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Title: Understanding Structure–Activity Relationships in Sr1–xYxCoO3–δ through in Situ Neutron Diffraction and Electrochemical Measurements

Journal Article · · ACS Applied Materials and Interfaces

In this study, we report a systematic study on temperature-dependent local structural evolution, oxygen stoichiometry, and electrochemical properties of an oxygen-deficient perovskite Sr0.7Y0.3CoO3–δ (SYC30) for oxygen electrocatalysis. The obtained results are then closely compared with its analogue Sr0.9Y0.1CoO3–δ (SYC10) of different crystal structures to establish structure–activity relationships. The comparison shows that both SYC30 and SYC10 consist of alternate layers of oxygen-deficient Co1-polyhedra and oxygen-saturated Co2-octahedra with Co1-polyhedra being responsible for Vo•• migration. It is also found that the distribution and concentration of oxygen vacancies within the Co1-layer are, respectively, less symmetrical and lower in SYC30 than those in SYC10, making the former unfavorable for oxygen transport. A molecular orbital energy analysis reveals that the energy gap between Fermi level and O 2p level in the active Co1-polyhedra is larger in SYC30 than that in SYC10, further suggesting that SYC10 is a better oxide-ion conductor and thus a better electrocatalyst for oxygen reduction reaction, which is unambiguously confirmed by the subsequent electrochemical measurements.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Advanced Research Projects Agency - Energy (ARPA-E); USDOE Office of Fossil Energy (FE)
Grant/Contract Number:
AC05-00OR22725
OSTI ID:
1483181
Journal Information:
ACS Applied Materials and Interfaces, Vol. 10, Issue 42; ISSN 1944-8244
Publisher:
American Chemical Society (ACS)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 4 works
Citation information provided by
Web of Science

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Cited By (1)


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