First synthesis of RuSn solid-solution alloy nanoparticles and their enhanced hydrogen evolution reaction activity

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Solid-solution alloys of platinum group metals and p-block metals are promising for tunable electronic structures.
• Ruthenium (Ru) and Tin (Sn) based alloys are of interest for catalytic applications.

Purpose of the Study:

• To synthesize novel solid-solution Ruthenium-Tin (RuSn) alloy nanoparticles (NPs).
• To investigate the hydrogen evolution reaction (HER) performance of these RuSn alloy NPs.
• To understand the electronic structure and charge transfer mechanisms influencing their catalytic activity.

Main Methods:

• Electrochemical cyclic voltammetry sweeping of RuSn@SnO NPs for synthesis.
• High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and energy-dispersive X-ray spectroscopy (EDX) for structural and compositional analysis.
• Hard X-ray photoelectron spectroscopy (HAXPES) and X-ray absorption near-edge structure (XANES) for electronic structure investigation.

Main Results:

• Homogeneous distribution of Ru and Sn elements in the synthesized alloy NPs was confirmed.
• RuSn alloy NPs exhibited significantly improved HER performance compared to monometallic Ru NPs and commercial Pt NPs/C.
• The overpotentials for Ru_0.87Sn_0.13 NPs/C to achieve 10 mA cm^-2 were 33.19 mV, outperforming Ru NPs/C (53.53 mV) and Pt NPs/C (55.77 mV).

Conclusions:

• The downward shift of the Ru d-band center in RuSn alloy NPs, attributed to charge transfer from Sn to Ru, effectively regulates the adsorption energy of hydrogen intermediates (H_ads).
• These findings highlight the potential of RuSn solid-solution alloy NPs as highly efficient electrocatalysts for the hydrogen evolution reaction.