The direct synthesis of hydrogen peroxide from hydrogen and oxygen has been explored for decades, although it has been challenged by the inherent risk of handling explosive gas mixture and mass transfer resistance for its nature of gas-liquid-solid reaction. Using newly designed and fabricated glass microreactors, we successfully handle the reaction with promising productivity. 10 wt.% aqueous hydrogen peroxide solution is obtained at room temperature (ca. 293 K), 1 MPa. It owes to proper gas- and liquid handling as well as characteristics of microreactor technology (rapid heat/mass transfer), and proper preparation of the catalysts. (C) 2012 Elsevier B.V. All rights reserved.