Modulating the multiple intrinsic properties of platinum–iron alloy nanowires towards enhancing collaborative electrocatalysis

Abstract

The electrocatalytic properties of an alloy can be effectively controlled by adjusting their inherent physical and chemical performance (compositions, lattice strain, facets, etc.) to provide a better surface structure and compositions for efficient electrocatalytic reactions in the cathode and anode of fuel cells. However, it is still a challenge to adjust simultaneously the multiple inherent properties of alloy catalysts to form synergies. Herein, a simple surfactant-free synthetic route was used to develop Pt_nFe_100−n alloy nanowires (NWs) with tunable compositions, lattice strain, enriched-(111) facets and nanoarchitectures with highly exposed active sites. Several characterization results showed that the inherent properties of Pt_nFe_100−n NWs could be manipulated by tuning alloy compositions. The electrochemical results showed that the excellent catalytic performance of Pt_nFe_100−n NWs for the oxygen reduction and alcohol oxidation reactions was in relation to the facets, lattice strain and bimetallic compositions. Interestingly, Pt₇₇Fe₂₃/C NWs with lattice shrinking showed the best activity and stability compared with different compositions and commercial Pt/C catalysts, which was also supported by density functional theory (DFT) calculations. The combination of lattice strain modulation and structural engineering could decrease the adsorption of toxic material and enhance the catalytic performance. This study will provide a new path for the design of robust and active nanoalloy catalysts with multi-performance collaboration for efficient electrocatalytic reactions in the cathode and anode of fuel cells.