Plasma-enabled synthesis of ordered PtFe alloy nanoparticles encapsulated with ultrathin N-doped carbon shells for efficient methanol electrooxidation

Scalable production of bifunctional ordered PtFe alloy electrocatalysts for efficient methanol oxidation and hydrogen evolution

“…Notably, the PtFe alloys will not directly participate in the MOR unlike the uncoated Pt-based catalysts due to the active PtFe alloys coated with NC shells. 23 However, the PtFe alloys will provide sufficient electrons to the NC shells' surface as active sites to complete the MOR, and such indirect contact with intermediate CO can well alleviate the Pt-CO poisoning for better catalytic activity and stability. 23,31 The narrow-scan N 1s XPS spectrum of PtFe@HNC can be deconvoluted into three peaks at 398.5 ( pyridinic N, 35%), 399.5 ( pyrrolic N, 16%), and 400.9 (graphitic N, 49%) as shown in Fig.…”

“…3d, which indicates the faster reaction kinetics of the MOR between the PtFe@HNC electrocatalyst and the electrolyte interface. 23 The reason why the PtFe@HNC electrocatalyst exhibits superior activity for the MOR is that the active PtFe alloys can provide sufficient electrons to the NC shells’ surface participating in the reaction, whereas the indirect contact with reactants can alleviate the Pt–CO poisoning. Therefore, the PtFe@HNC electrocatalyst, to the best of our knowledge, has superior mass and specific activities toward the MOR under acidic conditions compared with many other Pt-based electrocatalysts as presented in Fig.…”

“…Pt-based alloy structures have been extensively used to optimize the local electronic structure of Pt, thereby improving the activity and stability of electrocatalysts with a low Pt content such as alloy nanotube structures, 15,16 alloy core/shell structures, 17,18 high-entropy alloy structures, 19,20 and ordered alloy structures. [21][22][23][24] Among these, ordered Pt-based alloy structures have attracted significant attention due to the stronger interatomic interactions, which can greatly improve the electrochemical performance of the catalysts compared to disordered alloy structures. 25,26 In addition, NC shells coated on Pt-based alloys can effectively protect the alloys from unwanted dissolution and avoid degradation in the catalytic activity, which is mainly attributed to the electron transfer from the alloys to the surface of NC shells promoting the reaction called the electronic penetration effect.…”