Safe, One-Pot, Homogeneous Direct Synthesis of H(2)O(2)

[Image: see text] Hydrogen peroxide is an environmentally friendly oxidizing agent but current synthetic methods are wasteful. This is a result of the high flammability of H(2)/O(2) mixtures and/or the requirement for cocatalysts. In this paper, we report the synthesis of H(2)O(2) by means of a homogeneous catalyst, which allows a safe, one-pot synthesis in water, using only H(2) and O(2). This catalyst is capable of removing electrons from H(2), storing them for the reduction of O(2), and then permitting the protonation of the reduced oxygen to H(2)O(2). The turnover number (TON) is 910 under an H(2)/O(2) (95/5) atmosphere (1.9 MPa) for 12 h at 23 °C, which is the highest of any homogeneous catalyst. Furthermore, we propose a reaction mechanism based on two crystal structures.