of preparing and heating comprise heating in a reducing atmosphere.  
     
     
         24 . The method according to  claim 1 , wherein the steps of preparing and heating comprise heating at about atmospheric pressure.  
     
     
         25 . A method of making a cigarette comprising incorporating the intermetallic powder formed according to  claim 8  in cut filler and/or a filter of the cigarette.  
     
     
         26 . A method of making an intermetallic compound comprising: 
 forming a mixture containing a first metal precursor and a second metal; and    heating the mixture to convert the first metal precursor to a first metal and forming an intermetallic compound by a solid state reaction between the first metal and the second metal.