Self-assembled three-dimensional Pd/MoS2/reduced graphene oxide nanocatalyst: A case for homogeneous leaching mechanism

In this work, a new design of three-dimensional (3D) molybdenum disulfide-reduced graphene oxide nanosheets supported palladium (Pd/MoS2-rGO) catalyst was prepared by a facile one-pot self assembled procedure. The existence of MoS2 not only succeeded in preventing the restacking of rGO nanosheets and increasing the specific surface area, but also afforded an additional transport platform for Pd nanoparticles to facilitate its catalytic properties. Because of the specific structural and different functional components, the as-prepared Pd/MoS2-rGO showed superior catalytic performance and reusability towards the cross-coupling reactions and the reduction of 4-nitrophenol. Moreover, it was confirmed that the catalytic nature of Pd catalyst is a kind of similar homogeneous leaching mechanism with the hot filtration test, the solid-phase poisoning and the three-phase test,etc. This means that leaching of soluble Pd species promotes the reaction process in the liquid phase, and the leaching Pd can return to the carrier of catalyst after completion of transformation. Therefore, the rational design of 3D MoS2-rGO hydrogel material supported highly active Pd nanoparticles, combined with a facile one-pot self-assembled procedure, provides a universal strategy to construct desirable 3D multifunctional nanocatalysts that can be used to research the catalytic nature of active Pd. (C) 2017 Elsevier Inc. All rights reserved.