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 sig-nificant 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, satisfac-tory 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 @ 0.4 VRHE, 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 utili-zation of black liquor waste resources in the field of energy conversion and storage.

Automated summary

In this study, black liquor-derived carbon was functionalized and used as an efficient electrocatalyst for hydrogen peroxide production. The functionalized C3-O3-B10 showed high activity, satisfactory selectivity, and good stability. Mechanism investigations revealed the favorable catalytic properties of C3-O3-B10, making it a reliable and sustainable electrocatalyst for hydrogen peroxide production.