Synergistic Effect between the Atomically Dispersed Active Site of Fe-N-C and C-S-C for ORR in Acidic Medium

In this occasion, we investigated a sulfur-doped Fe-N-C (Fe/SNC) catalyst with a thiophene-like structure (C-S-C) that reduces the electron localization around the Fe center and improves the interaction with oxygenated species. The observed synergistic effect makes the Fe/SNC catalyst exhibits better ORR activity than sulfur free catalyst (Fe/NC) in 0.5 M H2SO4. The results were published in the journal of Angewandte Chemie International Edition.

Hangjia Shen,  Eduardo Gracia- Espino, Jingyuan Ma, Ketao Zang, Jun Luo,  Le Wang, Sanshuang  Gao, Xamxikamar Mamat, Guangzhi Hu, Thomas Wagberg, and Shaojun Guo.
Angew. Chem. Int. Ed. (2017), DOI: 10.1002/anie.201706602

Abstract

Various advanced catalysts of sulfur doped Fe-N-C materials have been recently designed for oxygen reduction reaction (ORR), however, the enhanced activity is still controversial and usually attributed to differences in surface area, improved conductivity, or to uncertain synergistic effects. Here, a sulfur-doped Fe-N-C catalyst (denoted as Fe/SNC) derived via a template sacrificing method is presented. The incorporated S gives a thiophene-like structure (C-S-C), reduces the electron localization around the Fe center, improves the interaction with oxygenated species, and therefore facilitates the complete 4e- ORR in acid solution. This synergistic effect makes the Fe/SNC catalyst exhibits much better ORR activity than sulfur free catalyst (Fe/NC) in 0.5 M H2SO4.