A Selective Copper Based Oxygen Reduction Catalyst for the Electrochemical Synthesis of H(2)O(2) at Neutral pH

H(2)O(2) is a bulk chemical used as “green” alternative in a variety of applications, but has an energy and waste intensive production method. The electrochemical O(2) reduction to H(2)O(2) is viable alternative with examples of the direct production of up to 20% H(2)O(2) solutions. In that respect, we found that the dinuclear complex Cu(2)(btmpa) (6,6’‐bis[[bis(2‐pyridylmethyl)amino]methyl]‐2,2’‐bipyridine) reduces O(2) to H(2)O(2) with a selectivity up to 90 % according to single linear sweep rotating ring disk electrode measurements. Microbalance experiments showed that complex reduction leads to surface adsorption thereby increasing the catalytic current. More importantly, we kept a high Faradaic efficiency for H(2)O(2) between 60 and 70 % over the course of 2 h of amperometry by introducing high potential intervals to strip deposited copper ((dep)Cu). This is the first example of extensive studies into the long term electrochemical O(2) to H(2)O(2) reduction by a molecular complex which allowed to retain the high intrinsic selectivity of Cu(2)(btmpa) towards H(2)O(2) production leading to relevant levels of H(2)O(2).