NOVELTY - Inverse micelle-based method for forming nanoparticles on supports, comprises: dissolving a polymeric material in a solvent, where polymeric micelles are formed to provide a micelle solution; dissolving a nanoparticle source in the micelle solution, where many loaded micelles (A) having a nanoparticle ion core and an outer polymeric coating layer are formed in the solution; applying (A) to a surface of a support, and removing the polymeric coating layer from (A) while forming nanoparticles from the nanoparticle ion cores to expose at least a portion of the nanoparticles.    USE - The nanoparticles on support are useful for gas sensing, photocatalysis, and other applications where the production of nanowires with tunable width and interwire distance is desired. The catalyst is useful for low and high temperature catalysis applications (e.g. an automobile's catalytic converter and turbines). (I) is useful as catalyst for: carbon monoxide (CO) oxidation and alcohol (methanol, ethanol, propanol and butanol) decomposition and oxidation; selective nitrogen oxide (NOx) reduction; and high-temperature decomposition of sulfuric acid to produce hydrogen (platinum/titanium dioxide).    ADVANTAGE - The method provides thermally stable nanoparticles on supports, where the nanoparticles have narrow size distributions, homogeneous dispersions e.g. periodicity, and regular shapes on a variety of support materials and support types including nanocrystalline powder supports, thin film and single crystal supports. The catalyst is resistant to coarsening at higher temperature. The nanoparticles surfaced articles are applicable for high temperature catalysis, low-cost large scale patterning of oxide surfaces to obtain nanowires, production of high surface area nanoparticles (metal or semiconductor) and high surface area nanosupports (metal oxide nanowires) in a single step.    DETAILED DESCRIPTION - Inverse micelle-based method for forming nanoparticles on supports, comprises: dissolving a polymeric material in a solvent, where polymeric micelles are formed to provide a micelle solution; dissolving a nanoparticle source in the micelle solution, where many loaded micelles having a nanoparticle ion core and an outer polymeric coating layer that includes many polymeric ligands are formed in the micelle solution; applying the loaded micelles to a surface of a support, and removing the polymeric coating layer from the loaded micelles while forming nanoparticles from the nanoparticle ion cores to expose at least a portion of the nanoparticles. INDEPENDENT CLAIMS are included for a supported catalyst, comprising: either a support comprising a nanocrystalline powder, a thin film, or a single crystal, many metal nanoparticles having a median size of 0.5-25 nm, a size distribution having a standard deviation of less than or equal to 0.1 of the median size on or embedded in the support, where the metal nanoparticles are dispersed from one another and positioned in a periodic arrangement, where the metal nanoparticles maintain the periodic arrangement and the size distribution following heat treatments of at least 1000 degrees C; or a support comprising an oxide thin film, or a single crystal having an oxide surface and many metal nanoparticles comprising platinum or palladium having a median size of 0.5-5 nm.    DESCRIPTION OF DRAWING(S) - The figure shows a flow chart for an inverse micelle-based method for forming nanoparticles on supports.