Carbon doped cobalt nanoparticles stabilized by carbon shell for highly efficient and stable oxygen reduction reaction. (30th August 2022)

• Record Type: Journal Article
• Authors: He, Miao; Song, Shaojia; Wang, Ping; Fang, Zhao; Wang, Weiwei; Yuan, Xilin; Li, Chenyu; Li, Huan; Song, Weiyu; Luo, Dan; Li, Zhenxing
• Is Part Of: Carbon. Volume 196(2022)
• Page Start: 483
• Page End: 492
• Publication Date: 2022-08-30
• Subjects: C-doped Co nanoparticles -- Oxygen evolution reaction -- Oxygen reduction reaction -- Zinc-air batteries -- Density functional theory; Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2022.05.019
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: The oxygen reduction reaction (ORR) is a key reaction in metal-air batteries and fuel cells. Herein, a novel carbon-doped Co nanoparticle coated with a carbon layer supported on the ordered macroporous titanium oxide (C-doped Co@C@TiO2 ) is designed as the highly efficient and stable ORR catalysts. The C-doped Co@C@TiO2 achieves the superior catalytic activity with an onset potential of 0.867 V and a limiting current density of −6.59 mA cm −2, which is much lower than the commercial Pt/C (−5.93 mA cm −2 ). The turnover frequency (TOF) of the C-doped Co@C@TiO2 at the potential of 0.3 V (0.091 s −1 ) is nearly four times than the commercial Pt/C (0.025 s −1 ). This outstanding catalytical performance is attributed to the unique C-doped Co layer in Co nanoparticles, which can stable the OOH* and promote the desorption of OH*, and accelerate the catalyst surface regeneration in ORR. Meanwhile, the outer C layer with mesoporous channels can improve the stability and poisoning resistant of the C-doped Co nanoparticles, and the C-doped Co@C@TiO2 still retains 98% of the current density after the reaction for 60 h. It is worth noting that the assembled zinc-air battery with C-doped Co@C@TiO2 as the air cathode exhibits an ultra-high open circuit voltage of 1.51 V and an excellent durability of more than 41.6 days. This work provides one of the most promising non-noble metal-based catalysts for efficient and stable oxygen reduction reaction. Graphical abstract: Image 1 Highlights: The C-doped Co@C@TiO2 achieves the superior catalytic activity with an onset potential of 0.867 V and a limiting current density of −6.59 mA cm −2 . The unique C-doped Co layer in Co nanoparticles can stable the OOH* and promote the desorption of OH*, and accelerate the catalyst surface regeneration in ORR. The outer C layer with mesoporous channels can improve the stability and poisoning resistant of the C-doped Co nanoparticles. The C-doped Co@C@TiO2 has a current density retention rate of more than 98% after 60 h current-time test, which is significantly better than commercial Pt/C (66%). The znic-air battery with C-doped Co@C@TiO2 as the air cathode has a cycle stability of 41.6 days.