Ultrafine low loading AgCu nanoclusters supported on defective ZIF-8 for the click reaction with high stability

Abstract

Ultrafine metal nanoclusters have been extensively studied due to their fascinating chemical characteristics. In this work, ultrafine AgCu nanoclusters are synthesized and loaded on the defective ZIF-8 (denoted as AgCu/D-ZIF-8). The findings show that the as-obtained AgCu/D-ZIF-8 catalysts with low AgCu loading (0.387 wt%) exhibit outstanding catalytic performance and recyclability for the reaction of azide–alkyne cycloaddition (click reaction) at 35 °C. Compared with monometallic Ag₂₅/D-ZIF-8 and Cu₂₅/D-ZIF-8 catalysts, bimetallic AgCu/D-ZIF-8 catalysts present exceptional activity for the click reaction. Additionally, AgCu/D-ZIF-8 catalysts display a higher yield of target product for this reaction compared to AgCu/ZIF-8. The experimental results suggest that some defective sites in D-ZIF-8 are occupied by AgCu nanoclusters, which may be key to improving the activity and recyclability of AgCu/D-ZIF-8 catalysts. Consequently, this work provides valuable insights for designing ultrafine bimetallic catalysts with high performance.