Coaxial Metal‐Nitrogen–Carbon Single‐Atom Catalysts Boost Acid Hydrogen Peroxide Production
Hongshang Hu, Chang Zhang, Wei Liu, Huiyao Qi, Haoyu Wang, Xinyu Wang, Lilong Zhang, Lei Liu, Lipiao Bao, Muneerah Alomar, Jian Zhang, Xing Lü
Abstract
Abstract Electrosynthesis of hydrogen peroxide (H 2 O 2 ) by two‐electron oxygen reduction reaction (2e − ORR) under acidic conditions is promising. However, constructing a highly efficient acid‐resistant 2e − ORR electrocatalyst is critical but challenging. Herein, a coaxial cobalt single‐atom catalyst on carbon nanotubes (Co SA ‐N‐C/CNTs) is designed and synthesized by an ingenious separation chemical vapor deposition (SCVD) strategy, which achieves higher ORR activity, dominated 2e − selectivity, and superior stability in acid, compared to the counterpart nanoparticle catalyst prepared by traditional mixture pyrolysis. The as‐assembled electrode using Co SA ‐N‐C/CNTs catalyst demonstrates a high H 2 O 2 yield in excess of 2000 mmol g cat −1 h −1 with a Faraday efficiency of >90% over 100 h without decay in a flow cell, as superior to the most reported acidic H 2 O 2 production catalysts. Experimental characterization and theoretical calculations reveal that such excellent 2e − ORR performance of Co SA ‐N‐C/CNTs originate from the combined advantages of strongly coupled coaxial core–shell structure and highly dispersed single‐atom property. Most importantly, a series of other coaxial transition metal single‐atom catalysts (M SA ‐N‐C/CNTs, M = Fe, Cu, or Ni) are prepared through this SCVD strategy, and they all show enhanced ORR performance, demonstrating universality.