Method to stabilize base metal catalysts by overcoating via atomic layer deposition and resulting product
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.
1. 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; and
wherein the protective thin film comprises a material selected from the group consisting of AlO x HfO x , HfSiO x , LaO 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.
2. The method of claim 1 , wherein the metal or metal-containing particle comprises a base metal or a noble metal.
3. The method of claim 1 , wherein the metal or metal-containing particle comprises a base metal.
4. 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).
5. The method of claim 1 , wherein the supported catalyst in whose presence the condensed-phase, heterogeneously catalyzed reaction is conducted is produced by a method comprising:
(a) depositing upon the metal or metal-containing particle supported on 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; wherein the protective thin film comprises a material selected from the group consisting of AlO x HfO x , HfSiO x , LaO 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; 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.
6. The method of claim 5 , wherein step (a) comprises depositing upon the surface a protective thin film of from about 1 nm thick to about 75 nm thick.
7. The method of claim 5 , wherein step (a) comprises depositing upon the surface a protective thin film of from about 1 nm thick to about 50 nm thick.
8. The method of claim 5 , wherein step (a) comprises depositing upon the surface a protective thin film of from about 1 nm thick to about 10 nm thick.
9. The method of claim 5 , wherein the metal or metal-containing particle comprises a base metal or a noble metal.
10. The method of claim 5 , wherein the metal or metal-containing particle comprises a base metal.
11. The method of claim 5 , 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).