NOVELTY - A catalyst material is prepared by removing selectively from a surface of a substrate component at least some of metallic crystalline particles, leaving associated with the substrate component at least a portion of the structure lacking crystallinity, where the remaining structure lacking crystallinity associated with the substrate component exhibits catalytic activity.    USE - The assembly is used for the preparation of a catalyst material for a water shift reaction and steam reforming reaction, preferably methanol steam reforming reaction to produce a product, preferably hydrogen. The catalyst material is useful for a chemical apparatus, preferably a chemical reactor or an analytical instrument. (all claimed)    ADVANTAGE - The catalyst material is inexpensive, and has good stability in air and in cyclic operation with respect to the low-temperature water-gas shift reaction. It operates with undiminished efficiency, as compared to the deposited metallic constituent that includes nanocrystalline metallic particles on the same substrates.    DETAILED DESCRIPTION - Preparation of a catalyst material comprises providing a substrate component having a surface; producing on the surface of the substrate component a second component having metallic crystalline particles and a structure lacking crystallinity; and removing selectively from the surface of the substrate component at least some of the metallic crystalline particles, leaving associated with the substrate component at least a portion of the structure lacking crystallinity, where the remaining structure lacking crystallinity associated with the substrate component exhibits catalytic activity.    An INDEPENDENT CLAIM is also included for a method of performing a chemical reaction, comprising providing an amount of a catalyst material comprising a substrate component, and adjacent a surface of the substrate, a metallic residue of a metal deposit, comprising a portion having a structure lacking crystallinity and a portion having crystalline particles, the metallic residue comprising at least some of the structure lacking crystallinity, and being the remnant of the metal deposit from which at least some of the crystalline particles having dimensions greater than a nanometer have been selectively removed; and exposing the catalyst material to a selected chemical substance under predetermined conditions of temperature and pressure, where the selected chemical substance undergoes a catalyzed chemical reaction to produce a product.