• alloys;
  • cleavage reactions;
  • iridium;
  • nickel;
  • nanoparticles


A variety of bimetallic Ni–Ir catalysts were synthesised by preforming nanoparticles in the presence of polyvinylpyrrolidone, followed by deposition on γ-alumina and high-temperature polymer removal. The Ni–Ir (1:1 molar ratio) nanoparticles prepared by the hydrogen-sacrificial technique (Ir reduction on the preformed Ni nanoparticles with surface Ni hydride) allowed increasing indane ring opening activity per total amount of Ir as compared to monometallic Ir. The simultaneous reduction of Ni and Ir precursors was not as efficient. The catalysts were characterised with UV/Vis spectroscopy, TEM, temperature-programmed reduction, CO2 temperature-programmed desorption, CO diffuse reflectance Fourier transform spectroscopy, X-ray photoelectron spectroscopy and CHN analysis. The study only explored the catalyst’s metal function and allows saving rare and expensive iridium without loss of its outstanding performance as a ring-opening catalyst.