Method of forming a coating

Abstract

The heating step forms a coating comprising the decomposition product on at least a part of the internal surface that borders the internal pathway.

1 . A method of forming a coating within an internal pathway, comprising:
 providing a body having an internal surface which defines an internal pathway within the body, the body having an inlet and an outlet both communicating with the internal pathway for passage of a fluid successively into the inlet then through the internal pathway and then out of the outlet;   introducing a liquid solution into the internal pathway so as to fill at least a portion of the internal pathway with the liquid solution, the liquid solution comprising a solute capable of undergoing thermal decomposition, wherein said at least a portion of the internal pathway forms at least 50% of the length of the internal pathway;   heating the liquid solution while the liquid solution fills said at least a portion of the internal pathway to a sufficient temperature so that the solute undergoes thermal decomposition to form a decomposition product within said at least a portion of the internal pathway;   the heating forming a coating comprising the decomposition product on at least a part of the internal surface wherein said at least a part of the internal surface borders the internal pathway.   
     
     
         2 . The method according to  claim 1 , wherein the internal pathway is a channel which has first and second openings at the inlet and outlet respectively and which is fully enclosed by the internal surface between the first and second openings. 
     
     
         3 - 8 . (canceled) 
     
     
         9 . The method according to  claim 1 , wherein the internal pathway is elongate having a length extending between the inlet and the outlet, wherein said at least a portion of the internal pathway that is filled with the liquid solution is filled with an elongate body of the liquid solution, the elongate body of liquid solution having first and second ends, wherein said heating is performed while one of the inlet and the outlet is closed and the other one of the inlet and the outlet is open, the first end of the elongate body of the liquid solution lying closer than the second end to the open one of the inlet and outlet along the length of the internal pathway and the second end of the elongate body of the liquid solution lying closer than the first end to the closed one of the inlet and outlet along the length of the internal pathway, wherein said heating comprises applying heat progressively to successive regions of the elongate body of the liquid solution starting at the first end of the elongate body of the liquid solution and moving towards the second end of the elongate body of the liquid solution, whereby to reduce or prevent expulsion of liquid solution from the liquid pathway. 
     
     
         10 . The method according to  claim 9 , wherein the body is a tube with the inlet at one end of the tube and the outlet at the other end of the tube, wherein said heat is applied by a heat source, and wherein the tube and the heat source are moved relative to one another to cause said progressive application of heat. 
     
     
         11 . The method according to  claim 10 , wherein the heat source is annular and extends around the circumference of the tube and said heat is applied simultaneously all around the circumference of the tube. 
     
     
         12 - 14 . (canceled) 
     
     
         15 . A method of forming a coating within a porous body, comprising:
 providing a porous body having an internal surface which defines a plurality of interconnected internal spaces within the porous body;   introducing a liquid solution into the internal spaces so as to fill the internal spaces with the liquid solution, the liquid solution comprising a solute capable of undergoing thermal decomposition;   heating the liquid solution while the liquid solution fills the internal spaces to a sufficient temperature so that the solute undergoes thermal decomposition to form a decomposition product within the internal spaces;   the heating forming a coating comprising the decomposition product on at least a part of the internal surface.   
     
     
         16 . The method according to any preceding  claim 1 , wherein the decomposition product is a porous solid. 
     
     
         17 - 20 . (canceled) 
     
     
         21 . The method according to  claim 16 , wherein the coating comprises the porous solid decomposition product and a catalyst supported by the porous solid decomposition product, wherein the catalyst comprises metal particles, the metal particles being entrapped within the porous solid decomposition product. 
     
     
         22 . The method according to  claim 1  wherein the solute comprises a metallic cation, and wherein the decomposition product is a metal oxide. 
     
     
         23 . The method according to  claim 22 , wherein the metallic cation is selected from the group consisting of: titanium, zinc, aluminium, magnesium, calcium, scandium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, gallium, germanium, strontium, yttrium, niobium, molybdenum, ruthenium, rhodium, palladium, silver, cadmium, indium, tin, antimony, tellurium, barium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, mercury, thallium, lead, bismuth, zirconium, and lanthanum or actinium group metals. 
     
     
         24 . (canceled) 
     
     
         25 . The method according to  claim 22 , wherein the solute comprises an anion or a ligand, and wherein the anion or the ligand is selected from the group consisting of: nitrate, acetate, acetyl acetonate, nitrite, chloride, citrate, ammonia, carbonyl, cyclopentadienyl and its derivatives, and anions of organic acids including amino acids. 
     
     
         26 - 29 . (canceled) 
     
     
         30 . The method according to  claim 22 , wherein the liquid solution comprises a further solute comprising a further solute metallic cation, the further solute metallic cation being selected from the group consisting of: platinum, palladium, rhodium, osmium, iridium, ruthenium, copper, silver, cobalt, iron, nickel or gold, and wherein said method comprises converting the further solute to form metal particles. 
     
     
         31 . (canceled) 
     
     
         32 . The method according to  claim 30 , wherein after said conversion the metal particles are entrapped within the decomposition product of the said solute. 
     
     
         33 - 34 . (canceled) 
     
     
         35 . The method according to  claim 1 , wherein the solute comprises a metallic cation, wherein the metallic cation is selected from the group consisting of: platinum, palladium, rhodium, osmium, iridium, ruthenium, silver, rhenium, mercury or gold, and wherein said decomposition product is metal in non-compound form. 
     
     
         36 - 37 . (canceled) 
     
     
         38 . The method according to  claims 16 , wherein the coating consists substantially of said porous solid decomposition product, and wherein the method comprises the further step, performed subsequently to the formation of said coating, of providing metal particles within pores of said porous solid decomposition product. 
     
     
         39 - 41 . (canceled) 
     
     
         42 . The method according to  claim 15 , wherein the decomposition product is a porous solid. 
     
     
         43 . The method according to  claim 42 , wherein the coating comprises the porous solid decomposition product and a catalyst supported by the porous solid decomposition product, wherein the catalyst comprises metal particles, the metal particles being entrapped within the porous solid decomposition product. 
     
     
         44 . The method according to  claim 15 , wherein the solute comprises a metallic cation, and wherein the decomposition product is a metal oxide. 
     
     
         45 . The method according to  claim 44 , wherein the liquid solution comprises a further solute comprising a further solute metallic cation, the further solute metallic cation being selected from the group consisting of: platinum, palladium, rhodium, osmium, iridium, ruthenium, copper, silver, cobalt, iron, nickel or gold, and wherein said method comprises converting the further solute to form metal particles. 
     
     
         46 . The method according to  claim 45 , wherein after said conversion the metal particles are entrapped within the decomposition product of the said solute.