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.