A Pentagonal Defect-Rich Metal-Free Carbon Electrocatalyst for Boosting Acidic O<sub>2</sub> Reduction to H<sub>2</sub>O<sub>2</sub> Production
Chang Zhang, Wangqiang Shen, Kun Guo, Mo Xiong, Jian Zhang, Xing Lü
Abstract
Metal-free carbon-based materials are considered one of the most promising two-electron oxygen reduction reaction (2e – ORR) electrocatalysts for the green synthesis of hydrogen peroxide (H 2 O 2 ). However, most reported carbon electrocatalysts perform much more effectively in alkalis than in acids. Herein, by creatively using fullerene (C 60 ) as the precursor subject to ammonia treatment, we designed and synthesized a pentagonal defect-rich nitrogen-doped carbon nanomaterial (PD/N–C). It achieves outstanding ORR activity, 2e – selectivity, and stability in acidic electrolytes, surpassing the benchmark PtHg 4 alloy catalyst. Impressively, the flow cell based on the PD/N–C catalyst achieves nearly 100% Faraday efficiency with a remarkable H 2 O 2 yield, representing the best improvement among all the metal-free catalysts. Experimental and theoretical results reveal that such superb 2e – ORR performance of PD/N–C originates from the synergism between pentagonal defects and nitrogen dopants. This work presents an effective strategy for the design and construction of highly efficient acid-resistant carbon electrocatalysts for H 2 O 2 production and beyond.