Different generations of poly(propylene imine) (Gn-PPI) terminated with N-containing 15-membered triolefinic macrocycle (GnM) (n = 2, 3, 4, 5) had been prepared. The bimetallic nanoparticles catalysts GnM-(Ptx/Pd10-x) (x = 0, 3, 5, 7, 10) were prepared by synchronous ligand-exchange reaction between GnM and the complexes of Pt(PPh3)4 and Pd(PPh3)4. The structure and catalytic propreties of GnM-(Ptx/Pd10-x) were characterized via FTIR, 1H NMR, XRD, XPS, HRTEM, and EDS. The novel bimetallic Pd-Pt nanoparticles catalysts stabilized by dendrimers (DSNs) present higher catalytic activities for the hydrogenation of dimeric acid (DA) than that of nitrile butadiene-rubber (NBR), it can be concluded that bimetallic Pd-Pt DSNs possess alloying and synergistic electronic effects on account of the hydrogenation degree (HD) of DA and NBR. Furthermore HD of DA and NBR show a remarkable decrease with the incremental generations (n) of GnM-(Pt3/Pd7) (n = 2, 3, 4, 5).