TY - JOUR
T1 - Activity-Stability Relationships in Oxide Electrocatalysts for Water Electrolysis
AU - Wohlgemuth, Marcus
AU - Weber, Moritz L.
AU - Heymann, Lisa
AU - Baeumer, Christoph
AU - Gunkel, Felix
N1 - Funding Information:
FG acknowledges funding by the German Research Foundation in the framework of the SPP 2080, project no 493705276 (GU1604/4). MaW, FG thank the FLAG-ERA “To2Dox” (DFG project no 436610738 /DI 919/8-1). Support from the University of Twente in the framework of the tenure track start-up package is gratefully acknowledged.
Funding Information:
FG acknowledges funding by the German Research Foundation in the framework of the SPP 2080, project no 493705276 (GU1604/4). MaW, FG thank the FLAG-ERA “To2Dox” (DFG project no 436610738 /DI 919/8-1). Support from the University of Twente in the framework of the tenure track start-up package is gratefully acknowledged.
Publisher Copyright:
Copyright © 2022 Wohlgemuth, Weber, Heymann, Baeumer and Gunkel.
PY - 2022/6/23
Y1 - 2022/6/23
N2 - The oxygen evolution reaction (OER) is one of the key kinetically limiting half reactions in electrochemical energy conversion. Model epitaxial catalysts have emerged as a platform to identify structure-function-relationships at the atomic level, a prerequisite to establish advanced catalyst design rules. Previous work identified an inverse relationship between activity and the stability of noble metal and oxide OER catalysts in both acidic and alkaline environments: The most active catalysts for the anodic OER are chemically unstable under reaction conditions leading to fast catalyst dissolution or amorphization, while the most stable catalysts lack sufficient activity. In this perspective, we discuss the role that epitaxial catalysts play in identifying this activity-stability-dilemma and introduce examples of how they can help overcome it. After a brief review of previously observed activity-stability-relationships, we will investigate the dependence of both activity and stability as a function of crystal facet. Our experiments reveal that the inverse relationship is not universal and does not hold for all perovskite oxides in the same manner. In fact, we find that facet-controlled epitaxial La0.6Sr0.4CoO3-δ catalysts follow the inverse relationship, while for LaNiO3-δ, the (111) facet is both the most active and the most stable. In addition, we show that both activity and stability can be enhanced simultaneously by moving from La-rich to Ni-rich termination layers. These examples show that the previously observed inverse activity-stability-relationship can be overcome for select materials and through careful control of the atomic arrangement at the solid-liquid interface. This realization re-opens the search for active and stable catalysts for water electrolysis that are made from earth-abundant elements. At the same time, these results showcase that additional stabilization via material design strategies will be required to induce a general departure from inverse stability-activity relationships among the transition metal oxide catalysts to ultimately grant access to the full range of available oxides for OER catalysis.
AB - The oxygen evolution reaction (OER) is one of the key kinetically limiting half reactions in electrochemical energy conversion. Model epitaxial catalysts have emerged as a platform to identify structure-function-relationships at the atomic level, a prerequisite to establish advanced catalyst design rules. Previous work identified an inverse relationship between activity and the stability of noble metal and oxide OER catalysts in both acidic and alkaline environments: The most active catalysts for the anodic OER are chemically unstable under reaction conditions leading to fast catalyst dissolution or amorphization, while the most stable catalysts lack sufficient activity. In this perspective, we discuss the role that epitaxial catalysts play in identifying this activity-stability-dilemma and introduce examples of how they can help overcome it. After a brief review of previously observed activity-stability-relationships, we will investigate the dependence of both activity and stability as a function of crystal facet. Our experiments reveal that the inverse relationship is not universal and does not hold for all perovskite oxides in the same manner. In fact, we find that facet-controlled epitaxial La0.6Sr0.4CoO3-δ catalysts follow the inverse relationship, while for LaNiO3-δ, the (111) facet is both the most active and the most stable. In addition, we show that both activity and stability can be enhanced simultaneously by moving from La-rich to Ni-rich termination layers. These examples show that the previously observed inverse activity-stability-relationship can be overcome for select materials and through careful control of the atomic arrangement at the solid-liquid interface. This realization re-opens the search for active and stable catalysts for water electrolysis that are made from earth-abundant elements. At the same time, these results showcase that additional stabilization via material design strategies will be required to induce a general departure from inverse stability-activity relationships among the transition metal oxide catalysts to ultimately grant access to the full range of available oxides for OER catalysis.
KW - activity-stability relations
KW - green hydrogen
KW - oxide electrocatalysis
KW - oxygen evolution reaction
KW - perovskite—type oxide
KW - water electrolysis
UR - https://www.scopus.com/pages/publications/85133886659
U2 - 10.3389/fchem.2022.913419
DO - 10.3389/fchem.2022.913419
M3 - Article
AN - SCOPUS:85133886659
SN - 2296-2646
VL - 10
JO - Frontiers in Chemistry
JF - Frontiers in Chemistry
M1 - 913419
ER -