▎ 摘　　要

The higher methanol utilization efficiency in direct methanol fuel cell (DMFC) is one of the key parameter to show the performance of an anode catalyst. Here in, we have synthesized a highly efficient and stable PtCo anode nanocatalysts (2-4 nm size) supported on reduced graphene oxide (rGO) for the electro-oxidation of methanol in a DMFC. Three different compositions of anode catalysts PtCo (1:7)/rGO, PtCo (1:9)/rGO and PtCo (1:11)/rGO comprising of 20% metal loading by weight of rGO are being investigated for methanol electro-oxidation in acidic medium with different methanol concentration using cyclic voltammetry. The electrochemical response from three different catalysts revealed that the PtCo (1:9)/rGO catalyst has efficiently oxidized 5 M methanol in a half cell configuration. A peak anodic current density of 46.8 mA/cm(2) and a power density of 136.8 mW/cm(2) are achieved using PtCo (1:9)/rGO anode catalyst at 100 degrees C for DMFC with 5 M methanol supply with negligible amount of methanol crossover. About 34% Faradaic efficiency and 22% energy efficiency is attained using PtCo (1:9)/rGO anode catalyst for a DMFC. Further, the 3% methanol oxidation reaction (MOR) efficiency is attained as revealed by evaluating the MOR by-products i.e., formic acid and formaldehyde formation. The results indicate excellent catalytic behavior of PtCo (1:9)/rGO towards MOR and its potential application as anode catalyst in DMFC.