PtCuFe alloy nanochains: Synthesis and composition-performance relationship in methanol oxidation and hydrogen evolution reactions

The controllable synthesis of 1-dimensional (1D) multi-metal Pt-based alloys, with enhanced electro-chemical properties remains a challenge, despite the wide application of Pt-based catalysts in fuel cells and in the hydrogen evolution reaction (HER). Herein, we fabricate PtCuFe alloy nanochains (NCs) that have a tunable composition by flexibly adjusting the molar ratios of the metal precursors. It was found that Cu2+ is key in the formation of 1D NCs, as confirmed by transmission electron microscopy character-izations. In addition, the alloyed Fe can further increase the content of the metallic state of Cu in the PtCuFe NCs. The as-prepared PtCuFe NCs exhibited higher catalytic activity and stability than those of the Pt nanoparticles (NPs), PtFe NPs, and PtCu NCs, for the methanol oxidation reaction (MOR) and HER. Additionally, the composition-performance relationship of PtCuxFey NCs toward the MOR and HER were investigated. The hybrid density functional theory calculation and analysis showed that the 1D PtCuFe NCs have a lower lowest unoccupied molecular orbital (LUMO) than those of the 2-and 3 -dimensional PtCuFe, verifying that the 1D PtCuFe NCs exhibit the highest activity for the MOR. This work has established a new method for the controllable synthesis of multi-metal Pt-based NCs/alloy catalysts and their subsequent applications in other electro-catalytic reactions.(c) 2022 Elsevier Inc. All rights reserved.

Automated summary

This study successfully synthesized tunable PtCuFe alloy nanochains by adjusting the molar ratios of metal precursors. These nanochains exhibited higher catalytic activity and stability compared to Pt nanoparticles, PtFe nanoparticles, and PtCu nanochains. Additionally, it was found that 1D PtCuFe nanochains showed the highest activity for the methanol oxidation reaction. This work establishes a foundation for the controllable synthesis of multi-metal Pt-based nanochains/alloy catalysts and their applications in other electro-catalytic reactions.