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 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.