十二面体
材料科学
纳米棒
金属有机骨架
血红素
金属
纳米颗粒
沸石咪唑盐骨架
氧化还原
纳米技术
化学工程
结晶学
化学
冶金
血红素
有机化学
酶
吸附
工程类
作者
Chenxi Qiu,Rui Gao,Yizheng Guo,Jiaqi Qin,Guanghui Zhang,Yujiang Song
标识
DOI:10.1002/admi.202200852
摘要
Abstract The durability improvement of Fe‐N‐C electrocatalysts toward acidic oxygen reduction reaction (ORR) remains a grand challenge. H 2 O 2 seriously degrades Fe‐N‐C sites, which account for a major origin of the low durability. Herein, the growth of hemin decorated zeolitic imidazole framework (hemin‐ZIF 8) on preformed Ce‐1,3,5‐benzenecarboxylic acid (Ce‐BTC) metal organic frameworks (MOFs) is reported. Interestingly, the resultant dual MOFs appear to be Ce‐BTC nanorods decorated with many hemin‐ZIF 8 dodecahedral nanocrystals, well resembling rice panicles. After pyrolysis, CeO 2 nanoparticles are evenly distributed in carbonized nanorods and abundant Fe‐N‐C sites are embedded in shrunk dodecahedra, labeled as Fe‐N‐C‐CeO 2 . Fe‐N‐C‐CeO 2 exhibits a high ORR activity in terms of a half wave potential (E 1/2 ) of 0.800 V (vs RHE). The high ORR activity is closely correlated with the well exposure of Fe‐N‐C sites. In addition, the presence of CeO 2 leads to a low H 2 O 2 yield of Fe‐N‐C‐CeO 2 (2.3%), much lower than that of Fe‐N‐C (4.3%) by itself in the absence of CeO 2 . After 5000 potential cycling, the E 1/2 of Fe‐N‐C‐CeO 2 degrades 15 mV superior to that of Fe‐N‐C (42 mV). Moreover, a single cell with Fe‐N‐C‐CeO 2 as cathode degrades much slower than that of Fe‐N‐C (28 000 s vs 7200 s) during chronoamperometric measurements.
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