Wednesday, April 26, 2023
15:40 - 16:45
Earth-abundant, active, selective and stable electrocatalysts are the cornerstone in our transition to defossilisation of the chemical industry, sector coupling, and sustainable energy, because they enable, for example, generation of green hydrogen through water electrolysis. Traditional electrocatalyst materials design relies on tuning the electronic and atomic structure of the as-prepared electrocatalyst through compositional variations . But the catalyst surface is known to transform at the interface to the electrolyte, especially under operation conditions. Only the properties of the transformed interface coupled to the underlying layer gives rise to observed metrics like activity and stability. In this talk I will highlight recent developments in the catalyst design for perovskite oxide electrocatalysts and introduce the growing understanding of surface transformations during the reaction. I will discuss examples from LaNiO3 model systems, where the surface transformation on Ni-terminated (001)-facets results in dramatic activity improvement compared to the La-terminated (001)-facets . Then I will introduce a multi-cation perovskites (so-called high entropy oxides, HEO), as a novel electrocatalyst material, where X-ray photoelectron spectroscopy reveals a synergistic effect of simultaneous oxidation and reduction of different transition metal cations during adsorption of reaction intermediates .
1. Yamada, I. et al. Systematic Study of Descriptors for Oxygen Evolution Reaction Catalysis in Perovskite Oxides. The Journal of Physical Chemistry C 122, 27885–27892 (2018).
2. Baeumer, C. et al. Tuning electrochemically driven surface transformation in atomically flat LaNiO3 thin films for enhanced water electrolysis. Nat Mater 20, 674–682 (2021).
3. Kante, M. V et al. A High-Entropy Oxide as High-Activity Electrocatalyst for Water Oxidation. ACS Nano 17, 5329–5339 (2023).
UvA - Faculty of Science
hard condensed matter, quantum matter