Selective ring opening of naphthenic molecules in oil upgrading should result in no loss in molecular weight. Benzocyclopentane (indan) ring opening was studied under hydrogen atmospheric pressure at 609 K over poly-(vinylpyrrolidone)-stabilized Ru, Ir and Pd monometallic and Ru–Ir and Ru–Pd bimetallic nanocatalysts prepared by simultaneous reductions. The particle size (mostly within 2 nm) and their monodispersity were confirmed ...