A novel Pd-Ni bimetallic synergistic catalyst on ZIF-8 for Sonogashira coupling reaction

Monometallic Pd@ZIF-8, Ni@ZIF-8 and bimetallic PdxNiy@ZIF-8 catalysts have been successfully synthesized by a simple liquid impregnation-reduction method. The structure of catalysts and the electronic states of introduced metals were characterized and their catalytic performances were evaluated in Cu free and ligands free Sonogashira coupling reaction under atmosphere. Compared with monometallic catalyst, the as-synthesized bimetallic Pd5Ni95@ZIF-8 catalyst exhibited excellent catalytic performance with 94.50% yield. Therefore, the above experimental results suggested a synergistic effect derived from palladium and nickel, which enhanced Sonogashira coupling reaction obviously. Moreover, modification of Ni@ZIF-8 with trace of palladium can effectively promote its catalytic activity, indicating an economical way to develop efficient catalysts. (C) 2018 Elsevier B.V. All rights reserved.