TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (Claimed): Preparation of (I) comprises adding a granular substrate to a mixture of gold salt with a solution of a silver salt; adjusting the pH; washing the product remaining with deionized water; and calcining the product resulting from to provide a gold-silver catalyst. Preferred Components: The granular support is a metal oxide (preferably aluminum oxide). The particle size of the catalyst is less than 10 nm. The catalyst comprises less than 10% more gold than silver. The catalyst is a nanocatalyst. Preferred Process: The catalyst is present on a granular support and the pH is adjusted to 4. EXAMPLE - Gold tetrachloroaurate and silver nitrate (each approximately 200 mg) were dissolved separately in deionized water (100 ml). The two solutions were mixed in a beaker. The pH of the resulting mixture was 2.97. Aluminum oxide (5 g) was added to the mixture and the addition of aluminum oxide raised the pH to 3.02. The solution containing the mixture and aluminum oxide was stirred vigorously until the pH of the mixture reached 4, which required mixing for approximately 30 minutes. The increase in pH from 3.02 to 4.0 represented the migration of gold and silver ions to the surface of the aluminum oxide substrate, and accordingly, the aluminum oxide particles were coated with gold and silver ions. The coated aluminum oxide particles were recovered by filtration and washed with excess deionized water to remove nitrate and chlorine ions. Ammonia solution (0.0175M, 5 ml) was added to the granular aluminum oxide particles. Addition of ammonia reduced the gold and silver ions to oxides/hydroxides. The sample was washed with excess deionized water. The washed granules were dried at 105 degrees C for a period of 2 hours. The gold-silver oxides/hydroxide coated aluminum oxide granules were subsequently calcined for 4 hours at 425 degrees C. During the calcination process, the gold-silver oxide/hydroxide was converted to gold-silver nanocatalysts.