Sunday, 13 October 2019: 16:50
Room 222 (The Hilton Atlanta)
Epitaxy of complex perovskite oxides has arrived at atomic scale precision. This opens new chances and opportunities to the field of electrolysis and water splitting, where perovskite oxides show
promising catalytic activity for the oxygen evolution reaction (OER). While representing ideal model systems for improving our scientific understanding of atomistic processes and scaling relations during OER, epitaxial heterostructures furthermore give access to atomic band engineering strategies and allow the generation of hybrid materials, which may combine beneficial properties of neighboring materials on the nanoscale. These strategies render novel opportunities to enhance chemical stability and to tune overpotentials of OER-active perovskite materials, not accessible in the bulk. Epitaxial catalysts can therefore play an important role in achieving new breakthroughs and guide lines in the field. Here, we discuss synthesis, electronic transport and electrochemical performance of atomically engineered cobaltite thin films. The epitaxial character of the OER catalysts allows to probe parameters such as electronic transport, evolution of crystal structure, over-potential and lifetime, in well-defined sample geometries and in absence of chemical admixture of binders or current collecting materials. As we reveal, single-crystalline epitaxial catalysts can show perfomance well-comparable to powder catalysts whilst revealing (100) crystallographic facets highly favored for oxygen evolution.
promising catalytic activity for the oxygen evolution reaction (OER). While representing ideal model systems for improving our scientific understanding of atomistic processes and scaling relations during OER, epitaxial heterostructures furthermore give access to atomic band engineering strategies and allow the generation of hybrid materials, which may combine beneficial properties of neighboring materials on the nanoscale. These strategies render novel opportunities to enhance chemical stability and to tune overpotentials of OER-active perovskite materials, not accessible in the bulk. Epitaxial catalysts can therefore play an important role in achieving new breakthroughs and guide lines in the field. Here, we discuss synthesis, electronic transport and electrochemical performance of atomically engineered cobaltite thin films. The epitaxial character of the OER catalysts allows to probe parameters such as electronic transport, evolution of crystal structure, over-potential and lifetime, in well-defined sample geometries and in absence of chemical admixture of binders or current collecting materials. As we reveal, single-crystalline epitaxial catalysts can show perfomance well-comparable to powder catalysts whilst revealing (100) crystallographic facets highly favored for oxygen evolution.
References
Weber & Gunkel, Epitaxial catalysts for oxygen evolution reaction: model systems and beyond, JPhys. Energy just accepted manuscript (2019)
Weber et al., Electrolysis of Water at Atmoically tailored Epitaxial Cobaltite Surfaces, Chemistry of Materials, 31(7), 2337 - 2346 (2019)
Gunkel et al., Ordering and phase control in epitaxial (Pr,Ba)CoO3-δ catalysts for oxygen evolution reaction, ACS Catalysis 8, 7029 (2017)