Secondary reduction strategy synthesis of Pt–Co nanoparticle catalysts towards boosting the activity of proton exchange membrane fuel cells (Open Access)--颗粒学报PARTICUOLOGY

Yang, B., Yu, X., Hou, J., & Xiang, Z. (2023). Secondary reduction strategy synthesis of Pt–Co nanoparticle catalysts towards boosting the activity of proton exchange membrane fuel cells. Particuology, 79, 18-26. https://doi.org/10.1016/j.partic.2022.11.010

Secondary reduction strategy synthesis of Pt–Co nanoparticle catalysts towards boosting the activity of proton exchange membrane fuel cells (Open Access)

Bolong Yang, Xiaogang Yu, Jingkui Hou, Zhonghua Xiang ^*

State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, China

10.1016/j.partic.2022.11.010

Volume 79, August 2023, Pages 18-26

Received 31 October 2022, Revised 18 November 2022, Accepted 20 November 2022, Available online 15 December 2022, Version of Record 24 January 2023.

E-mail: xiangzh@mail.buct.edu.cn

Highlights

• Highly ordered Pt₃Co nanoparticles were prepared by a two-step reduction strategy.

• Pt₃Co/C has advantages of high reactivity, fast mass transfer and lower resistance.

• The half wave potential of Pt₃Co/C reached 0.87 V, showing excellent ORR performance.

• The mass activity reached 0.67 A mgpt⁻¹, exceeding the DOE standard (0.44 A mgpt⁻¹).

Abstract

Based on the volcanic relationship between catalytic activity and key adsorption energies, Pt–Co alloy materials have been widely studied as cathode oxygen reduction reaction (ORR) catalysts in proton exchange membrane fuel cells (PEMFCs) due to their higher active surface area and adjustable D-band energy levels compared to Pt/C. However, how to balance the alloying degree and ORR performance of Pt–Co catalyst remains a great challenge. Herein, we first synthesized a well-dispersed Pt/Co/C precursor by using a mild dimethylamine borane (DMAB) as the reducing agent. The precursor was calcined at high temperature under H2/Ar mixed gas by a secondary reduction strategy to obtain an ordered Pt₃Co intermetallic compound nanoparticle catalyst with a high degree of alloying. The optimization of electronic structure due to Pt–Co alloying and the strong metal-carrier interaction ensure the high kinetic activity of the cell membrane electrode. Additionally, the high degree of graphitization increases the electrical conductivity during the reaction. As a result, the activity and stability of the catalyst were significantly improved, with a half-wave potential as high as 0.87 V, which decreased by only 20 mV after 10000 potential cycles. Single-cell tests further validate the high intrinsic activity of the ordered Pt3Co catalyst with mass activity up to 0.67 A mgpt⁻¹, exceeding the United States Department of Energy (US DOE) standard (0.44 A mgpt⁻¹), and a rated power of 5.93 W mgpt⁻¹.

Graphical abstract

Keywords

Ordered Pt₃Co nanoparticle; Low platinum catalyst; Secondary reduction strategy; Oxygen reduction reaction; Proton exchange membrane fuel cells

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