Synthesis and electrocatalytic performance of MWCNT-supported Ag@Pt core–shell nanoparticles for ORR

Ag@Pt core–shell nanoparticles with different Ag/Pt ratios were supported on multi walled carbon nanotubes (MWCNTs) and used as electrocatalysts for PEMFC. The morphology of the electrocatalyst samples was characterized by XRD and HRTEM. It was found that the Ag@Pt/MWCNTs catalyst exhibited a core–shell nanostructure. And the CV and LSV results demonstrated that such core–shell materials exhibited attractive electrocatalytic activity. Moreover, the specific electrochemically active area (EAS) of the Ag@Pt/MWCNTs catalyst is 70.63 m2 g−1, which is higher than the values reported in the literature.

Graphical abstractAn Ag@Pt/MWCNTs electrocatalyst was synthesized by a colloidal method and a chemical reduction method with NaBH4 and ethylene glycol as reducing agents. In this process, oxygen functional groups (COOH–, OH–, COH–) on the surface of MWCNTs become active sites which can absorb Ag+, therefore Ag nanoparticle can form easily and act as the core. The Pt covering the Ag nanoparticles acts as the shell. Pt crystallite and Ag crystallite are all with face-centered cubic structure, which is in favor of the growth of Pt on the Ag surface. Multi-walled carbon nanotubes with their large surface area and good electrical conductivity can be a good support for electrocatalyst.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► MWCNTs supports Ag@Pt core–shell nanoparticles electrocatalysts were synthesized. ► They were synthesized by a colloidal method and a chemical reduction method. ► The average particle size of the Ag@Pt core–shell nanoparticles was 12–17 nm ► The largest specific electrochemically active area (EAS) of it was 70.63 m2 g−1.