A process is disclosed for the direct catalytic production of aqueous solutions of hydrogen peroxide from hydrogen and oxygen in the presence of a small amount of one or more water soluble organic additives (about 0.1 10% by weight). Suitable catalysts include nanometer-sized noble metal catalytic crystal particles. The catalyst particles preferably have a controlled surface coordination number of 2 to increase the selectivity of hydrogen peroxide production. The water soluble additive(s) increases catalytic activity causing significant increases in the apparent first order reaction rate constant for the direct production of aqueous hydrogen peroxide.