Efficient oxygen reduction to H2O2 in highly porous manganese and nitrogen co-doped carbon nanorods enabling electro-degradation of bulk organics

The direct synthesis of hydrogen peroxide using sustainable energy and molecular oxygen is a promising alternative approach to the conventional batch synthesis. Here we present a manganese and nitrogen co-doped carbon material which catalyzes the selective reduction of dioxygen in an acidic environment to hydrogen peroxide. The onset potential is close to 0.7 V, with >98% H2O2 selectivity in the range of 0.7-0.5 V vs RHE. This is the highest reported to date, outperforming many bimetallic noble metal catalysts. Besides, this doped carbon material is hierarchically porous, featuring both a large mesopore volume (4.54 mL g(-1)) and a high specific surface area (1333 m(2) g(-1)). This enables the effective adsorption of bulky organics such as methylene blue (385 mg g(-1)). Combined with the formation of hydroxyl radicals during electrochemical H2O2 generation, this material also enables the efficient electrochemical degradation of methylene blue, as evidenced by in situ UV-vis spectrometry. (C) 2019 Elsevier Ltd. All rights reserved.