Highly efficient PtCo nanoparticles on Co–N–C nanorods with hierarchical pore structure for oxygen reduction reaction. (26th April 2021)

• Record Type: Journal Article
• Authors: Mo, Rongcheng; Zhang, Xiaoran; Chen, Zhenyu; Huang, Shangli; Li, Yanjie; Liang, Lizhe; Tian, Zhi Qun; Shen, Pei Kang
• Is Part Of: International journal of hydrogen energy. Volume 46:Number 29(2021)
• Page Start: 15991
• Page End: 16002
• Publication Date: 2021-04-26
• Subjects: Metal-organic frameworks -- Co–N–C electrocatalyst -- PtCo nanoparticles -- Oxygen reduction reaction -- Fuel cells; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2021.02.119
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Developing platinum-based nanoparticles on carbon catalysts with high activity and stability for oxygen reduction reaction (ORR) is of great significance for the practical application of fuel cells. Herein, a synchronous strategy of preparing nano-sized PtCo supported on atomic Co and N co-doped carbon nanorods (PtCo/Co–N–C NR) was developed to replace the conventional method of impregnating Pt sources into ready-made carbon materials, in which metal-organic frameworks (MOFs) with Co and Zn ions of rhombic dodecahedron were first prepared using 2-methylimidazole as building block and then their morphology was transformed into porous nanorods via the reduction of Co ions to Co–B–O complex in the MOFs by NaBH4 ; subsequently, Pt was deposited on the Co–Zn MOF nanorods through the displacement reaction of PtCl6 2 - and metallic Co and coordination between MOF and PtCl6 2 - ; after pyrolysis and acid-leaching process, highly dispersed PtCo/Co–N–C NR was obtained. Attributed to its unique characteristics of hierarchical pore structure, uniform PtCo alloy nanoparticles with the average size of 7.0 nm and strong supporting interaction effect, the catalyst exhibits high ORR activity and stability with the mass activity of 577.0 mA mg −1 Pt and specific activity of 1.4 mA cm −2 at 0.9 V vs RHE in 0.1 M HClO4, which is about 3.6 times and 3.5 times high than that of commercial Pt/C catalyst respectively. This strategy would provide a flexible route to develop highly active and stable ORR electrocatalysts with various morphologies for optimizing the exposure of active sites. Graphical abstract: Image 1 Highlights: A synchronous synthesis was developed to prepare nano-sized PtCo/Co–N–C nanorods using CoZn@MOF as precursor. The formation of Co–B–O complex in CoZn@MOF by NaBH4 is a critical step for specific morphology. The PtCo/Co–N–C NR exhibit efficient catalytic activity and stability towards ORR. This strategy is a promising way to synthesize efficient and robust electrocatalysts.