NOVELTY - A substrate for use in micro-component reactors comprises two opposite surfaces (1A, 1B). The first surface comprises ruthenium; rhodium; palladium; silver; iridium; platinum; gold; and/or oxides of cerium oxide, aluminum, tin, manganese, copper, cobalt, nickel, praseodymium, and/or terbium. The second surface comprises ruthenium, rhodium, palladium, silver, iridium, platinum, and/or gold.    USE - The substrate is used in the manufacture of a micro component micro-channel catalytic heat exchange device (claimed), particularly as a separator or wavy plate for a micro-component reactor.    ADVANTAGE - The substrate provides a two-sided micro-channel with a first surface having a porous fine particle coating of a mixture of metal oxides and noble metals, having good mechanical adhesion to a substrate surface and stability properties and surface characteristics useful for catalytic reactor applications.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following:    (a) providing different catalyst surfaces on the opposite surface sides of a substrate, which comprises thermal spraying one surface of the substrate with particulates of a metal hydroxide, metal carbonate, and/or metal nitrite particles and a noble metal, noble metal hydroxide, noble metal carbonate, or noble metal nitrate to produce a first catalyst composition on it; and coating a surface of the substrate opposite the surface thermally sprayed with particulates by a physical deposition process with ruthenium, rhodium, palladium, silver, iridium, platinum, and/or gold to produce a second catalyst composition on it; and    (b) the production of a micro-channel catalytic device, which comprises pre-forming a substrate with longitudinal folds spaced a predetermined distance apart corresponding to predetermined apexes of micro channels having a predetermined depth; and providing different catalyst surfaces on the opposites surface sides of a substrate.    DESCRIPTION OF DRAWING(S) - The figure is a representation of a shaped and coated thin plate substrate formed into a wavy plate separator for a micro channel separator for a micro component reactor, where the opposite sides of the shaped plate are surfaced with different catalysts.    Opposite surfaces (1A, 1B)    Apexes of the folds (A1-A4)