H-2 is generally used as the fuel in proton exchange membrane fuel cells (PEMFCs). However, H-2 produced from reformate gas usually contains a trace of CO, which may severely affect the fuel cell performance. With the adoption of domestic short side chain, low equivalent weight perfluorosulphonic acid (PFSA) membrane, a 100 W stack is built and evaluated at elevated temperature of 95 degrees C for the purpose of improving its CO tolerance. The stack is operated with 5ppm, 10ppm and 20ppm CO/H-2, respectively; better performance is obtained as expected. Furthermore, a 5kW PEMFC stack is prepared with home-made Ir-V/C and Pt/C as anode catalysts for the membrane electrode assemblies to compare their CO tolerance. Physical and electrochemical characterizations, such as transmission electron microscope and linear scan voltammogram are employed for catalyst investigation. The results demonstrate that the employment of domestic PFSA membrane enables the stack to be operated at 95 degrees C, which can improve the CO tolerance of all the anode catalysts. In addition, the effect of CO on cell polarization is insignificant at lower current densities. Under the same operating conditions, cells with Ir-V/C catalyst show better CO tolerance. Copyright (c) 2013 John Wiley & Sons, Ltd.