Stabilized catalyst comprising nickel and supported 12-tungstophosphoric acid: synthesis, characterization and aqueous-phase Suzuki-Miyaura cross-coupling

This work describes a simple impregnation and soaking method for designing of stabilized nickel exchanged supported 12-tungstophosphoric acid, its characterization and use as a heterogeneous catalyst for carrying out Suzuki-Miyaura (SM) cross-coupling in aqueous medium. The influence of various reaction parameters was screened for maximum conversion, and the catalyst was found to exhibit an excellent activity (89% conversion) with a very small amount of active species (0.26 mol% of Ni) under mild conditions. The catalyst was retrieved by centrifugation, reactivated by heating at 100 degrees C only and reused without exhibiting any significant change in conversion up to three catalytic runs. The stability of the regenerated catalyst was confirmed by FT-IR, XPS and TEM analysis.