Design and catalytic application of Ag–Au nanoprisms: enhancing A3 coupling efficiency with minimal gold concentration†

Abstract

A novel bimetallic Ag–Au nanoprism incorporating trace levels of gold (ppm range) was synthesized via a wet-chemical method. The material was comprehensively characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM) mapping, X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). This new nanostructure exhibits a remarkable synergistic interaction between the silver nanoprism and meager amounts of gold, resulting in highly efficient catalytic activity for the A³ coupling reaction involving aldehydes, alkynes, and amines. The reaction proceeds efficiently in water at 60 °C, accommodating a broad substrate scope and showcasing its versatility. Notably, the catalytic system achieves excellent performance even at ultralow gold loadings (80 ppm), highlighting its cost-effectiveness and sustainability. Furthermore, the catalyst demonstrates robust reusability, retaining its activity over four consecutive cycles in aqueous media.