TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The compositionally modulated nanoparticle comprises an atomic composition comprising platinum (55%), iron (17%) and the remainder gold. The compositionally modulated nanoparticle further comprises: a core portion comprising the shape controlled seed material and an interfacial region disposed between the core portion and the shell portion, where the interfacial region comprises an alloy of the mixture and the shape controlled seed material; a surface portion covering the nanoparticle, where the surface portion comprises platinum; and an alloying metal portion selected to enhance catalytic activity of catalytic material, where the alloying metal is iron, cobalt or nickel. Preferred Components: The catalytically active material comprises platinum, and the modifier material comprises a transition metal. The first particle shape is icosahedral. The shape controlled seed material modifies the catalytic durability of the compositionally modulated nanoparticle relative to the catalytically active material. The interfacial portion: comprises an alloy of gold; and further comprises a bimetallic shell material including platinum and a second metal that is iron. The bimetallic shell material forms on epitaxial coating over the core portion, where a surface layer the bimetallic shell material comprises platinum. The core portion comprises a shape to suppress dissolution of the catalytically active material. EXAMPLE - Solution of tetralin (10 ml), oleylamine (10 ml) and chloroauric acid trihydrate (0.1 g) was magnetically stirred under nitrogen flow in air at 15 degrees C. Tert-butylamine-borane complex (0.5 mmol) was dissolved in tetralin (1 ml) and oleylamine (1 ml) and injected into the precursor solution. The reaction initiated instantaneously and the solution changed to a deep purple color within 5 seconds. The reaction mixture was aged at 15 degrees C for 1 hour before acetone (60 ml) was added to precipitate the gold nanoparticles. The gold nanoparticles (diameter of 7 nm) were collected by centrifugation (8500 rpm, 8 minutes), washed with acetone and redispersed in hexane. Gold nanoparticles (30 mg) with octadecene (10 ml), platinum(II) acetylacetonate (0.1 g), oleylamine (1 ml) and oleic acid (1 ml) were mixed at 120 degrees C. A volume of iron pentacarbonyl (0.03 ml) was added under nitrogen atmosphere, then the temperature was raised to 200 degrees C. The solution was cooled after 30 minutes. Isopropanol (50 ml) was added to precipitate the nanoparticles and the product was collected by centrifuge (6000 rpm, 5 minutes). The resulting gold-iron platinum (FePt3) nanoparticles (had 1.5 nm shell over the 7 nm core) were washed with ethanol and redispersed in hexane.