We report a novel alkynyl-protected Ag₂₀Rh₂ bimetallic nanocluster, which possesses unique structure and displays excellent catalytic performance toward hydrogen evolution reaction, 4-nitrophenol reduction, and methyl orange degradation.

Abstract

We report the overall structure and trifunctionality catalytic application of an atomically precise alloy nanocluster of Ag₂₀Rh₂(C≡C-^tBu)₁₆(CF₃CO₂)₆(H₂O)₂ (abbreviated as Ag₂₀Rh₂ hereafter). Ag₂₀Rh₂ has a twisted rod-like structure, where a Ag₄@Rh₂ kernel is connected by two twisted Ag₈ cubes on two sides. Ag₂₀Rh₂ is a superatomic cluster with four free valence electrons, and it has characteristic absorbance feature. Interestingly, Ag₂₀Rh₂ exhibited superior catalytic performance than the larger AgRh nanoparticle counterparts in electrochemical hydrogen evolution reaction (HER), reduction of 4-nitrophenol, and the methyl orange degradation reaction. Such intriguing catalytic properties are attributed to the more exposed active sites from the ultrasmall nanoclusters than relatively large nanoparticles. This study not only enriches the family member of alkynyl-protected AgRh nanoclusters with atomic precision, but also highlights the great advantages of employing nanoclusters as efficient catalysts for multiple functionalities.