Copper and palladium bimetallic sub-nanoparticles were stabilized on modified polyaniline materials as an efficient catalyst to promote C-C coupling reactions in aqueous solution

Modified polyaniline self-stabilizing Cu/Pd bimetallic sub-nanocluster composite materials (Cu/Pd@Mod-PANI-3OH) are obtained through the three steps of oxidative polymerization, structural modification, and metal self-trapping. Palladium and copper are confined and coordinated in the composite material by participating in the reaction and are highly uniformly dispersed in the carrier in the form of sub-nano clusters. The Cu/Pd@Mod-PANI-3OH micro-nano reactor catalyst formed by the self-assembly of copper, palladium and polyaniline has excellent electronic effects, including a tunable microenvironment, metal-carrier and metal-metal synergy, and the stabilizing effect of metal by polyaniline materials. It can efficiently catalyse C-C coupling (Sonogashira and Suzuki) reactions in aqueous solution with high catalytic activity and a wide range of applications (40 substrates). The characterization test results show that the Cu/Pd@Mod-PANI-3OH composite material obtained by self-trapping metal is a kind of prefabricated catalyst. During the reaction process, the high-valent metals in the pre-catalyst are in situ converted into active zero-valent metals. The catalyst's pre-fabrication strategy well protects the catalytic active centre, largely prevents agglomeration of the metal particles (can be recycled 8 times) and exhibits excellent interfacial domain-limited catalysis. The research strategy of modulation of catalytic active sites to improve the properties of materials at the molecular and atomic level reported in this article will open a new door in the research of polyaniline materials.

Automated summary

Modified polyaniline self-stabilizing Cu/Pd bimetallic sub-nanocluster composite materials obtained through oxidative polymerization, structural modification, and metal self-trapping show excellent catalytic performance.