NOVELTY - A method (m1) of forming elongated nanoparticles on carbon support, involves functionalizing a surface of the carbon support; and producing elongated nanoparticles of a first noble metal on the surface of the functionalized carbon support by pulse potential deposition.    USE - For forming elongated nanoparticles on carbon support used in energy conversion devices (claimed) and for producing catalytic electrodes for electrochemical energy conversion in devices such as fuel cells and metal-air batteries.    ADVANTAGE - Prior to electrochemical deposition, the carbon support may be functionalized by oxidation, thus making the manufacturing process simple and cost-effective. The generated elongated nanoparticles are covalently bound to the carbon support and can be used directly in electrocatalysis. The process provides elongated noble-metal nanoparticles with high catalytic activities and improved durability in combination with high catalyst utilization since the nanoparticles are deposited and covalently bound to the carbon support in their final position and will not change in forming an electrode assembly. The production of nanoparticles directly on the functionalized high surface area support permits deposition of nanoparticles at their final position on the electrode surface that will not change in forming the membrane electrode assembly, thus maximizing the available catalytically active surface area and improving stability. The use of the method facilitates a more efficient, expedient, and cost-effective process for producing catalytic electrodes for electrochemical energy conversion.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) method of forming core-shell nanoparticles, involving producing the elongated nanoparticles according to method (m1); and forming a shell layer of a second noble metal which is more noble than the first noble metal on an external surface of the nanoparticles to form core-shell nanoparticles;    (2) catalyst particle comprising a carbon support having a high surface area per unit mass; and an elongated metal nanoparticle covalently bound to the carbon support;    (3) electrode comprising a carbon support having a high surface area per unit mass; and an elongated metal nanoparticle covalently bound to the carbon support;    (4) an energy conversion device comprising a first electrode; conducting electrolyte; and second electrode, where at least one of the first or second electrodes comprises the catalyst particles.