Improvement in electrochemical properties of platinum (Pt)-based bimetallic electrocatalyst is one of the challenges towards efficient proton exchange membrane fuel cell (PEMFC). Performance of bimetallic nanoparticles is expected to match with Pt electrocatalyst. To address this challenge, we synthesized nanosized platinum-molybdenum/carbon (Pt-Mo/C) catalyst in a continuous flow milli-channel reactor and used it in PEMFC. Further, we studied the influence of loading on particle size and distribution of the catalyst. The particle size of less than 5 nm was obtained for 20 wt% loading of Pt-Mo/C. Electrochemical properties of the catalyst were investigated using cyclic voltammetry (CV) and linear sweep voltammetry (LSV). The data were further processed to obtain an electrochemical surface area (ECSA) and open circuit voltage (OCP) of the fuel cell. The specific activity and mass activity of Pt-Mo/C were 24.4 mA/cm2 and 48.8 mA/mg, respectively for 40 wt% loading. Bimetallic nanoparticles utilizing less amount of Pt is expected to reduce the use of noble metals in PEMFC enabling the commercial feasibility of this cleaner source of energy.