The composition and atomic structure of nanoalloy catalysts in the Ethanol Oxidation Reaction (EOR) play an important role. To study this and develop an electrochemically active catalyst towards ethanol electro-oxidation, a second oxophilic metal has generally been initiated as an alloy, capable of enhancing the electrocatalytic activity of Platinum. In view of the above, the present investigation deals with nano particles of PtRu with different bimetallic compositions supported on Multiwalled Carbon Nano Tube (MWCNT) for their activity on the Ethanol electro-oxidation. The structure, morphology and bonding of the catalysts were studied by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy-Dispersive X-Ray Fluorescence (EDXRF) and Fourier-Transform Infrared spectroscopy (FTIR). Electrochemical methods like Cyclic Voltammetry (CV), Linear Sweep Voltammetry (LSV) and Chronoamperometry (CA) were used to explore the catalytic activity towards Ethanol electro-oxidation. This study focused on establishing the relationship between the catalysts’ composition, atomic structure and catalytic activity for the EOR. All the results of physical and electrochemical studies revealed an intriguing composition-structure-activity relationship for the PtRu electrocatalysts under EOR experimental conditions. In particular, the alloy with a Pt/Ru ratio of ∼84:16 was found to exhibit a maximum EOR activity as a function of the bimetallic composition. Notably, the catalytic activities of the C/PtRu electrocatalysts showed a significant improvement during the EOR. The results show some new light on the composition of C/PtRu catalysts regarding ethanol oxidation reaction which is important for the rational design and synthesis of active nanoalloy catalysts for Direct Ethanol Fuel Cell (DEFC).