鑭鈣銅氧相關系列催化劑

Abstract

以檸檬酸鹽法(Amorphous Citrate Precursor，ACP)法及固態燒結法(Solid State Reaction Method)製備出不同之催化劑改變燒結溫度與研磨方式來改善增加比表面積，利用H2O2分解反應測試其催化效能，同時考量比表面積的因素，求出單位比表面積之催化活性，藉以判斷催化劑的催化能力，試驗結果顯示以ACP法在650℃鍛燒0.5小時之La0.6Ca0.4CuO3（A-10-2）催化效能最好。另外並將原有製備氣體擴散電極的製程加以改良，提高催化劑及PTFE在XC-72中的分散性，結果顯示改善後的製程能有效的使PTFE分散在催化劑中，並增加陰極催化層的韌性並能有效的使厚度達均一之效果。 電化學分析，包括定電流放電及極化曲線分析，針對不同之催化劑所製成的氣體擴散電極作測試，由定電流放電曲線中，以ACP法合成之La0.6Ca0.4CoO3(A-2)、La0.6Ca0.4CoO3(A-7)與La0.6Ca0.4CuO3(A-8)的效能最佳。以極化曲線分析各催化劑之氣體擴散電極，結果顯示La0.6Ca0.4CoO3(A-2)、La0.6Ca0.4CoO3(A-7)與La0.6Ca0.4CuO3(A-8)對於氧的還原能力較MnO2高。

In this study, ACP approach and Solid-State Reaction were employed to fabricate perovskite catalysts at various sintering temperatures. In addition, particle reduction methods were used to increase specific surface area (m2/g) for enhanced catalytic performance. H2O2 reduction experiments were performed to evaluate decomposition rate of HO2- by synthesized powders. La0.6Ca0.4CuO3 (A-10-2), produced by ACP method at 650℃ for 0.5hr, exhibited the highest catalytic capability. Further, fabrication process for air electrode was improved to facilitate better dispersion of catalysts and PTFE in carbon substrate. Electrochemical characterizations including galvanostatic and I-V polarization curve were measured. Results of galvanostatic discharge indicated that La0.6Ca0.4CoO3 (A-2), La0.6Ca0.4CoO3(A-7) and La0.6Ca0.4CuO3 (A-8) demonstrate the highest catalytic performance while La0.6Ca0.4CoO3 (A-2), La0.6Ca0.4CoO3 (A-7) and La0.6Ca0.4CuO3 (A-8) still present better ability over that of conventional MnO2.