Prof. Dr. Robert Schlögl
Academic Research Focus
- Sustainable Energy Conversion Processes
Fields of Application
Fuel Cells, Hydrogen, Photo-(electro)catalysis, Solar Fuels
Publications
10.
K Dembélé, J H Wang, M Boniface, J Folke, L S Diaz, F Girgsdies, A Hammud, D Kordus, G Koch, Z Gheisari, R Blume, W L Y Jiang, A Knop-Gericke, R Eckert, S Reitmeier, A Reitzmann, R Schlögl, B R Cuenya, J Timoshenko, H Ruland, T Lunkenbein
The Haber Bosch Catalyst from Solid state Chemistry to Mesotechnology Journal Article
In: Advanced Energy Materials, 2025, ISSN: 1614-6832.
@article{nokey,
title = {The Haber Bosch Catalyst from Solid state Chemistry to Mesotechnology},
author = {K Demb\'{e}l\'{e} and J H Wang and M Boniface and J Folke and L S Diaz and F Girgsdies and A Hammud and D Kordus and G Koch and Z Gheisari and R Blume and W L Y Jiang and A Knop-Gericke and R Eckert and S Reitmeier and A Reitzmann and R Schl\"{o}gl and B R Cuenya and J Timoshenko and H Ruland and T Lunkenbein},
url = {\<Go to ISI\>://WOS:001510987900001},
doi = {10.1002/aenm.202500159},
issn = {1614-6832},
year = {2025},
date = {2025-06-19},
journal = {Advanced Energy Materials},
abstract = {Ammonia is industrially synthesized over multi-promoted Fe-based catalysts for more than a century. Although ammonia synthesis reflects a prototypical catalytic reaction, rational catalyst design is still impossible as the full structural complexity of this catalyst system often referred to as ammonia iron and its structural entanglement is barely understood. Here, the mesoscopic structure of a technical, multi-promoted ammonia synthesis catalyst is uncovered using a scale-bridging electron microscopy approach complemented by X-ray diffraction and spectroscopy to explore the structural integrity of ammonia iron. Amorphous contributions and structures of the melilite type and tricalcium aluminate as additional phases are identified. Furthermore, the understanding of the ammonia iron family by unveiling the role of the platelet-Fe perimeter, framework Fe, thin film Fe, and refractory Fe is extended. Their interconnectedness is highlighted, suggesting that each component has to be present to fulfill a specific task. The study demonstrates that catalysis science can only proceed if it openly explores the full complexity of catalytic systems.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Ammonia is industrially synthesized over multi-promoted Fe-based catalysts for more than a century. Although ammonia synthesis reflects a prototypical catalytic reaction, rational catalyst design is still impossible as the full structural complexity of this catalyst system often referred to as ammonia iron and its structural entanglement is barely understood. Here, the mesoscopic structure of a technical, multi-promoted ammonia synthesis catalyst is uncovered using a scale-bridging electron microscopy approach complemented by X-ray diffraction and spectroscopy to explore the structural integrity of ammonia iron. Amorphous contributions and structures of the melilite type and tricalcium aluminate as additional phases are identified. Furthermore, the understanding of the ammonia iron family by unveiling the role of the platelet-Fe perimeter, framework Fe, thin film Fe, and refractory Fe is extended. Their interconnectedness is highlighted, suggesting that each component has to be present to fulfill a specific task. The study demonstrates that catalysis science can only proceed if it openly explores the full complexity of catalytic systems.
9.
L J Falling, W Jang, S Laha, T Götsch, M W Terban, S Bette, R Mom, J-J Velasco-Vélez, F Girgsdies, D Teschner, A Tarasov, C-H Chuang, T Lunkenbein, A Knop-Gericke, D Weber, R Dinnebier, B V Lotsch, R Schlögl, T E Jones
Atomic Insights into the Competitive Edge of Nanosheets Splitting Water Journal Article
In: Journal of the American Chemical Society, vol. 146, no. 40, pp. 27886-27902, 2024, ISSN: 0002-7863.
@article{nokey,
title = {Atomic Insights into the Competitive Edge of Nanosheets Splitting Water},
author = {L J Falling and W Jang and S Laha and T G\"{o}tsch and M W Terban and S Bette and R Mom and J-J Velasco-V\'{e}lez and F Girgsdies and D Teschner and A Tarasov and C-H Chuang and T Lunkenbein and A Knop-Gericke and D Weber and R Dinnebier and B V Lotsch and R Schl\"{o}gl and T E Jones},
url = {https://doi.org/10.1021/jacs.4c10312},
doi = {10.1021/jacs.4c10312},
issn = {0002-7863},
year = {2024},
date = {2024-10-09},
journal = {Journal of the American Chemical Society},
volume = {146},
number = {40},
pages = {27886-27902},
abstract = {The oxygen evolution reaction (OER) provides the protons for many electrocatalytic power-to-X processes, such as the production of green hydrogen from water or methanol from CO2. Iridium oxohydroxides (IOHs) are outstanding catalysts for this reaction because they strike a unique balance between activity and stability in acidic electrolytes. Within IOHs, this balance varies with the atomic structure. While amorphous IOHs perform best, they are least stable. The opposite is true for their crystalline counterparts. These rules-of-thumb are used to reduce the loading of scarce IOH catalysts and retain the performance. However, it is not fully understood how activity and stability are related at the atomic level, hampering rational design. Herein, we provide simple design rules (Figure 12) derived from the literature and various IOHs within this study. We chose crystalline IrOOH nanosheets as our lead material because they provide excellent catalyst utilization and a predictable structure. We found that IrOOH signals the chemical stability of crystalline IOHs while surpassing the activity of amorphous IOHs. Their dense bonding network of pyramidal trivalent oxygens (μ3Δ-O) provides structural integrity, while allowing reversible reduction to an electronically gapped state that diminishes the destructive effect of reductive potentials. The reactivity originates from coordinative unsaturated edge sites with radical character, i.e., μ1-O oxyls. By comparing to other IOHs and literature, we generalized our findings and synthesized a set of simple rules that allow prediction of stability and reactivity of IOHs from atomistic models. We hope that these rules will inspire atomic design strategies for future OER catalysts.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The oxygen evolution reaction (OER) provides the protons for many electrocatalytic power-to-X processes, such as the production of green hydrogen from water or methanol from CO2. Iridium oxohydroxides (IOHs) are outstanding catalysts for this reaction because they strike a unique balance between activity and stability in acidic electrolytes. Within IOHs, this balance varies with the atomic structure. While amorphous IOHs perform best, they are least stable. The opposite is true for their crystalline counterparts. These rules-of-thumb are used to reduce the loading of scarce IOH catalysts and retain the performance. However, it is not fully understood how activity and stability are related at the atomic level, hampering rational design. Herein, we provide simple design rules (Figure 12) derived from the literature and various IOHs within this study. We chose crystalline IrOOH nanosheets as our lead material because they provide excellent catalyst utilization and a predictable structure. We found that IrOOH signals the chemical stability of crystalline IOHs while surpassing the activity of amorphous IOHs. Their dense bonding network of pyramidal trivalent oxygens (μ3Δ-O) provides structural integrity, while allowing reversible reduction to an electronically gapped state that diminishes the destructive effect of reductive potentials. The reactivity originates from coordinative unsaturated edge sites with radical character, i.e., μ1-O oxyls. By comparing to other IOHs and literature, we generalized our findings and synthesized a set of simple rules that allow prediction of stability and reactivity of IOHs from atomistic models. We hope that these rules will inspire atomic design strategies for future OER catalysts.
8.
L Masliuk, K Nam, M W Terban, Y Lee, P Kube, D Delgado, F Girgsdies, K Reuter, R Schlögl, A Trunschke, C Scheurer, M Zobel, T Lunkenbein
Linking Bulk and Surface Structures in Complex Mixed Oxides Journal Article
In: ACS Catalysis, vol. 14, no. 11, pp. 9018-9033, 2024.
@article{nokey,
title = {Linking Bulk and Surface Structures in Complex Mixed Oxides},
author = {L Masliuk and K Nam and M W Terban and Y Lee and P Kube and D Delgado and F Girgsdies and K Reuter and R Schl\"{o}gl and A Trunschke and C Scheurer and M Zobel and T Lunkenbein},
url = {https://doi.org/10.1021/acscatal.3c05230},
doi = {10.1021/acscatal.3c05230},
year = {2024},
date = {2024-06-07},
journal = {ACS Catalysis},
volume = {14},
number = {11},
pages = {9018-9033},
abstract = {The interface between a solid catalyst and the reacting medium plays a crucial role in the function of the material in catalysis. In the present work, we show that the surface termination of isostructural molybdenum\textendashvanadium oxides is strongly linked to the real structure of the bulk. This conclusion is based on comparing (scanning) transmission electron microscopy images with pair distribution function (PDF) data obtained for (Mo,V)Ox and (Mo,V,Te,Nb)Ox. Distance-dependent analyses of the PDF results demonstrate that (Mo,V,Te,Nb)Ox exhibits stronger deviations from the averaged orthorhombic crystal structure than (Mo,V)Ox in the short and intermediate regimes. These deviations are explained by higher structural diversity, which is facilitated by the increased chemical complexity of the quinary oxide and in particular by the presence of Nb. This structural diversity is seemingly important to form intrinsic bulk-like surface terminations that are highly selective in alkane oxidation. More rigid (Mo,V)Ox is characterized by defective surfaces that are more active but less selective for the same reactions. In line with machine learning interatomic potential (MLIP) calculations, we highlight that the surface termination of (Mo,V,Te,Nb)Ox is characterized by a reconfiguration of the pentagonal building blocks, causing a preferential exposure of Nb sites. The presented results foster hypotheses that chemical complexity is superior for the performance of multifunctional catalysts. The underlying principle is not the presence of multiple chemically different surface centers but instead the ability of structural diversity to optimally align and distribute the elements at the surface and, thus, to shape the structural environment around the active sites. This study experimentally evidences the origin of the structure-directing impact of the real structure of the bulk on functional interfaces and encourages the development of efficient surface engineering strategies toward improved high-performance selective oxidation catalysts.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The interface between a solid catalyst and the reacting medium plays a crucial role in the function of the material in catalysis. In the present work, we show that the surface termination of isostructural molybdenum–vanadium oxides is strongly linked to the real structure of the bulk. This conclusion is based on comparing (scanning) transmission electron microscopy images with pair distribution function (PDF) data obtained for (Mo,V)Ox and (Mo,V,Te,Nb)Ox. Distance-dependent analyses of the PDF results demonstrate that (Mo,V,Te,Nb)Ox exhibits stronger deviations from the averaged orthorhombic crystal structure than (Mo,V)Ox in the short and intermediate regimes. These deviations are explained by higher structural diversity, which is facilitated by the increased chemical complexity of the quinary oxide and in particular by the presence of Nb. This structural diversity is seemingly important to form intrinsic bulk-like surface terminations that are highly selective in alkane oxidation. More rigid (Mo,V)Ox is characterized by defective surfaces that are more active but less selective for the same reactions. In line with machine learning interatomic potential (MLIP) calculations, we highlight that the surface termination of (Mo,V,Te,Nb)Ox is characterized by a reconfiguration of the pentagonal building blocks, causing a preferential exposure of Nb sites. The presented results foster hypotheses that chemical complexity is superior for the performance of multifunctional catalysts. The underlying principle is not the presence of multiple chemically different surface centers but instead the ability of structural diversity to optimally align and distribute the elements at the surface and, thus, to shape the structural environment around the active sites. This study experimentally evidences the origin of the structure-directing impact of the real structure of the bulk on functional interfaces and encourages the development of efficient surface engineering strategies toward improved high-performance selective oxidation catalysts.
7.
L Sandoval-Diaz, D Cruz, M Vuijk, G Ducci, M Hävecker, W Jiang, M Plodinec, A Hammud, D Ivanov, T Götsch, K Reuter, R Schlögl, C Scheurer, A Knop-Gericke, T Lunkenbein
Metastable nickel–oxygen species modulate rate oscillations during dry reforming of methane Journal Article
In: Nature Catalysis, vol. 7, no. 2, pp. 161-171, 2024, ISSN: 2520-1158.
@article{nokey,
title = {Metastable nickel\textendashoxygen species modulate rate oscillations during dry reforming of methane},
author = {L Sandoval-Diaz and D Cruz and M Vuijk and G Ducci and M H\"{a}vecker and W Jiang and M Plodinec and A Hammud and D Ivanov and T G\"{o}tsch and K Reuter and R Schl\"{o}gl and C Scheurer and A Knop-Gericke and T Lunkenbein},
url = {https://doi.org/10.1038/s41929-023-01090-4},
doi = {10.1038/s41929-023-01090-4},
issn = {2520-1158},
year = {2024},
date = {2024-02-01},
journal = {Nature Catalysis},
volume = {7},
number = {2},
pages = {161-171},
abstract = {When a heterogeneous catalyst is active, it forms metastable structures that constantly transform into each other. These structures contribute differently to the catalytic function. Here we show the role of different metastable oxygen species on a Ni catalyst during dry reforming of methane by combining environmental scanning electron microscopy, near ambient pressure X-ray photoelectron spectroscopy, on-line product detection and computer vision. We highlight the critical role of dissociative CO2 adsorption in regulating the oxygen content of the catalyst and in CH4 activation. We also discover rate oscillations during dry reforming of methane resulting from the sequential transformation of metastable oxygen species that exhibit different catalytic properties: atomic surface oxygen, subsurface oxygen and bulk NiOx. The imaging approach allowed the localization of fluctuating surface regions that correlated directly with catalytic activity. The study highlights the importance of metastability and operando analytics in catalysis science and provides impetus towards the design of catalytic systems.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
When a heterogeneous catalyst is active, it forms metastable structures that constantly transform into each other. These structures contribute differently to the catalytic function. Here we show the role of different metastable oxygen species on a Ni catalyst during dry reforming of methane by combining environmental scanning electron microscopy, near ambient pressure X-ray photoelectron spectroscopy, on-line product detection and computer vision. We highlight the critical role of dissociative CO2 adsorption in regulating the oxygen content of the catalyst and in CH4 activation. We also discover rate oscillations during dry reforming of methane resulting from the sequential transformation of metastable oxygen species that exhibit different catalytic properties: atomic surface oxygen, subsurface oxygen and bulk NiOx. The imaging approach allowed the localization of fluctuating surface regions that correlated directly with catalytic activity. The study highlights the importance of metastability and operando analytics in catalysis science and provides impetus towards the design of catalytic systems.
6.
R V Mom, L-E Sandoval-Diaz, D Gao, C-H Chuang, E A Carbonio, T E Jones, R Arrigo, D Ivanov, M Hävecker, B Roldan Cuenya, R Schlögl, T Lunkenbein, A Knop-Gericke, J-J Velasco-Vélez
Assessment of the Degradation Mechanisms of Cu Electrodes during the CO2 Reduction Reaction Journal Article
In: ACS Applied Materials & Interfaces, vol. 15, no. 25, pp. 30052-30059, 2023, ISSN: 1944-8244.
@article{nokey,
title = {Assessment of the Degradation Mechanisms of Cu Electrodes during the CO2 Reduction Reaction},
author = {R V Mom and L-E Sandoval-Diaz and D Gao and C-H Chuang and E A Carbonio and T E Jones and R Arrigo and D Ivanov and M H\"{a}vecker and B Roldan Cuenya and R Schl\"{o}gl and T Lunkenbein and A Knop-Gericke and J-J Velasco-V\'{e}lez},
url = {https://doi.org/10.1021/acsami.2c23007},
doi = {10.1021/acsami.2c23007},
issn = {1944-8244},
year = {2023},
date = {2023-06-15},
journal = {ACS Applied Materials \& Interfaces},
volume = {15},
number = {25},
pages = {30052-30059},
abstract = {Catalyst degradation and product selectivity changes are two of the key challenges in the electrochemical reduction of CO2 on copper electrodes. Yet, these aspects are often overlooked. Here, we combine in situ X-ray spectroscopy, in situ electron microscopy, and ex situ characterization techniques to follow the long-term evolution of the catalyst morphology, electronic structure, surface composition, activity, and product selectivity of Cu nanosized crystals during the CO2 reduction reaction. We found no changes in the electronic structure of the electrode under cathodic potentiostatic control over time, nor was there any build-up of contaminants. In contrast, the electrode morphology is modified by prolonged CO2 electroreduction, which transforms the initially faceted Cu particles into a rough/rounded structure. In conjunction with these morphological changes, the current increases and the selectivity changes from value-added hydrocarbons to less valuable side reaction products, i.e., hydrogen and CO. Hence, our results suggest that the stabilization of a faceted Cu morphology is pivotal for ensuring optimal long-term performance in the selective reduction of CO2 into hydrocarbons and oxygenated products.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Catalyst degradation and product selectivity changes are two of the key challenges in the electrochemical reduction of CO2 on copper electrodes. Yet, these aspects are often overlooked. Here, we combine in situ X-ray spectroscopy, in situ electron microscopy, and ex situ characterization techniques to follow the long-term evolution of the catalyst morphology, electronic structure, surface composition, activity, and product selectivity of Cu nanosized crystals during the CO2 reduction reaction. We found no changes in the electronic structure of the electrode under cathodic potentiostatic control over time, nor was there any build-up of contaminants. In contrast, the electrode morphology is modified by prolonged CO2 electroreduction, which transforms the initially faceted Cu particles into a rough/rounded structure. In conjunction with these morphological changes, the current increases and the selectivity changes from value-added hydrocarbons to less valuable side reaction products, i.e., hydrogen and CO. Hence, our results suggest that the stabilization of a faceted Cu morphology is pivotal for ensuring optimal long-term performance in the selective reduction of CO2 into hydrocarbons and oxygenated products.
5.
M Plodinec, H C Nerl, T Lunkenbein, R Schlögl
Deactivation Mechanism of Ni Nanoparticles in Dry Reforming of Methane Revealed by Operando TEM Journal Article
In: Microscopy and Microanalysis, vol. 28, no. S1, pp. 146-148, 2022, ISSN: 1431-9276.
@article{nokey,
title = {Deactivation Mechanism of Ni Nanoparticles in Dry Reforming of Methane Revealed by Operando TEM},
author = {M Plodinec and H C Nerl and T Lunkenbein and R Schl\"{o}gl},
url = {https://doi.org/10.1017/S1431927622001489},
doi = {10.1017/s1431927622001489},
issn = {1431-9276},
year = {2022},
date = {2022-08-01},
journal = {Microscopy and Microanalysis},
volume = {28},
number = {S1},
pages = {146-148},
abstract = {Many studies have shown that catalysts are metastable and dynamic systems, where the nature of the active state depends on the applied chemical potential, associated “chemical dynamics” and the formation of transient active sites. Therefore, active surfaces could be unstable at non-active conditions, leading to misinterpretation of inactive structures as active states in ex situ studies. Recent progress in the development of in situ and operando techniques allows access to live information at high temporal and spatial resolution for the first time. Operando transmission electron microscopy (TEM) allows to directly probe the active-state/-sites of catalysts under relevant reaction conditions and at high resolution. The structure-function relationship remains unsolved in many catalytic reactions, including in the important industrial reaction - dry reforming of methane (DRM). This lack of fundamental understanding of DRM is hindering the choice and design of efficient catalyst material since an empirical approach to discovering new catalysts still prevails. Using operando TEM techniques presents a unique opportunity to gain fundamental insights into the DRM reaction to reveal what constitutes the active structure.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Many studies have shown that catalysts are metastable and dynamic systems, where the nature of the active state depends on the applied chemical potential, associated “chemical dynamics” and the formation of transient active sites. Therefore, active surfaces could be unstable at non-active conditions, leading to misinterpretation of inactive structures as active states in ex situ studies. Recent progress in the development of in situ and operando techniques allows access to live information at high temporal and spatial resolution for the first time. Operando transmission electron microscopy (TEM) allows to directly probe the active-state/-sites of catalysts under relevant reaction conditions and at high resolution. The structure-function relationship remains unsolved in many catalytic reactions, including in the important industrial reaction - dry reforming of methane (DRM). This lack of fundamental understanding of DRM is hindering the choice and design of efficient catalyst material since an empirical approach to discovering new catalysts still prevails. Using operando TEM techniques presents a unique opportunity to gain fundamental insights into the DRM reaction to reveal what constitutes the active structure.
4.
H Türk, T Götsch, F-P Schmidt, A Hammud, D Ivanov, L G J De Haart, I Vinke, R-A Eichel, R Schlögl, K Reuter, A Knop-Gericke, T Lunkenbein, C Scheurer
Sr Surface Enrichment in Solid Oxide Cells - Approaching the Limits of EDX Analysis by Multivariate Statistical Analysis and Simulations Journal Article
In: ChemCatChem, vol. n/a, no. n/a, 2022, ISSN: 1867-3880.
@article{nokey,
title = {Sr Surface Enrichment in Solid Oxide Cells - Approaching the Limits of EDX Analysis by Multivariate Statistical Analysis and Simulations},
author = {H T\"{u}rk and T G\"{o}tsch and F-P Schmidt and A Hammud and D Ivanov and L G J De Haart and I Vinke and R-A Eichel and R Schl\"{o}gl and K Reuter and A Knop-Gericke and T Lunkenbein and C Scheurer},
url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/cctc.202200300},
doi = {https://doi.org/10.1002/cctc.202200300},
issn = {1867-3880},
year = {2022},
date = {2022-07-08},
journal = {ChemCatChem},
volume = {n/a},
number = {n/a},
abstract = {In solid oxide cells, Sr segregation has been correlated with degradation. Yet, the atomistic mechanism remains unknown. Here we begin to localize the origin of Sr surface nucleation by combining force field based simulations, energy dispersive X-ray spectroscopy (EDX) and multi-variate statistical analysis. We find increased ion mobility in the complexion between yttria-stabilized zirconia and strontium-doped lanthanum manganite. Furthermore, we developed a robust and automated routine to detect localized nucleation seeds of Sr at the complexion/vacuum interface. This hints at a mechanism originating at the complexion and requires in-depths studies at the atomistic level, where the developed routine can be beneficial for analysing large hyperspectral EDX datasets.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In solid oxide cells, Sr segregation has been correlated with degradation. Yet, the atomistic mechanism remains unknown. Here we begin to localize the origin of Sr surface nucleation by combining force field based simulations, energy dispersive X-ray spectroscopy (EDX) and multi-variate statistical analysis. We find increased ion mobility in the complexion between yttria-stabilized zirconia and strontium-doped lanthanum manganite. Furthermore, we developed a robust and automated routine to detect localized nucleation seeds of Sr at the complexion/vacuum interface. This hints at a mechanism originating at the complexion and requires in-depths studies at the atomistic level, where the developed routine can be beneficial for analysing large hyperspectral EDX datasets.
3.
H Türk, F-P Schmidt, T Götsch, F Girgsdies, A Hammud, D Ivanov, I C Vinke, L G J De Haart, R-A Eichel, K Reuter, R Schlögl, A Knop-Gericke, C Scheurer, T Lunkenbein
Complexions at the Electrolyte/Electrode Interface in Solid Oxide Cells Journal Article
In: Advanced Materials Interfaces, vol. 8, no. 18, pp. 2100967, 2021, ISSN: 2196-7350.
@article{nokey,
title = {Complexions at the Electrolyte/Electrode Interface in Solid Oxide Cells},
author = {H T\"{u}rk and F-P Schmidt and T G\"{o}tsch and F Girgsdies and A Hammud and D Ivanov and I C Vinke and L G J De Haart and R-A Eichel and K Reuter and R Schl\"{o}gl and A Knop-Gericke and C Scheurer and T Lunkenbein},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/admi.202100967},
doi = {https://doi.org/10.1002/admi.202100967},
issn = {2196-7350},
year = {2021},
date = {2021-08-21},
journal = {Advanced Materials Interfaces},
volume = {8},
number = {18},
pages = {2100967},
abstract = {Abstract Rapid deactivation presently limits a wide spread use of high-temperature solid oxide cells (SOCs) as otherwise highly efficient chemical energy converters. With deactivation triggered by the ongoing conversion reactions, an atomic-scale understanding of the active triple-phase boundary between electrolyte, electrode, and gas phase is essential to increase cell performance. Here, a multi-method approach is used comprising transmission electron microscopy and first-principles calculations and molecular simulations to untangle the atomic arrangement of the prototypical SOC interface between a lanthanum strontium manganite (LSM) anode and a yttria-stabilized zirconia (YSZ) electrolyte in the as-prepared state after sintering. An interlayer of self-limited width with partial amorphization and strong compositional gradient is identified, thus exhibiting the characteristics of a complexion that is stabilized by the confinement between two bulk phases. This offers a new perspective to understand the function of SOCs at the atomic scale. Moreover, it opens up a hitherto unrealized design space to tune the conversion efficiency.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Abstract Rapid deactivation presently limits a wide spread use of high-temperature solid oxide cells (SOCs) as otherwise highly efficient chemical energy converters. With deactivation triggered by the ongoing conversion reactions, an atomic-scale understanding of the active triple-phase boundary between electrolyte, electrode, and gas phase is essential to increase cell performance. Here, a multi-method approach is used comprising transmission electron microscopy and first-principles calculations and molecular simulations to untangle the atomic arrangement of the prototypical SOC interface between a lanthanum strontium manganite (LSM) anode and a yttria-stabilized zirconia (YSZ) electrolyte in the as-prepared state after sintering. An interlayer of self-limited width with partial amorphization and strong compositional gradient is identified, thus exhibiting the characteristics of a complexion that is stabilized by the confinement between two bulk phases. This offers a new perspective to understand the function of SOCs at the atomic scale. Moreover, it opens up a hitherto unrealized design space to tune the conversion efficiency.
2.
T Götsch, H Tuerk, F-P Schmidt, I Vinke, De L B Haart, R Schlögl, K Reuter, R-A Eichel, A Knop-Gericke, C Scheurer
Visualizing the Atomic Structure Between YSZ and LSM: An Interface Stabilized by Complexions? Journal Article
In: ECS Transactions, vol. 103, no. 1, pp. 1331, 2021, ISSN: 1938-5862.
@article{,
title = {Visualizing the Atomic Structure Between YSZ and LSM: An Interface Stabilized by Complexions?},
author = {T G\"{o}tsch and H Tuerk and F-P Schmidt and I Vinke and De L B Haart and R Schl\"{o}gl and K Reuter and R-A Eichel and A Knop-Gericke and C Scheurer},
issn = {1938-5862},
year = {2021},
date = {2021-07-12},
urldate = {2021-07-12},
journal = {ECS Transactions},
volume = {103},
number = {1},
pages = {1331},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
1.
M Boniface, M Plodinec, R Schlögl, T Lunkenbein
Quo Vadis Micro-Electro-Mechanical Systems for the Study of Heterogeneous Catalysts Inside the Electron Microscope? Journal Article
In: Topics in Catalysis, vol. 63, no. 15, pp. 1623-1643, 2020, ISSN: 1572-9028.
@article{nokey,
title = {Quo Vadis Micro-Electro-Mechanical Systems for the Study of Heterogeneous Catalysts Inside the Electron Microscope?},
author = {M Boniface and M Plodinec and R Schl\"{o}gl and T Lunkenbein},
url = {https://doi.org/10.1007/s11244-020-01398-6},
doi = {10.1007/s11244-020-01398-6},
issn = {1572-9028},
year = {2020},
date = {2020-11-01},
journal = {Topics in Catalysis},
volume = {63},
number = {15},
pages = {1623-1643},
abstract = {During the last decade, modern micro-electro-mechanical systems (MEMS) technology has been used to create cells that can act as catalytic nanoreactors and fit into the sample holders of transmission electron microscopes. These nanoreactors can maintain atmospheric or higher pressures inside the cells as they seal gases or liquids from the vacuum of the TEM column and can reach temperatures exceeding 1000 °C. This has led to a paradigm shift in electron microscopy, which facilitates the local characterization of structural and morphological changes of solid catalysts under working conditions. In this review, we outline the development of state-of-the-art nanoreactor setups that are commercially available and are currently applied to study catalytic reactions in situ or operando in gaseous or liquid environments. We also discuss challenges that are associated with the use of environmental cells. In catalysis studies, one of the major challenge is the interpretation of the results while considering the discrepancies in kinetics between MEMS based gas cells and fixed bed reactors, the interactions of the electron beam with the sample, as well as support effects. Finally, we critically analyze the general role of MEMS based nanoreactors in electron microscopy and catalysis communities and present possible future directions.},
keywords = {},
pubstate = {published},
tppubtype = {article}
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During the last decade, modern micro-electro-mechanical systems (MEMS) technology has been used to create cells that can act as catalytic nanoreactors and fit into the sample holders of transmission electron microscopes. These nanoreactors can maintain atmospheric or higher pressures inside the cells as they seal gases or liquids from the vacuum of the TEM column and can reach temperatures exceeding 1000 °C. This has led to a paradigm shift in electron microscopy, which facilitates the local characterization of structural and morphological changes of solid catalysts under working conditions. In this review, we outline the development of state-of-the-art nanoreactor setups that are commercially available and are currently applied to study catalytic reactions in situ or operando in gaseous or liquid environments. We also discuss challenges that are associated with the use of environmental cells. In catalysis studies, one of the major challenge is the interpretation of the results while considering the discrepancies in kinetics between MEMS based gas cells and fixed bed reactors, the interactions of the electron beam with the sample, as well as support effects. Finally, we critically analyze the general role of MEMS based nanoreactors in electron microscopy and catalysis communities and present possible future directions.