Robinin/silver colloidal nanoparticle catalyst is prepared by dissolving 1.07 g robinin in a beaker containing 800 ml DI water at room temperature. 1 N NaOH solution is added with stirring to adjust the solution pH to 11. In a separate beaker, 1.42 g silver p-toluenesulfonate is dissolved in 40 ml DI water. The silver ion solution is added to the robinin solution with vigorous stirring. The molar ratio of silver metal to robinin is 1:0.28. The beaker containing the aqueous catalyst solution is placed in a 50° C. water bath for 12 hours to test its stability. After 12 hours the solution is observed and no precipitate is expected indicating that the catalyst is still stable.
