Methods for manufacturing supported catalysts and the use of these catalysts in, e.g., the direct synthesis of hydrogen peroxide. The nanocatalyst particles are manufactured from catalyst atoms complexed with organic agent molecules (e.g., polyacrylic acid). The complexed catalyst atoms are heated to cause formation of the nanocatalyst particles. The temperature used to cause formation of the particles is typically greater than 30.degree. C., preferably greater than 50.degree. C, and more preferably greater than 70.degree. C.