Solution-based approach to make porous coatings for sinter-resistant catalysts
AssigneeGM Global Technology Operations LLC
InventorsXingcheng Xiao, Gongshin Qi, Ryan J. Day, Ming Yang
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Abstract
Catalyst systems that are resistant to high-temperature sintering and methods for preparing such catalyst systems that are resistant to sintering at high temperatures are provided. Methods of forming such catalyst systems include contacting a support having a surface including a catalyst particle with a solution comprising a metal salt and having an acidic pH. The metal salt is precipitated onto the surface of the support. Next, the metal salt is calcined to selectively generate a porous coating of metal oxide on the surface of the support distributed around the catalyst particle.
Claims14
A catalyst system comprising:
- a platinum group metal catalyst bound to a metal oxide support, the metal oxide support defined by a plurality of particles having an average particle diameter greater than or equal to about 0.8 micrometers to less than or equal to about 5 micrometers, a surface area of the metal oxide support being greater than or equal to about 50 m2/g to less than or equal to about 150 m2/g, the metal oxide support comprising aluminum oxide (Al2O3);
- and
- a crystalline coating of metal oxide nanoparticles that comprise aluminum oxide (Al2O3) disposed on the metal oxide support around the platinum group metal catalyst, wherein the crystalline coating has a porosity of greater than about 20% to less than about 70% and covers greater than or equal to about 1.5% to less than or equal to about 80% of an exposed surface area of the metal oxide support.
A catalyst system comprising:
- a platinum group metal catalyst selected from the group consisting of:
- palladium, platinum, and combinations thereof bound to a metal oxide support comprising aluminum oxide (Al2O3) and defined by a plurality of particles having an average diameter greater than or equal to about 0.8 micrometers to less than or equal to about 5 micrometers, and a surface area of the metal oxide support being greater than or equal to about 50 m2/g to less than or equal to about 150 m2/g;
- and
- a crystalline coating of metal oxide nanoparticles the comprise aluminum oxide (Al2O3) distributed around the platinum group metal catalyst on the metal oxide, wherein the crystalline coating has a porosity of greater than about 20% to less than about 70% and covers greater than or equal to about 1.5% to less than or equal to about 80% of an exposed surface area of the metal oxide support.
A catalyst system comprising:
- a platinum group metal catalyst selected from the group consisting of:
- palladium, platinum, and combinations thereof bound to a metal oxide support comprising aluminum oxide (Al2O3) and defined by a plurality of particles having, an average diameter greater than or equal to about 0.8 micrometers to less than or equal to about 5 micrometers, and a surface area of the metal oxide support being greater than or equal to about 50 m2/g to less than or equal to about 150 m2/g;
- and
- a crystalline coating of metal oxide nanoparticles that comprise aluminum oxide (Al2O3) disposed on the metal oxide support around the platinum group metal catalyst, wherein the metal oxide nanoparticles have an average maximum diameter of greater than or equal to about 0.5 nm to less than or equal to about 50 nm, and the crystalline coating has a porosity of greater than about 20% to less than about 70% and covers greater than or equal to about 1.5% to less than or equal to about 80% of an exposed surface area of the metal oxide support.
Dependencies are inferred from the claim text.