Sb2S3-templated synthesis of sulfur-doped Sb-N-C with hierarchical architecture and high metal loading for H2O2 electrosynthesis
Minmin Yan, Zengxi Wei, Zhichao Gong, Bernt Johannessen, Gonglan Ye, Guanchao He, Jingjing Liu, Shuangliang Zhao, Chunyu Cui, Huilong Fei
Abstract
Abstract Selective two-electron (2e − ) oxygen reduction reaction (ORR) offers great opportunities for hydrogen peroxide (H 2 O 2 ) electrosynthesis and its widespread employment depends on identifying cost-effective catalysts with high activity and selectivity. Main-group metal and nitrogen coordinated carbons (M-N-Cs) are promising but remain largely underexplored due to the low metal-atom density and the lack of understanding in the structure-property correlation. Here, we report using a nanoarchitectured Sb 2 S 3 template to synthesize high-density (10.32 wt%) antimony (Sb) single atoms on nitrogen- and sulfur-codoped carbon nanofibers (Sb-NSCF), which exhibits both high selectivity (97.2%) and mass activity (114.9 A g −1 at 0.65 V) toward the 2e − ORR in alkaline electrolyte. Further, when evaluated with a practical flow cell, Sb-NSCF shows a high production rate of 7.46 mol g catalyst −1 h −1 with negligible loss in activity and selectivity in a 75-h continuous electrolysis. Density functional theory calculations demonstrate that the coordination configuration and the S dopants synergistically contribute to the enhanced 2e − ORR activity and selectivity of the Sb-N 4 moieties.