B-site錳摻雜鑭鍶層狀鈣鈦礦氧化物觸媒於1 M NaOH水溶液中之氧化還原催化特性研究

Catalytic Activity of LaSr_3Fe_(3-x)Mn_xO_(10) for Oxygen Reduction Reaction in 1 M Sodium Hydroxide Solution

劉富維(F. W. Liu) ； 黃茂嘉(M. C. Huang) ； 黃識軒(S. H. Huang) ； 林景崎(J. C. Lin)

《防蝕工程》 29卷2期 (2015/06) Pp. 73-79

https://doi.org/10.6376/JCCE.201506_29(2).0003

摘要

本研究利用Pechini 法製備B-site 錳摻雜鑭鍶鐵層狀鈣鈦礦氧化物觸媒，以電化學旋轉電極測試分析探討B-site 錳摻雜量對鑭鍶鐵層狀鈣鈦礦氧化物觸媒於1 M NaOH 鹼性溶液中與氧還原(Oxygen reduction reactions, ORR)活性之間的關係。結果顯示Pechini 法製備鑭鍶鐵層狀鈣鈦礦氧化物於1100 °C 退火時間48 小時後為完整結晶，無明顯雜項。B-site錳摻雜量x ＞ 0.5 時會產生四氧化三錳結晶雜相。經由旋轉電極結果顯示，隨著B-site 錳摻雜量增加，氧還原之催化活性亦提升，直至過量錳摻雜導致雜相產生而降低活性。配合Koutecky-Levich equation 計算B-site 錳摻雜有助於催化4 個電子轉移的氧還原反應路徑進而提升氧催化活性。

關鍵字

鈣鈦礦 ； 氧還原反應 ； 旋轉電極 ； Pechini 法

並列摘要

Catalyst activity of LaSr_3Fe_(3-x)Mn_xO_(10) prepared by Pechini method for oxygen reduction reaction (ORR) in 1 M NaOH electrolyte was investigated in this work. The dependence of the catalytic activity was explored by means of rotating disk electrode (RDE). Result from X-ray diffraction revealed that LaSr3Fe3O10 powders synthesized under annealing temperature 1100 °C for 24 hours were pure polycrystalline phase. However, LaSr_3Fe_(3-x)Mn_xO_(10) showed a second phase with doping amount x ＞ 0.5. Analysis of RDE indicated that the catalytic activity of LaSr_3Fe_(3-x)Mn_xO_(10) increased with an increasing x until the appearance of second phase. The electron transfer number was estimated by fitting the RDE data into Koutecky-Levich equation. It was found that Mn substitution with B-site cations make a contribution to catalyze 4-electons transfer reaction, which improved ORR activity.

並列關鍵字

Perovskite ； Oxygen reduction reaction ； Rotating disk electrode ； Pichini method