NOVELTY - Formation of nano-supported catalyst on a substrate comprises configuring a substrate with an electrode immersed in a solvent containing metal salts (A,B) which are soluble in the solvent. A bias voltage is applied to the electrode such that a nano-supported catalyst is at least partly formed from the metal salts on the substrate at the electrode.    USE - To produce nano-supported catalyst for the formation of nanotube (claimed). The nanotube is used as electron emitter in vacuum device such as field emission display, as catalyst for catalytic converter, chemical synthesis, fuel cells, pollution control devices and production of scanning probe microscope tips, and as a resistive material in display such as ballast resistor.    ADVANTAGE - The nano-support provided by the metal oxide support maintains the nanoscale dimensions of the active catalyst particles and prevents the active catalytic particles from coalescing during chemical process for growing carbon nanotubes. The nano-supported catalyst structure controls the density of active catalyst. The metal oxide support prevents the diffusion of poison to nano-supported catalyst and enhances its chemical reactivity. The nano-supported catalyst has a high surface area and a high surface area to volume ratio due to its nano-supported structure. The nano-support renders the particle size independent of nano-supported catalyst layer thickness and temperature thickness. A single wall and multi-wall carbon nanotubes having a uniform structure is selectively and sparsely grown on a micropattern i.e. sub-pixel of quantum dots.    DETAILED DESCRIPTION - Formation of nano-supported catalyst on a substrate comprises configuring a substrate with an electrode immersed in a solvent containing metal salts (A,B) which are soluble in the solvent. A bias voltage is applied to the electrode such that a nano-supported catalyst is at least partly formed from the metal salts on the substrate at the electrode. The catalyst has an active catalytic particle with dimension(s) that is greater than 0.1 nm and less than 500 nm.    An INDEPENDENT CLAIM is also included for formation of nanotube(s) on substrate.    DESCRIPTION OF DRAWING(S) - The figure shows the flow chart for producing nano-supported catalyst.