A Triazole-Based Covalent Gel Loaded with Cu/Pd Bimetallic Nanoparticles for Efficient Catalytic Cross-Coupling Reactions

Metal nanoparticles immobilized in the confined space are a catalogue of efficient and widely used catalysts. Herein we develop a gel-based bimetallic nanoparticle catalytic system with different ratios of Pd/Cu NPs by wet impregnation and reduction using a stable covalent gel (triazole-A1B1) as a porous support. Triazole-A1B1 gel is synthesized from 1,4-diazidobenzene (A1) and tetrakis(4-ethynylphenyl)methane (B1) via Cu(I)-catalyzed azide-alkyne clcloaddition. The bimetallic Pd/Cu metal nanoparticles are highly dispersed and uniformly distributed with an average particle size distribution of 2.06-3.29 nm. Cu/Pd@A1B1 shows high catalytic efficiency in catalyzing Sonogashira-Hagihara and Mizoroki-Heck coupling reactions. The introduction of oxygenophilic Cu effectively improves the catalytic activity of the system. In addition, Cu1Pd2@A1B1 shows good reusability. Especially, it can be reused five times and maintains high catalytic activity without significant deactivation in Mizoroki-Heck coupling reaction.

Automated summary

In this study, a gel-based bimetallic nanoparticle catalytic system with different ratios of Pd/Cu NPs immobilized in a confined space was developed. The system exhibited highly dispersed and uniformly distributed Pd/Cu metal nanoparticles with an average particle size distribution of 2.06-3.29 nm. It showed high catalytic efficiency in Sonogashira-Hagihara and Mizoroki-Heck coupling reactions, and the introduction of oxygenophilic Cu effectively improved the catalytic activity. Furthermore, the Cu1Pd2@A1B1 catalyst demonstrated good reusability, maintaining high catalytic activity for up to five cycles in Mizoroki-Heck coupling reaction without significant deactivation.