Preparation and catalytic application of Rh3+/Ru3+ bimetallic catalyst stabilized by triolefinic macrocycle-terminated poly(propylene imine) dendrimer

Abstract

The novel homogeneous bimetallic Rh3+/Ru3+ catalyst (G2-M(Rh3+xRu3+10-x)) was prepared within a second-generation poly(propylene imine) dendrimer terminated by nitrogen-containing triolefinic macrocycle (G2-M) by a co-complexation route. The G2-M(Rh3+x Ru3+10-x) catalyst was analyzed by 1H NMR (nuclear magnetic resonance), XPS (X-ray photoelectron spectroscopy), and XRD (X-ray diffraction). As a novel catalyst system, The bimetallic ions of Rh3+ and Ru3+ influenced on the catalytic activity for the hydrogenation of nitrile-butadiene rubber (NBR), which can be related to electron-deficiency effect resulting from the electron density shift from the Rh3+ to the Ru3+. The G2-M (Rh3+10) and G2-M(Rh3+7Ru3+3) displayed more excellent activity and favorable separation capability for the hydrogenation of NBR than the Rh nanoparticle catalyst stabilized by G2-M (G2-M(Rh10)).