Sulfur-tuned main-group Sb−N−C catalysts for selective 2-electron and 4-electron oxygen reduction

Journal article

The selective oxygen reduction reaction (ORR) is important for various energy conversion processes such as the fuel cells and metal-air batteries for the 4e⁻ pathway and hydrogen peroxide (H₂O₂) electrosynthesis for the 2e⁻ pathway. However, it remains a challenge to tune the ORR selectivity of a catalyst in a controllable manner. Herein, an efficient strategy for introducing sulfur dopants to regulate the ORR selectivity of main-group Sb−N−C single-atom catalysts is reported. Significantly, Sb−N−C with the highest sulfur content follows a 2e⁻ pathway with high H₂O₂ selectivity (96.8%) and remarkable mass activity (96.1 A g⁻¹ at 0.65 V), while the sister catalyst with the lowest sulfur content directs a 4e⁻ pathway with a half-wave potential (E_1/2 = 0.89 V) that is more positive than commercial Pt/C. In addition, practical applications for these two 2e⁻/4e⁻ ORR catalysts are demonstrated by bulk H₂O₂ electrosynthesis for the degradation of organic pollutants and a high-power zinc-air battery, respectively. Combined experimental and theoretical studies reveal that the excellent selectivity for the sulfurized Sb−N−Cs is attributed to the optimal adsorption-desorption of the ORR intermediates realized through the electronic structure modulation by the sulfur dopants.

Authors: Yan, M; Yang, H; Gong, Z; Zhu, J; Allen, C

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Wiley
• Journal: Advanced Materials
• Volume: 36
• Issue: 27
• Article number: 2402963
• Publication date: 2024-04-22
• Acceptance date: 2024-04-10
• DOI: 10.1002/adma.202402963
• EISSN: 1521-4095
• ISSN: 0935-9648
• Pmid: 38616302
• Language: English
• Keywords: catalytic selectivity; main-group metals; oxygen reduction reaction; single atom catalysts; sulfur doping