TECHNOLOGY FOCUS - METALLURGY - Preferred Process: The process further comprises, for each powder in the array, reducing the precipitated metal on the particulate support; and forming an alloy on the particulate support, where the alloy comprises metals derived from the pre-deposited material and the precipitated metal or derived from first and second precipitated metals. The precipitated metal is reduced to its metallic oxidation state. The removal of heat from the dispersion freezes the solution. The separation of the particulate support from the solution, after the removing step is complete, is by freeze-drying. The dispersions are formed using a solution comprising a first dissolved metal and a second dissolved metal, both of which are precipitated on the particulate support upon removal of heat from the dispersion. Each of the dispersions is within a container having an exterior. Heat is removed from the dispersions in the removing step by contacting the exterior of each container with a cooling medium. The volumetric ratio of particulate support to solvent is greater than or equal to 1:8, preferably greater than or equal to 1:5 or greater than or equal to 1:2. The particulate support is uniformly dispersed in the solution.Preferred Component: The particulate support comprises a pre-deposited material from a pre-deposited metal compound, and/or a pre-deposited metal in its metallic oxidation state. The dispersion is a suspension. The combinatorial library of supported metal alloy powders may comprise an array comprising supported metal alloy powder members. Each of the supported metal alloy powders comprises a particulate support (2); deposits (3) comprising a metal alloy on the particulate support, where the metal alloy comprises a non-noble metal; a loading of deposits on the particulate support of greater than or equal to 20 wt.%; an average deposit size that is not greater than 10 nm; and a deposit size distribution where greater than or equal to 70% of the metal alloy deposits are between 50-150% of the average metal alloy deposit size. The supported metal alloy powder members of the array are different from each other w.r.t one or more characterizing features from chemical or physical properties of the particulate support; chemical or physical properties of the metal alloy on the particulate support; the extent of loading of the deposits on the particulate support; or the average deposit size on the particulate support. The loading of the deposits is 20-60 (preferably 20-40) wt.% of the particulate support. The average deposit size is not greater than 5 (preferably not greater than 2 or 5-10) nm. The deposit size distribution is such that greater than or equal to80% of the metal alloy deposits are between 75-125% of the average metal alloy deposit size.Preferred Property: The dispersions have a viscosity of 5000 mPa-second.