The synthesis and test method of a tri-metal catalyst used for the water electrolyzer and fuel cell

• Main Authors: Hong Syu,Su, 蘇宏旭
• Other Authors: Wei Chin,Chang
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/58227947548083940458

碩士 === 南台科技大學 === 能源工程研究所 === 99 === Proton exchange membrane fuel cells are widely used in electronic communications equipment and vehicles, but the proton exchange membrane fuel cells require high purity hydrogen to work, hydrogen storage methods and safety issue is a problem. Unitized regenerative fuel cell (URFC) is a bi-function device, which is able to produce hydrogen and oxygen as an electrolyzer and work as a fuel cells to produce electricity by consuming hydrogen and oxygen. For the proton exchange membrane fuel cells, this research is potential to eliminate the necessity of supplying hydrogen from external source. To make URFC with both functions of water electrolyzer and fuel cell, the choice of proper catalysts becomes very important. Catalysts with platinum and iridium dioxide supported on titanium nanoparticle by spontaneous deposition method. Using TEM to observe the results of catalyst deposition, and EDX to analyze and prove the ingredients. Measurement of tri-metal catalyst activity is conducted by the cyclic voltammetry with 20 mV/s scanning rate for 90 times. The stability of the catalyst is determined by the change of active area. The results showed adding IPA to catalyst solution produces the best performance. From the observation of TEM, less catalyst agglomeration can be found. The catalyst activity becomes stable and a better performance can be reached through the result observation of cyclic voltammetry method. The impedance spectroscopy analysis showed that adding Ti-black to catalyst will reduce the resistance to 50% (Pt-IrO2 the Rct=4.6 Ωcm2,Pt-IrO2/Ti of Rct=1.9 Ωcm2). It proves that adding Ti-black can increase the conductivity of catalyst, which will be suitable for applying on electrolyzer and fuel cells. Water electrolyzer test results indicate that, when the current density reaches 100mA/cm2, the voltage efficiency of water electrolyzer is about 46% (reaction area 9cm2). Comparing to the referenced work (reaction area 50cm2), the voltage efficiency is about two times higher. Once increases the reaction area, the efficiency of water electrolysis can be enhanced potentially.