機械合金法與電化學去合金製程製作複合觸媒應用於燃料電池

Abstract

本實驗以機械合金法製作PtCu合金粉末，再與CeO2均勻混合製成工作電極進行電化學分析，接著再對工作電極進行定電量、定電流去合金處理以獲得高表面積，並測試其陽極甲醇氧化觸媒活性。 結果顯示，以機械合金法製作完成鉑銅粉末已固溶為合金相，為晶粒大小5 ~ 10 nm、平均粒徑1 ~ 3μm之顆粒。去合金處理後之工作電極，經EDX分析發現其組成並無明顯變化，原因推測為去合金期間，電位攀升至1.2~1.5 V導致Pt同時解離。儘管如此，去合金處理後甲醇氧化效能皆有顯著上升，其活性為未去合金處理試片之2.6 ~ 3.5倍。

Pt-Cu powderswere prepared by a mechanical alloying technique, followed by ultrasonically mixing with ceria. Afterward, the powder mixture was coated on a carbon paper to fabricate working electrodes. In addition, the working electrodes underwent a dealloying process to produce a high surface area to study their catalytic abilities for methanol electro-oxidation. Materials characterization on the mechanically alloyed Pt-Cu powders indicated a solid solution, with crystalline size about 5~10 nm and average particle size around 1~3 μm. According to the EDX analysis, the concentration of the solid solution remained unchanged. The phenomenon was probably resulted from the high potential during the dealloying process. The potential rose to 1.2~1.6 V during the dealloying treatment, thus led to considerable Pt dissolution. Nevertheless, the Pt20 samples displayed higher methanol electro-oxidation catalytic activities after dealloying by 2.6 to 3.5 times.