新型La0.6Ca0.4CoxIryRu1-x-yO3 鈣鈦礦催化劑在雙效性燃料電池之應用

Abstract

面對全球能源危機，是現今迫切需要解決的問題，因此，開發高效率低 污染的新綠色能源，是刻不容緩的事。其中燃料電池相關的研究一日千里， 因而對於新穎材料開發、研究及功性能之技術便益顯重要。 鹼性系統燃料電池由於結構簡單、高能量密度、性能穩定及對環境影響 較低等優點，在近期頗受重視。本實驗室近年在鈣鈦礦氧化物La0.6Ca0.4CoO3 觸媒中成功地摻雜Ir4+，成功合成出La0.6Ca0.4CoIr0.25O3.5 觸媒，此外，更令 人振奮的是鹼性系統下La0.6Ca0.4CoIr0.25O3.5 觸媒的電化學活性，相對於商業 上已被廣泛使用的 La0.6Ca0.4CoO3 觸媒，不論是放電或充電，皆能有效地降 低電流對電壓的損失而有效地提升電化學性能。因此，本研究延續此一系 統，嘗試以ACP 法和固態燒結法合成不同Ru4+及Ir4+摻雜量之鈣鈦礦氧化 物(La0.6Ca0.4CoxIryRu1-x-yO3)，對電化學氧生成還原之雙效活性做更深入的的 探討。

Alkaline fuel cells are unique electrochemical energy generation systems that are expected to become the dominant power devices in the near future. To date, considerable interests have concentrated on the alkaline systems for its usage of non-platinum based electrocatalysts which promises immediate commercial viability. The critical challenge for a practical device is the identification of efficient electrocatalysts for the oxygen reduction at cathode. Current activities in our laboratory have successfully synthesized metastable La0.6Ca0.4CoIr0.25O3.5 by mechanical alloying of La0.6Ca0.4CoO3 and IrO2, and observed significant bifunctional catalytic abilities for the oxygen reduction. This newly developed material therefore exhibits substantial potential as the cathode electrocatalyst for rechargeable fuel cells in which facile oxygen reduction and evolution are required. Results in electrochemical analysis confirmed its superiority over the conventional material of La0.6Ca0.4CoO3. This proposal covers a one year period to synthesize stoichiometric La0.6Ca0.4CoxIryRu1-x-yO3 at various compositions by methods of ACP and solid state reaction. We intend to conduct detailed material characterizations as well as electrochemical analysis to identify the exact perovskite composition with the highest bifunctional catalytic abilities.