Highly active and durable bifunctional oxygen electrocatalysts have been of pivotal importance for renewable energy conversion and storage devices, such as unitized regenerative fuel cells and metal-air batteries. Perovskite-based oxygen electrocatalysts have emerged as promising nonprecious metal bifunctional electrocatalysts, yet their catalytic activity and stability still remain to be improved. We report a high-performance oxygen electrocatalyst based on a triple perovskite, Nd_1.5Ba_1.5CoFeMnO_9-δ (NBCFM), which shows superior activity and durability for oxygen electrode reactions to single and double perovskites. When hybridized with nitrogen-doped reduced graphene oxide (N-rGO), the resulting NBCFM/N-rGO catalyst shows further boosted bifunctional oxygen electrode activity (0.698 V), which surpasses that of Pt/C (0.801 V) and Ir/C (0.769 V) catalysts and which, among the perovskite-based electrocatalysts, is the best activity reported to date. The superior catalytic performances of NBCFM could be correlated to its oxygen defect-rich structure, lower charge transfer resistance, and smaller hybridization strength between O 2p and Co 3d orbitals.

中文翻译：

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缺氧的三价钙钛矿，是用于氧电极反应的高活性和耐用的双功能电催化剂。

高活性和耐用的双功能氧电催化剂对于可再生能源转换和存储设备（例如，单元式可再生燃料电池和金属空气电池）具有至关重要的意义。钙钛矿基氧电催化剂已经成为有前途的非贵金属双功能电催化剂，但其催化活性和稳定性仍有待提高。我们报告了一种基于三重钙钛矿的高性能氧气电催化剂，Nd _1.5 Ba _1.5 CoFeMnO9 _-δ（NBCFM），它对单和双钙钛矿的氧电极反应显示出优异的活性和耐久性。当与氮掺杂的还原氧化石墨烯（N-rGO）杂交时，所得的NBCFM / N-rGO催化剂显示出更高的双功能氧电极活性（0.698 V），超过了Pt / C（0.801 V）和Ir / C （0.769 V）催化剂，在钙钛矿型电催化剂中，是迄今为止报道的最佳活性。NBCFM的优异催化性能可能与其富氧缺陷的结构，较低的电荷转移阻力以及O 2p和Co 3d轨道之间较小的杂化强度有关。