Functionalized black liquor-derived porous carbon as an efficient electrocatalyst for hydrogen peroxide production

Distributed production of hydrogen peroxide (H2O2) via 2e-oxygen reduction reaction (ORR) has gained significant attention as a green and safe approach. In this work, black liquor-derived carbon is for the first time functionalized as an electrocatalyst for efficient H2O2 production. The oxygen and boron co-functionalized porous activated carbon (C3-O3-B10) exhibits high activity with almost zero overpotential for 2e-ORR, satisfactory H2O2 selectivity (77%) and good stability. Mechanism investigations reveal that C3-O3-B10 favors catalyzing the 2e-ORR both thermodynamically and kinetically, with a low Tafel slope of 65 mV dec-1, fast charge transfer ability, and low apparent activation energy of 6.7 kJ mol-1@0.4VRHE, owing to the presence of abundant active C=O and B-C2-O functional groups. This work demonstrates that the functionalized black liquor-derived carbon is a reliable and sustainable electrocatalyst to produce H2O2 via ORR, which provides new clues for the utilization of black liquor waste resources in the field of energy conversion and storage.