High-loaded sub-6 nm Pt1Co1 intermetallic compounds with highly efficient performance expression in PEMFCs. Issue 1 (6th December 2021)

• Record Type: Journal Article
• Authors: Cheng, Qingqing; Yang, Shuai; Fu, Cehuang; Zou, Liangliang; Zou, Zhiqing; Jiang, Zheng; Zhang, Junliang; Yang, Hui
• Is Part Of: Energy & environmental science. Volume 15:Issue 1(2022)
• Page Start: 278
• Page End: 286
• Publication Date: 2021-12-06
• Subjects: Energy conversion -- Periodicals; Fuel switching -- Periodicals; Environmental sciences -- Periodicals; Environmental chemistry -- Periodicals; 333.79
• DOI: 10.1039/d1ee02530a
• Languages: English
• ISSNs: 1754-5692

Abstract

Abstract : High-loaded Pt1Co1-IMC@Pt/C catalyst enables high power PEMFCs, meeting the practical application requirement in electric vehicles. Abstract : High-loaded oxygen reduction reaction (ORR) Pt intermetallic compounds with high performance expression under PEMFC operating conditions are prerequisite for practical application. Nevertheless, high metal-loading would lead to the severe agglomeration and nonuniformity of nanoparticles, imposing an enormous challenge on efficient synthesis. Herein we present a cobalt oxide aided structural evolution strategy to controllably synthesize high-loaded (44.7 wt%) sub-6 nm Pt1Co1 intermetallic compounds with a Pt-rich shell (Pt1Co1-IMC@Pt). Experiments and theory explicitly reveal that the ordered arrangement of Pt–Co atoms endows surface Pt with a lowered d band centre and enhanced oxidation-resistance of Pt/Co sites, thus simultaneously boosting the ORR activity and durability. The preeminent intrinsic ORR activity on an optimized catalyst reaches a mass activity as high as 0.53 A mg(Pt) −1 @0.90 V RHE −1 (MA@0.9 V) in rotating disk electrode measurements. PEMFCs with such a catalyst deliver record-high power density (2.30/1.23 W cm −2 under H2 –air/O2 conditions at 80 °C) and extraordinary stability, ranking the highest fuel cell performance among the Pt-based electrocatalysts. Significantly, the MA@0.9 V calculated from fuel cell attains 0.46 A mg(Pt) −1, exceeding the 2020 DOE target (0.44 A mg(Pt) −1 ) and very close to the intrinsic value, definitely confirming the superiority of high-loaded Pt1Co1-IMC@Pt/C in activity expression under fuel cell conditions. This study paves a new way for the future practical application of low-Pt catalysts in PEMFCs.