Method to stabilize base metal catalysts by overcoating via atomic layer deposition and resulting product

Abstract

A method for stabilizing a metal or metal-containing particle supported on a surface is described, along with the resulting composition of matter. The method includes the steps of depositing upon the surface a protective thin film of a material of sufficient thickness to overcoat the metal or metal-containing particle and the surface, thereby yielding an armored surface; and then calcining the armored surface for a time and at a temperature sufficient to form channels in the protective thin film, wherein the channels so formed expose a portion of the metal- or metal-containing particle to the surrounding environment. Also described is a method of performing a heterogeneous catalytic reaction using the stabilized, supported catalyst.

What is claimed is: 
     
         1 . A method for stabilizing a metal or metal-containing particle supported on a surface, the method comprising:
 (a) depositing upon the surface a protective thin film of a material of sufficient thickness to overcoat the metal or metal-containing particle and the surface, thereby yielding an armored surface; and then   (b) calcining the armored surface for a time and at a temperature sufficient to form channels in the protective thin film, wherein the channels so formed expose a portion of the metal- or metal-containing particle to the surrounding environment.   
     
     
         2 . The method of  claim 1 , wherein step (a) comprises depositing the protective thin film using atomic layer deposition (ALD). 
     
     
         3 . The method of  claim 1 , wherein step (a) comprises depositing by ALD a material selected form the group consisting of oxides, nitrides, carbides, and metals. 
     
     
         4 . The method of  claim 1 , wherein step (a) comprises depositing by ALD a material selected from the group consisting of AlO x  HfO x , HfSiO x , LaO x , SiO x , STO, TaO x , TiO x , ZnO x , ZrO x , WO x , CeO x , MgO x , AlN x , HfN x , SiN x , TaN x , TiN x , AlC x , ZrC x , TiC x , WC x , CeC x , and MgC x , wherein subscript “x” is a real, rational number greater than zero. 
     
     
         5 . The method of  claim 1 , wherein step (a) comprises depositing the protective thin film via about 20 to about 200 cycles of ALD. 
     
     
         6 . The method of  claim 5 , wherein step (a) comprises depositing the protective thin film via about 25 to about 100 cycles of ALD. 
     
     
         7 . The method of  claim 5 , wherein step (a) comprises depositing the protective thin film via about 25 to about 75 cycles of ALD. 
     
     
         8 . The method of  claim 1 , wherein the metal or metal-containing particle comprises a base metal or a noble metal. 
     
     
         9 . The method of  claim 1 , wherein the metal or metal-containing particle comprises a base metal. 
     
     
         10 . The method of  claim 1 , wherein the metal or metal-containing particle comprises a metal selected from the group consisting of iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), and lead (Pb). 
     
     
         11 . The method of  claim 1 , wherein step (b) comprises calcining the armored surface for about 30 minutes to about 24 hours, at a temperature of about 400° C. to about 1500° C. 
     
     
         12 . The method of  claim 1 , wherein step (b) comprises calcining the armored surface for about 1 hour to about 12 hours, at a temperature of about 400° C. to about 1000° C. 
     
     
         13 . The method of  claim 1 , wherein step (a) comprises depositing upon the surface a protective thin film of from about 1 nm thick to about 100 nm thick. 
     
     
         14 . The method of  claim 13 , wherein step (a) comprises depositing upon the surface a protective thin film of from about 1 nm thick to about 75 nm thick. 
     
     
         15 . The method of  claim 13 , wherein step (a) comprises depositing upon the surface a protective thin film of from about 1 nm thick to about 50 nm thick. 
     
     
         16 . The method of  claim 13 , wherein step (a) comprises depositing upon the surface a protective thin film of from about 1 nm thick to about 10 nm thick. 
     
     
         17 . The method of any one of  claims 8  to  16 , wherein step (a) comprises depositing the protective thin film via atomic layer deposition or chemical vapor deposition. 
     
     
         18 . A method for stabilizing a metal or metal-containing particle supported on a surface, the method comprising:
 (a) depositing upon the surface via atomic layer deposition or chemical vapor deposition a protective thin film of a material of sufficient thickness to overcoat the metal or metal-containing particle and the surface, thereby yielding an armored surface, wherein the protective thin film has a thickness of from about 1 nm thick to about 100 nm thick; and then   (b) calcining the armored surface for a time and at a temperature sufficient to form channels in the protective thin film, wherein the channels so formed expose a portion of the metal- or metal-containing particle to the surrounding environment.   
     
     
         19 . The method of  claim 18 , wherein step (a) comprises depositing upon the surface a protective thin film of from about 1 nm thick to about 75 nm thick. 
     
     
         20 . The method of  claim 18 , wherein step (a) comprises depositing upon the surface a protective thin film of from about 1 nm thick to about 50 nm thick. 
     
     
         21 . The method of  claim 18 , wherein step (a) comprises depositing upon the surface a protective thin film of from about 1 nm thick to about 10 nm thick. 
     
     
         22 . A composition of matter produced by:
 (a) affixing a metal or metal-containing particle on a surface;   (b) depositing upon the surface a protective thin film of a material of sufficient thickness to overcoat the metal or metal-containing particle and the surface, thereby yielding an armored surface; and then   (c) calcining the armored surface for a time and at a temperature sufficient to form channels in the protective thin film, wherein the channels so formed expose a portion of the metal- or metal-containing particle to the surrounding environment.   
     
     
         23 . The composition of matter of  claim 22 , wherein step (b) comprises depositing the protective thin film via atomic layer deposition or chemical vapor deposition. 
     
     
         24 . A composition of matter comprising:
 a metal or metal-containing particle supported on a surface; and   a protective thin film deposited on top of the metal or metal-containing particle supported on the surface, wherein the protective thin film is of sufficient thickness to overcoat the metal or metal-containing particle and the surface, thereby yielding an armored surface;   wherein the protective surface defines channels that expose a portion of the metal- or metal-containing particle to the surrounding environment.   
     
     
         25 . The composition of  claim 24 , wherein the protective thin film comprises a material selected form the group consisting of oxides, nitrides, carbides, and metals. 
     
     
         26 . The composition of  claim 24 , wherein the protective thin film comprises a material selected from the group consisting of AlO x  HfO x , HfSiO x , LaO x , SiO x , STO, TaO x , TiO x , ZnO x , ZrO x , WO x , CeO x , MgO x , AlN x , HfN x , SiN x , TaN x , TiN x , AlC x , ZrC x , TiC x , WC x , CeC x , and MgC x , wherein subscript “x” is a real, rational number greater than zero. 
     
     
         27 . The composition of  claim 24 , wherein the metal or metal-containing particle comprises a base metal or a noble metal. 
     
     
         28 . The composition of  claim 24 , wherein the metal or metal-containing particle comprises a base metal. 
     
     
         29 . The composition of  claim 24 , wherein the metal or metal-containing particle comprises a metal selected from the group consisting of iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), and lead (Pb). 
     
     
         30 . The composition of  claim 24 , wherein the protective thin film is from about 1 nm thick to about 100 nm thick. 
     
     
         31 . The composition of  claim 24 , wherein the protective thin film is from about 1 nm thick to about 75 nm thick. 
     
     
         32 . The composition of  claim 24 , wherein the protective thin film is from about 1 nm thick to about 50 nm thick. 
     
     
         33 . The composition of  claim 24 , wherein the protective thin film is from about 1 nm thick to about 10 nm thick. 
     
     
         34 . A method of performing a heterogeneous catalytic reaction, the method comprising:
 conducting a condensed-phase, heterogeneously catalyzed reaction in the presence of a supported catalyst, wherein the supported catalyst comprises   a metal or metal-containing particle supported on a surface; and   a protective thin film of a material of sufficient thickness to overcoat the metal or metal-containing particle and the surface, thereby yielding an armored surface, wherein the protective surface defines channels that expose a portion of the metal- or metal-containing particle to the surrounding environment.