**4. Conclusion**

Increasing temperature has been proven as an effective way to accelerate fuel cell reactions. To investigate the fuel cell reactions in the intermediate temperature of 80 to 200 °C, we have developed a pressurized electrochemical cell based on a modified commercial Parr autoclave which can be pressurized up to 2000 psi. In this electrochemical cell, aqueous electrolyte solutions and liquid fuels can exist in their liquid forms in the intermediatetemperature range at varying balance pressure. This makes the investigations of intermediate-temperature fuel cell electrocatalysis possible. To further address experimental challenges, we have evaluated three kinds of Ag-based electrodes as an internal reference electrode in basic media and have found that the Ag/AgCl electrode could act as the internal reference electrode with satisfactory stability. To facilitate the investigations of the fuel cell reactions on high-surface-area electrocatalysts, a powder-rubbing procedure has been used to mechanically deposit the electrocatalysts onto a gold substrate of 0.5 mm in diameter. Based upon these efforts, well-developed cyclic voltammograms and chronoamperograms for the electrochemical methanol oxidation and oxygen reduction in the intermediate temperature range have been obtained.

It is encouragingly found that the methanol electrooxidation in alkaline media on highsurface-area Pt and Pd electrodes can be substantially accelerated by increasing temperature, characterized by obvious decrease in the onset overpotential with increasing temperature. Moreover, CO could be oxidized at lower onset potentials than methanol in the intermediate temperature range under similar conditions. This strongly indicates that CO is no longer a poison limiting the methanol oxidation. Replacement of Pt with Pd produces no substantial decrease in the activity towards the methanol oxidation. For the electrochemical oxygen reduction, silver demonstrates a high activity in the intermediate temperature range which is comparable to that of high surface area Pt. This indicates the possibility of using non-Pt catalysts in intermediate-temperature alkaline methanol fuel cells. Our preliminary fuel cell studies demonstrate the high performance of intermediatetemperature alkaline methanol fuel cell with Pt and non-Pt catalysts.
