Impact of free valence electron contraction on the optical and electrocatalytic properties of nanoclusters: based on M₁Ag₁₄ (M = Pt/Pd) series nanoclusters

Exploring the structure-property relationship of metal nanoclusters is essential, as understanding the underlying mechanisms provides valuable theoretical guidance for designing nanoclusters with enhanced performance. This study investigates Pt₁Ag₁₄(PhS)₆((<i>p</i>-OMePh)₃P)₇ (Pt1Ag14) and Pd₁Ag₁₄(PhS)₆((<i>p</i>-OMePh)₃P)₇ (Pd1Ag14) nanoclusters, focusing on their photoluminescence intensity and electrocatalytic properties. Variations in the core metal atoms lead to significant differences in their characteristics. The Pt1Ag14 nanocluster exhibits a photoluminescence quantum yield of 5.66%, which is substantially higher than the 0.09% observed for Pd1Ag14. In contrast, regarding electrocatalytic performance, Pd1Ag14 demonstrates superior carbon product reduction properties, with a faradaic efficiency of 81.44%, much higher than the 40.82% of Pt1Ag14. Theoretical calculations reveal that while an increase in core valence electron density significantly enhances photoluminescence intensity, it simultaneously reduces the electronegativity of the terminal Ag atom active sites. This reduction raises the energy barrier for the electrochemical CO₂ reduction reaction (eCO₂RR), resulting in a lower yield of carbon-based products. This work provides atomic-level insights into how core atoms influence optical and electrocatalytic properties, revealing their intrinsic connection and offering valuable guidance for designing nanocatalysts with tailored performance.