Hydrogen peroxide

MOTW update: August 15, 2022

Hydrogen peroxide¹ (H₂O₂) is a powerful oxidizing agent with many industrial applications; and it has familiar uses such as an antiseptic for wounds and a reactant in glow sticks. This month, two articles appeared pertaining to the oxygen reduction reaction (ORR) for synthesizing H₂O₂.

In the first, Curtis P. Berlinguette and several co-workers at the University of British Columbia (Vancouver) and the Canadian Institute for Advanced Research (Toronto) reported a method for directly hydrogenating molecular oxygen without the need for hydrogen gas. They designed a reactor in which hydrogen atoms are electrolytically generated from water in one chamber and then migrate through a palladium foil to a second chamber where they react with incoming oxygen. This process is significantly more efficient than existing indirect hydrogen–oxygen reactor systems.

The second finding was reported by an international team of scientists², who used density functional theory calculations and experimentation to determine structure–function relationships in the single-atom catalysis of ORRs by cobalt–N₄ (CoN₄) complexes, in which N₄ represents four-nitrogen molecules, chiefly tetrapyrrole and tetrapyridine structures. The authors confirmed that pyrrole-type CoN₄ complexes are mainly responsible for the two-electron reduction that produces H₂O₂, whereas pyridine-type complexes catalyze the four-electron ORR that yields water.

1. CAS Reg. No. 7722-84-1.
2. Mingshan Zhu at Jinan University (Guangzhou, China), Emiliano Cortés at Ludwig Maximilian University of Munich (Germany), Min Liu at Central South University (Changsha, China), and colleagues at these institutions and Hunan University (Changsha) and the National Synchrotron Radiation Research Center (Hsinchu, Taiwan).