Motif Editing Reveals Hidden Active Sites in Atomically Precise Metal Nanoclusters for Enhanced Electrocatalysis

Area of Science:

• Nanomaterials Science
• Catalysis
• Surface Chemistry

Background:

• Metal nanoclusters offer precise catalytic platforms but often rely on bulky ligands for stability, hindering active site accessibility.
• The trade-off between cluster stability and catalytic performance due to ligand bulk is a key challenge.

Purpose of the Study:

• To develop a motif-by-motif surface editing strategy for atomically precise metal nanoclusters.
• To expose catalytic sites while maintaining cluster integrity.
• To enhance catalytic performance by optimizing surface structure.

Main Methods:

• Selective replacement of bulky Au2(pMBA)3 motifs with compact Cu-(pMBA)3 units on [Au25(pMBA)18]- nanoclusters.
• Utilizing in situ absorption and mass spectrometry to elucidate the stepwise motif exchange mechanism.
• Employing spectroscopy and density functional theory (DFT) for mechanistic and performance analysis.

Main Results:

• Successful synthesis of [Au13Cu4(pMBA)12]3- nanoclusters with a symmetric, open-surface architecture via a novel stepwise motif exchange.
• Demonstrated a 180-fold enhancement in hydrogen evolution turnover frequency (18.8 s-1) compared to the parent nanocluster (0.1 s-1).
• Attributed performance enhancement to increased Au3 facet exposure and improved hydrogen binding.

Conclusions:

• The study presents a generalizable route for programmable surface engineering of metal nanoclusters.
• The findings address the paradox between atomic precision and catalytic accessibility in nanocluster catalysis.
• This approach advances the design of highly efficient and stable nanocluster catalysts.