Core/shell catalyst particles and method of manufacture

A method of making an automotive catalyst composite, the method comprising:

• obtaining a plurality of particles in an aqueous suspension for a core structure, the particles having a primary particle size distribution d90 of up to about 5 μm and comprising one or more metal oxides;
• obtaining a solution of nanoparticles of one or more metal oxides having a primary particle size distribution d90 in the range of about 5 nm to about 1000 nm (1 μm);
• mixing the aqueous suspension for the core structure and the solution of nanoparticles to form a mixture;
• spray-drying the mixture for form a plurality of core-shell support particles;
• treating the core-shell support particles with one or more platinum group metals (PGMs) to form a catalytic material;
• and
• depositing the catalytic material on a carrier.

A particulate material adapted for use as a coating on a catalyst article, comprising:

• a plurality of core-shell support particles comprising a core and a shell surrounding the core,
• wherein the core comprises a plurality of particles having a primary particle size distribution d90 of up to about 5 μm, wherein the core particles comprise particles of one or more metal oxides;
• and
• wherein the shell comprises nanoparticles of one or more metal oxides, wherein the nanoparticles have a primary particle size distribution d90 in the range of about 5 nm to about 1000 nm (1 μm);
• and
• one or more platinum group metals (PGMs) on the core-shell support, wherein the core-shell support particles are in dry form or in aqueous slurry form.