為減少高溫質子交換膜燃料電池（HT-PEMFC）觸媒層中貴金屬的擔載量，本研究採用脈衝雷射沉積(PLD)在氣體擴散層表面製備納米顆粒堆疊多孔觸媒層。並將聚苯並咪唑滴塗在觸媒層上作為介面層，形成電極。並通過熱壓將電極夾在吸附磷酸的商用聚苯並咪唑（PBI）質子交換膜的兩側，形成膜電極組（MEA）。脈衝雷射沉積製備的奈米顆粒堆疊觸媒層具有良好的電子傳輸路徑，可以提高觸媒的利用率，減少鉑的用量。採用滴塗法在觸媒層上形成PBI膜，可以改善觸媒層與質子交換膜的接觸，同時增加電化學反應的三相界面。本論文首先對商用PBI膜的磷酸摻雜參數進行了優化，以避免過度吸附磷酸，避免其滲入觸媒層造成酸淹現象，並具合適的質子傳導率和機械強度。由於HT-PEMFC的工作溫度高於水的沸點，質子在觸媒層中的傳輸依賴於磷酸間和水分子之間的跳躍機制。在催化劑層上直接滴塗PBI薄膜可以提供固定的磷酸吸附位點，形成質子通道。與優化後的滴塗聚苯並咪唑膜在其厚度為50 nm時和未滴塗PBI膜的電池相比，在160 oC和0.6 V的測試條件下，燃料電池電流密度可提高105.3%。;In order to reduce the precious metals loading in the catalyst layer of high-temperature proton exchange membrane fuel cells (HT-PEMFC), this study uses pulsed laser deposition to prepare nanoparticle stacked porous catalyst layer on the surface of the gas diffusion layer. And the polybenzimidazole was drop-casted on the catalyst layer as the interface layer to form an electrode. And then, electrodes were sandwiched on both sides of the phosphoric acid imbibed commercial polybenzimidazole (PBI) proton exchange membrane by hot-pressing to form a membrane electrode assembly (MEA). The nanoparticle stacked catalyst layer prepared by pulsed laser deposition has good electron transporting path, which can improve the utilization of the catalyst and reduce the amount of platinum. Using the drop-coating method to form a film on the catalyst layer can improve the contact between the catalyst layer and the proton exchange membrane and, at the same time, increase the three-phase interface of the electrochemical reaction. This thesis first optimized the phosphoric acid embedding parameters of commercial PBI membranes to avoid acid flooding caused by the infiltration of excessively adsorbed phosphoric acid through the catalyst layer and to have suitable proton conductivity and mechanical strength. Since the operating temperature of the HT-PEMFC is higher than the boiling point of water, the proton transporting in catalyst layer relies on hopping mechanism between phosphoric acid and water molecules. Direct drop-casting of PBI film on the catalyst layer can provide fixed phosphoric acid adsorption sites to form proton channels. Comparing the optimized drop-coated polybenzimidazole membrane on catalyst layer of a thickness of 50 nm and without casting PBI membrane, the fuel cell current density can be increased by 105.3% with test conditions of 160 oC and 0.6 V.
