In this research work, Ni-Pd nanoparticles with core-shell structure (CNi-SPd) were synthesized on different catalyst supports such as reduced graphene oxide (rGO), pure polyaniline (PANI) and polymeric composites of rGO with PANI (rGO-PANI) for the first time. In polymeric composite supports, the ratio of rGO to PANI was altered (0.36, 0.14 and 0.11). That way, after chemical reduction of graphene oxide to rGO with sodium borohydride, different polymeric composite supports of rGO-PANI were prepared by chemical oxidation of different amounts of aniline monomer with ammonium persulfate (APS) in rGO dispersions and named as rGO-PANI1 (rGP1), rGO-PANI2 (rGP2) and rGO-PANI3 (rGP3). X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM), fourier transform infrared (FT-IR) spectra, inductively coupled plasma mass spectrometry (ICP-MS) analysis and X-ray photoelectron spectrometer (XPS) were employed to study the morphology and crystal structure of the novel nanostructures. Catalytic behavior of the catalysts respect to NaBH4 oxidation was evaluated in half-cell configuration and in direct borohydride-hydrogen peroxide fuel cell. The cyclic voltammetry results showed that CNi-SPd/rGP1 has the highest borohydride oxidation current density (42678 A. g−1) respect to CNi-SPd/PANI (17072 A. g−1), CNi-SPd/rGO (39085 A. g−1), CNi-SPd/rGP2 (32260 A. g−1) and CNi-SPd/rGP3 (24954 A. g−1). As well as, the single fuel cell studies indicated that with CNi-SPd/rGP1 as anodic electrocatalyst, power density (339.10 mW.cm-2) was enhanced as 64.54% and 8.52% in comparison with CNi-SPd/PANI (120.23 mW.cm-2) and CNi-SPd/rGO (310.20 mW.cm-2), respectively. Theses consequences imply that the rGP1 polymeric composite with the ratio of rGO/PANI = 0.36 is a suitable support substance that can improves the electroactivity for borohydride oxidation considerably.