Influence of the Au/Ag Ratio on the Catalytic Activity of Dendrimer-Encapsulated Bimetallic Nanoparticles in Microreactors

Dendrimer-encapsulated Au/Ag alloy nanoparticles (Au/Ag DENs) were covalently attached to a monolayer-functionalized inner surface of glass microreactors. The influence of the bimetallic alloy structure and of the different metal ratios was investigated for the reduction of 4-nitrophenol using NaBH4. TheAu/Ag-dendrimer nanocomposite with a 1:1 Au/Ag metal ratio showed the highest activity as compared to other metal ratios and to pure Ag and Au. The dendrimer template exerted a stabilizing effect for six consecutive days of use with almost no decrease in conversion. This strategy enables the screening and investigation of a variety of bimetallic nanocatalysts in continuous-flow microreactors.