Description:
Oxygen evolution reaction (OER) is a necessary reaction for several promising energy storage and conversion technologies such as metal-air batteries, reversible fuel cells, water splitting for hydrogen production, and carbon dioxide reduction. Since the kinetics of the four-electron transfer process is notoriously sluggish, the development of highly efficient OER electrocatalysts is urgently needed. In this presentation, we will report our recent progress in design, synthesis, and characterization of perovskite oxides as highly efficient and robust electrocatalysts for OER, including double perovskite PrBa0.5Sr0.5Co1.5Fe0.5O5+ δ (PBSCF),[1] single perovskite La0.6Sr0.4Co1–xFexO3–δ [2] nanofibers, and surface-modified perovskite nanofibers. The remarkable electrocatalytic activity of PBSCF with A/B site co-doping is attributed to the Fe site, as rationalized by theoretical computations and confirmed by experimental measurements. Further, the nanofibers of these materials (with a diameter of ~20 nm) demonstrate a significant enhancement in intrinsic activity while maintaining excellent durability, achieving performance superior to those of the commercial IrO2 catalyst. Moreover, a unique surface-modification strategy has been developed recently, resulting in more than two orders of magnitude enhancement in intrinsic activity of PBSCF nanofibers, which is more than three orders of magnitude higher than that of IrO2. [1] Zhao, B. T., Zhang, L., Zhen, D. X., Yoo, S., Ding, Y., Chen, D. C., Chen, Y., Zhang, Q. B., Doyle, B., Xiong, X. H., Liu, M. L. A tailored double perovskite nanofiber catalyst enables ultrafast oxygen evolution. Nat. Commun. 8, 14586 (2017). [2] Zhen, D. X., Zhao, B. T., Shin, H. C., Bu, Y. F., Ding, Y., He, G. H., Liu, M. L. Electrospun porous perovskite La0.6Sr0.4Co1–xFexO3–δ nanofibers for efficient oxygen evolution reaction, Adv. Mater. Interfaces 4, 1700146 (2017).