PT and/or PD egg-shell catalyst and use thereof

A precious metal catalyst, wherein said catalyst comprises nanocrystallites of precious metal on a powder support, wherein the nanocrystallites have an average size of from 1 to less than 5 nm, wherein the catalyst comprises precious metal in an amount of at least 1.0 wt. %, based on the weight of the catalyst, and wherein the precious metal is palladium and/or platinum metal;

• and,
• wherein the palladium metal catalyst has a surface enrichment value of from at least 6.5 to at most 150;
• and,
• wherein the platinum metal catalyst has a surface enrichment value of from at least 1.5 to at most 150, and,
• wherein the surface enrichment value (SEV) is determined from the following formula (I):
• SEV=(XPS wt. %−ICP wt. %)/ICP wt. %;
• (I)
• wherein XPS wt. % is the X-ray photoelectron spectroscopy (XPS) measurement and ICP wt. % is the inductively coupled plasma (ICP) measurement of the precious metal content in weight percent of said catalyst.