A simple design of electroactive and cost-effective electrocatalysts for oxygen reduction reaction (ORR) activity is crucial towards energy conversion in the commercialization of proton exchange membrane fuel cells (PEMFCs). Herein, we synthesized a stable electroactive bimetallic catalyst of Ni anchored with low loading of Pt nanoparticles, and graphene used as a supportive material for catalyst integration (Pt3-Ni/G). It exhibited maximum electrochemical surface area (ECSA, 108.56 m2/gPt), mass activity (2.2 A mgPt) and specific activity (3.47 mA cm-2), signifying an excellent ORR activity. In addition, a scalable PEMFC fabrication through 0.2 mgPtcm-2 Pt3-Ni/G as cathode with an active area of 25 cm2 and stainless steel-314L (SS-314L) used as a serpentine flow field. This strategy provides a maximum power output of 71.25 W mgPt-1 at current density 1.59 A cm-2. In addition, Pt3-Ni/C//Pt/C, based PEMFC system delivered a constant power output (68.75 W mgPt-1) even after 4 h of continuous cycling.