Abstract:

Nano-sized composite proton-conducting membrane of Li₂SO ^4＋Li₂WO ^4＋Al₂O₃was prepared via the sol-gel method,and the electrochemical performance of the fuel cell with the configuration of H₂S,（composite MoS₂ anode catalyst）/composite proton-conducting membrane/（composite NiO cathode catalyst）,air was investigated at various H₂S content,volume flowrate and operation temperature.Moreover,the performances of MoS₂ and composite MoS₂ anode catalysts were analyzed by comparison.Experimental results show that the voltage, output current and power density of the fuel cell all increase with H₂S content and flowrate in the gas mixture due to the improvement of gas diffusion in the anode and due to the increase in the concentration of anodic electroactive species. Thus, the electrochemical performance of the fuel cell becomes better. It is also indicated that, even if the H₂S content is less than 5% （mole fraction）, H₂S can also be used as the fuel for power generation, that not only the electrical conductivity and electrochemical reaction rate of the proton-conducting membrane but also the output current and power density of the fuel cell increase with the temperature, that the composite MoS₂ anode catalyst is superior to the MoS₂ anode catalyst in terms of performance and chemical stability, and that, when pure H₂S with a flowrate of 35 mL/min is input in the anode compartment and the air with a flowrate of 100mL/min is input in the cathode compartment, the fuel cell with composite MoS₂ anode catalyst is of the maximum power densities up to 12.4, 52.9 and 130mW/cm² and the maximum current densities up to 45, 281 and 350mA/cm² respectively at 650, 700 and 750 ℃.

Key words: fuel cell, hydrogen sulfide, proton-conducting membrane, anode catalyst, electrolyte