TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preparation (claimed): Preparation of the catalyst involves: preparing a thermolysis mixture comprising a salt of the metal where the metal is in the +5 valence state, a platinum (Pt) compound, and a basic salt selected to decompose into gaseous byproducts at a thermolysis temperature; and heating the thermolysis mixture in a reducing atmosphere to the thermolysis temperature where the thermolysis temperature is less than 900 degrees C. Preferred Method: The step of preparing the thermolysis mixture involves grinding the thermolysis mixture before the heating. The reducing atmosphere comprises hydrogen and an inert gas. The thermolysis temperature is 800 degrees C. The method involves: preparing an initial mixture comprising the salt of the metal and the basic salt; and heating the initial mixture in an ambient atmosphere to a temperature below the thermolysis temperature. The initial mixture comprises amorphous metal oxide. The method involves: adding the Pt compound to the initial mixture after heating the initial mixture to preparing the thermolysis mixture. The atomic ratio of Pt to niobium (Nb) in the thermolysis mixture is greater than or equal to 0.4. Preferred Components: The average crystallite size of the intermetallic phase is 0-35 (preferably 0-15) nm. The Pt3Nb intermetallic phase has an orthorhombic structure with lattice parameters a of 4.5700 Angstrom , b of 5.5400 Angstrom , and c of 4.8800 Angstrom . The metal is niobium (Nb). The salt of the metal is selected from niobium oxalate and niobium chloride (preferably niobium oxalate). The Pt compound is selected from tetraamine platinum(II) nitrate, tetraamine platinum(II) chloride hydrate, platinum(II) chloride monohydrate, platinum acetylacetonate, diiminedinitrito platinum(II) and dihydrogenhexachloroplatinate(IV) hexahydrate (preferably tetraamine platinum(II) nitrate and dihydrogenhexachloroplatinate(IV) hexahydrate). The basic salt is selected from ammonium bicarbonate, ammonium carbonate, ammonium acetate, ammonium oxalate, ammonium sulfate, or ammonium hydroxide (preferably ammonium bicarbonate). SPECIFIC COMPOUNDS - Pt3Nb-NbO2 compound is specifically claimed as the catalyst.    EXAMPLE - Pt3Nb-NbO2 was prepared by first grinding together 1 mmol of Nb(HC2O4)5.6H2O (niobium oxalate) and 0.43 mmol of Pt(NH3)4(NO3)2 (tetraamine platinum(II) nitrate) in the presence of 7.5 mmol NH4HCO3 (ammonium bicarbonate). The ground powder mixture was then heated in an argon atmosphere at 400 degrees C for 1 hour. The intermediate reaction product here comprised amorphous Nb oxide. The mixture was then heated further in a reducing atmosphere comprising a mixture of hydrogen and argon at 800 degrees C for 1 hour. During this thermolysis step, both Pt alloying with Nb, and NbO2 semiconductive phase formation occurred. The synthesized Pt3Nb intermetallic phase had an orthorhombic structure.