Enhanced Activity of Small Pt Nanoparticles Decorated with High-Loading Single Fe―N₄ for Methanol Oxidation and Oxygen Reduction via the Assistive Active Sites Strategy

作者：Yan, Wei; Xing, Qianli; Ren, Jianwei; Feng, Hao; Yu, Jinshi; Liu, Hao; Chen, Wenmiao; Wang, Kang; Chen, Yanli^*

来源：Small, 2024, 20(14).

DOI：10.1002/smll.202308473

• methanol oxidation reaction (MOR)
• oxygen reduction reaction (ORR)
• platinum
• porous organic polymers
• single atom catalysts

Decorating platinum (Pt) with a single atom offers a promising approach to tailoring their catalytic activity. In this study, for the first time, an innovative assistive active sites (AAS) strategy is proposed to construct high-loading (3.46wt.%) single Fe & horbar;N-4 as AAS, which are further hybridized with small Pt nanoparticles to enhance both oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR) activities. For ORR, the target catalyst (Pt/HFeSA-HCS) exhibits a higher mass activity (MA) of 0.98 A mg(Pt)(-1) and specific activity (SA) of 1.39 mA cm(Pt)(-2) at 0.90 V versus RHE. As for MOR, Pt/HFeSA-HCS shows exceptional MA (3.21 A mg(Pt)(-1)) and SA (4.27 mA cm(Pt)(-2)) at peak values, surpassing commercial Pt/C by 15.3 and 11.5 times, respectively. The underlying mechanism behind this AAS strategy is to find that in MOR, Fe & horbar;N-4 promotes water dissociation, generating more *OH to accelerate the conversion of *CO to CO2. Meanwhile, in ORR, Fe & horbar;N-4 acts as a competitor to adsorb *OH, weakening Pt & horbar;OH bonding and facilitating desorption of *OH on the Pt surface. Constructing AAS that can enhance dual functionality simultaneously can be seen as a successful "kill two birds with one stone" strategy.

• 单位
  北京科技大学; 中国石油大学（华东）