Yan Zhao, Shixu Song, Jing Liu, Xuejing Cui, Luhua Jiang*

Nanomaterials & Electrocatalysis Laboratory, College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, P. R. China

*Email: luhuajiang@qust.edu.cn

Abstract

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 co-functionalized porous activated carbon (C₃-O₃-B₁₀) optimized with oxygen and boron exhibits high activity with almost zero overpotential, satisfactory H₂O₂ selectivity (77%) and good stability. Mechanism investigations reveal that C₃-O₃-B₁₀ favors catalyzing a 2e-ORR pathway 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@0.4V_RHE, 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 in the production of H₂O₂, which provides new clues for the utilization of black liquor waste resources in the field of energy conversion and storage.

Keywords: Black liquor-derived carbon; functionalized carbon; oxygen electroreduction reaction; hydrogen peroxide production; oxygen and boron co-doping.

https://doi.org/10.1016/j.jallcom.2023.171264