Ion adsorption of oxide layers to hinder catalyst sintering

Patent metadata

Field	Value
Publication number	US-10562017-B2
Application number	US-201715399151-A
Country	US
Kind code	B2
Filing date	Jan 5, 2017
Priority date	Jan 5, 2017
Publication date	Feb 18, 2020
Grant date	Feb 18, 2020

Abstract

Catalysts that are resistant to high-temperature sintering and methods for preparing such catalysts that are resistant to sintering at high temperatures are provided. The catalyst may be prepared by contacting a solution comprising an ionic species with one or more charged surface regions of a catalyst support. A surface of the catalyst support further includes one or more catalyst particles disposed adjacent to the one or more charged surface regions. The ionic species has a first charge opposite to a second charge of the one or more charged surface regions. Next, the ionic species is associated with the one or more charged surface regions to form a layer on the one or more select surface regions. The layer is calcined to generate a coating comprising metal oxide on the one or more select surface regions, where the coating is formed adjacent to the one or more catalyst particles.

First claim

What is claimed is:

1. A method of preparing a sinter resistant catalyst system, the method comprising:
contacting one or more surface regions of a surface of a catalyst support with one or more precursors to increase a point of zero charge (PZC) of the one or more surface regions so as to form one or more charged surface regions, wherein the surface of the catalyst support comprises one or more catalyst particles adjacent to the one or more charged surface regions and wherein the one or more precursors are selected from the group consisting of: potassium (K), sodium (Na), barium (Ba), strontium (Sr), zinc (Zn), lanthanum (La), cerium (Ce), cobalt (Co), yttrium (Y), and combinations thereof;
contacting a solution comprising an ionic species with the one or more charged surface regions of the catalyst support so as to form a layer on the one or more charged surface regions, wherein the ionic species has a first charge opposite to a second charge of the one or more charged surface regions;
and
calcining the layer to generate a coating comprising metal oxide on the one or more charged surface regions, wherein the coating is formed adjacent to the one or more catalyst particles on the surface of the catalyst support, wherein the calcining the layer comprises heating the layer at greater than or equal to about 300° C. to less than or equal to about 600° C. for a time period of greater than or equal to about 2 hours to less than or equal to about 10 hours.

2. The method according to claim 1 , wherein the first charge of the ionic species is negative and the second charge of the one or more charged surface regions is positive, so that the negatively charged ionic species binds to the positively charged surface regions of the catalyst support; or
the first charge of the ionic species is positive and the second charge of the one or more charged surface regions is negative, so that the positively charged ionic species binds to the negatively charged surface regions of the catalyst support.

3. The method according to claim 1 , wherein a pH of the solution is less than the PZC of the one or more charged regions.

4. The method according to claim 1 , wherein the ionic species comprises an element selected from the group consisting of: aluminum (Al), cerium (Ce), zirconium (Zr), iron (Fe), titanium (Ti), silicon (Si), and combinations thereof.

5. The method according to claim 1 , wherein the metal oxide is selected from the group consisting of: aluminum oxide (Al 2 O 3 ), cerium oxide (CeO 2 ), zirconium oxide (ZrO 2 ), iron oxide (Fe 2 O 3 ), titanium dioxide (TiO 2 ), silicon dioxide (SiO 2 ), and combinations thereof.

6. The method according to claim 1 , wherein the catalyst support comprises a metal oxide selected from the group consisting of: cerium oxide (CeO 2 ), aluminum oxide (Al 2 O 3 ), zirconium oxide (ZrO 2 ), titanium dioxide (TiO 2 ), silicon dioxide (SiO 2 ), magnesium oxide (MgO), zinc oxide (ZnO), barium oxide (BaO), potassium oxide (K 2 O), sodium oxide (Na 2 O), calcium oxide (CaO), lanthanum oxide (La 2 O 3 ), and combinations thereof.

7. The method according to claim 1 , wherein the catalyst particle comprises a metal selected from the group consisting of: platinum (Pt), ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Tr), gold (Au), iron (Fe), nickel (Ni), manganese (Mn), and combinations thereof.

8. The method according to claim 1 , wherein the catalyst support is in a powder form and the contacting further comprises mixing the solution comprising the ionic species with the catalyst support to form a mixture, and after the associating, the method further comprises filtering the mixture to collect a filtrate comprising the catalyst support having the layer; and drying the filtrate prior to the calcining.

9. A method of preparing a sinter resistant catalyst system, the method comprising:
contacting one or more surface regions of a surface of a catalyst support with one or more precursors to increase a point of zero charge (PZC) of the one or more surface regions so as to form one or more positively charged surface regions, wherein the surface of the catalyst support comprises one or more catalyst particles adjacent to the one or more positively charged surface regions and wherein the one or more precursors are selected from the group consisting of: potassium (K), sodium (Na), barium (Ba), strontium (Sr), zinc (Zn), lanthanum (La), cerium (Ce), cobalt (Co), yttrium (Y), and combinations thereof;
contacting a solution comprising an anionic species with the one or more positively charged surface regions of a catalyst support so as to form a layer on the one or more positively charged surface regions,
and
calcining the layer to generate a coating comprising metal oxide on the one or more select surface regions, wherein the coating is formed adjacent to the one or more catalyst particles on the surface of the catalyst support and the metal oxide is selected from the group consisting of: aluminum oxide (Al 2 O 3 ), cerium oxide (CeO 2 ), zirconium oxide (ZrO 2 ), iron oxide (Fe 2 O 3 ), titanium dioxide (TiO 2 ), silicon dioxide (SiO 2 ), and combinations thereof, wherein the calcining the layer comprises heating the layer at greater than or equal to about 300° C. to less than or equal to about 600° C. for a time period of greater than or equal to about 2 hours to less than or equal to about 10 hours.

10. The method according to claim 9 , wherein the anionic species comprises an anion represented by a formula [M(OH) x ] y− , where M is an element selected from the group consisting of: aluminum (Al), cerium (Ce), zirconium (Zr), iron (Fe), titanium (Ti), silicon (Si), barium (Ba), strontium (Sr), zinc (Zn), lanthanum (La), cobalt (Co), yttrium (Y), copper (Cu), nickel (Ni), manganese (Mn), vanadium (V), and combinations thereof, and x ranges from 1 to 6 and y ranges from 1 to 5.

11. The method according to claim 9 , wherein a pH of the solution is less than a point of zero charge (PZC) of the one or more positively charged surface regions.

12. The method according to claim 9 , wherein the anionic species is selected from the group consisting of: aluminum hydroxide anion ([Al(OH) 4 ] − ), cerium hydroxide anion ([Ce(OH) 4 ] − ), zirconium hydroxide ([Zr(OH) 4 ] − ), and combinations thereof.

13. The method of claim 1 , comprising:
contacting the solution comprising a cationic species with one or more negatively charged surface regions of the catalyst support, wherein the surface of the catalyst support further comprises the one or more catalyst particles disposed adjacent to the one or more negatively charged surface regions;
associating the cationic species with the one or more negatively charged surface regions to form the layer on one or more select surface regions of the catalyst support; and
calcining the layer to generate the coating comprising metal oxide on the one or more select surface regions, wherein the coating is formed adjacent to the one or more catalyst particles on the surface of the catalyst support and the metal oxide is selected from the group consisting of: aluminum oxide (Al 2 O 3 ), cerium oxide (CeO 2 ), zirconium oxide (ZrO 2 ), iron oxide (Fe 2 O 3 ), titanium dioxide (TiO 2 ), silicon dioxide (SiO 2 ), and combinations thereof.

14. The method according to claim 13 , wherein a pH of the solution is greater than a point of zero charge (PZC) of the one or more negatively charged surface regions.

15. The method according to claim 13 , wherein the cationic species comprises a cation represented by a formula [M(NH 3 ) m ]n + , where M is an element selected from the group consist

Assignees

• Gm Global Tech Operations Llc

Inventors

• Yang Ming
• Qi Gongshin
• Day Ryan J
• Xiao Xingcheng
• Li Wei

Classifications

• B01J23/42 Primary

  Platinum · CPC title

• B01J37/08

  Heat treatment {(B01J37/0009, B01J37/0018 take precedence)} · CPC title

• B01J23/44

  Palladium · CPC title

• B01J37/0217

  Pretreatment of the substrate before coating · CPC title

• B01J37/0221 Primary

  of particles · CPC title