Synergistic coupling of Co4N/VN confined in N-doped carbon derived from zeolitic imidazolate frameworks for oxygen reduction reaction

• Published in: Carbon (New York) Vol. 159; pp. 16 - 24
• Main Authors: Zhang, Jie, Chen, Jinwei, Luo, Yan, Chen, Yihan, Li, Zhenjie, Shi, Junjie, Wang, Gang, Wang, Ruilin
• Format: Journal Article
• Language: English
• Published: New York Elsevier Ltd 15.04.2020; Elsevier BV
• Subjects: Carbon; Catalysts; Charge transfer; Charge transport; Chemical synthesis; Cobalt; Coupling; Density functional theory; Electrical resistivity; Electronic structure; Fuel cells; Metal-organic frameworks; Nanocomposites; Nitrogen; Oxygen; Oxygen reduction reactions; Studies; Vanadium; Zeolites
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2019.12.027

A novel nanocomposite (Co–V–N/NC) constituted of cobalt–vanadium nitride (Co–V–N) confined in nitrogen-doped porous carbon (NC) is synthesized and studied as a catalyst for the electrochemical oxygen reduction reaction (ORR). In order to optimize catalytic performance, the intrinsic electronic structure is adjusted by constructing the efficient interface coupling of Co4N/VN in composite. Owing to the strong synergistic coupling effect, the optimized Co–V–N/NC catalyst exhibited the best ORR performance with a limiting current density of 6.1 mA cm−2, and the onset and half-wave potentials of 0.98 and 0.85 V, respectively. The results suggest that the excellent ORR activity of Co–V–N/NC is mainly associated with: (i) effective charge transfer and mass transport between Co4N, VN and NC, (ii) a large number of active sites at the phase boundaries, and (iii) improved electrical conductivity due to incorporated metallic Co4N. Also, Co–V–N/NC catalyst is more durable and methanol-resistant compared to the commercial Pt/C catalyst. Density functional theory suggests the importance of synergistic coupling with Co4N/VN to boost the ORR performance. These results indicate its prospects as efficient, cost-effective and robust catalyst for ORR in alkaline media, which is highly desired for fuel cell applications. [Display omitted]