Tuning Bifunctional Oxygen Electrocatalysts by Changing the A-Site Rare-Earth Element in Perovskite Nickelates
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Nanyang Technological Univ. (Singapore)
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Nanyang Technological Univ. (Singapore)
- Chinese Academy of Sciences (CAS), Beijing (China). Inst. of High Energy Physics
- National Univ. of Singapore (Singapore)
- Zhengzhou Univ. (China)
Perovskite-structured (ABO3) transition metal oxides are promising bifunctional electrocatalysts for efficient oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). In this paper, we investigate a set of epitaxial rare earth nickelates (RNiO3) thin films with controlled A-site isovalent substitution to correlate their structure and physical properties with ORR/OER activities. The ORR activity is shown to decrease monotonically with decreasing the A-site element ionic radius which lowers the conductivity of the RNiO3 (R = La, La0.5Nd0.5, La0.2Nd0.8, Nd, Nd0.5Sm0.5, Sm, Gd) films, with LaNiO3 being the most conductive and active. On the other hand, the OER activity initially increases upon substituting La with Nd and is maximal at La0.2Nd0.8NiO3, in which oxygen vacancies (VOs) start to form. Moreover, the OER activity remains comparable within error through Sm-doped NdNiO3. Beyond that, we cannot reliably measure activity due to the potential voltage drop across the film. The improved OER activity is ascribed to the partial reduction of Ni3+ to Ni2+ as a result of VOs, which increases the average occupancy of the eg antibonding orbital to more than one. Our work highlights the importance of tuning A-site elements as an effective strategy for balancing the ORR and OER activities of bifunctional electrocatalysts.
- Research Organization:
- Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Biological and Environmental Research (BER)
- Grant/Contract Number:
- AC05-76RL01830; 68278
- OSTI ID:
- 1647169
- Alternate ID(s):
- OSTI ID: 1463195
- Report Number(s):
- PNNL-SA-135288
- Journal Information:
- Advanced Functional Materials, Vol. 28, Issue 39; ISSN 1616-301X
- Publisher:
- WileyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Enhanced Electrocatalytic Oxygen Evolution Activity by Tuning Both the Oxygen Vacancy and Orbital Occupancy of B‐Site Metal Cation in NdNiO 3
|
journal | June 2019 |
Tuning the Electronic Structure of LaNiO 3 through Alloying with Strontium to Enhance Oxygen Evolution Activity
|
journal | August 2019 |
Recent Studies on Bifunctional Perovskite Electrocatalysts in Oxygen Evolution, Oxygen Reduction, and Hydrogen Evolution Reactions under Alkaline Electrolyte
|
journal | May 2019 |
Screening highly active perovskites for hydrogen-evolving reaction via unifying ionic electronegativity descriptor
|
journal | August 2019 |
Similar Records
Stable, high-performing bifunctional electrodes for anion exchange membrane-based unitized regenerative fuel cells
Theoretical investigation of superconductivity in trilayer square-planar nickelates