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Penner S. How the in situ monitoring of bulk crystalline phases during catalyst activation results in a better understanding of heterogeneous catalysis. CrystEngComm 2021; 23:6470-6480. [PMID: 34602861 PMCID: PMC8474056 DOI: 10.1039/d1ce00817j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 08/06/2021] [Indexed: 12/03/2022]
Abstract
The present Highlight article shows the importance of the in situ monitoring of bulk crystalline compounds for a more thorough understanding of heterogeneous catalysts at the intersection of catalysis, materials science, crystallography and inorganic chemistry. Although catalytic action is widely regarded as a purely surface-bound phenomenon, there is increasing evidence that bulk processes can detrimentally or beneficially influence the catalytic properties of various material classes. Such bulk processes include polymorphic transformations, formation of oxygen-deficient structures, transient phases and the formation of a metal-oxide composite. The monitoring of these processes and the subsequent establishment of structure-property relationships are most effective if carried out in situ under real operation conditions. By focusing on synchrotron-based in situ X-ray diffraction as the perfect tool to follow the evolution of crystalline species, we exemplify the strength of the concept with five examples from various areas of catalytic research. As catalyst activation studies are increasingly becoming a hot topic in heterogeneous catalysis, the (self-)activation of oxide- and intermetallic compound-based materials during methanol steam and methane dry reforming is highlighted. The perovskite LaNiO3 is selected as an example to show the complex structural dynamics before and during methane dry reforming, which is only revealed upon monitoring all intermediate crystalline species in the transformation from LaNiO3 into Ni/La2O3/La2O2CO3. ZrO2-based materials form the second group, indicating the in situ decomposition of the intermetallic compound Cu51Zr14 into an epitaxially stabilized Cu/tetragonal ZrO2 composite during methanol steam reforming, the stability of a ZrO0.31C0.69 oxycarbide and the gas-phase dependence of the tetragonal-to-monoclinic ZrO2 polymorphic transformation. The latter is the key parameter to the catalytic understanding of ZrO2 and is only appreciated in full detail once it is possible to follow the individual steps of the transformation between the crystalline polymorphic structures. A selected example is devoted to how the monitoring of crystalline reactive carbon during methane dry reforming operation aids in the mechanistic understanding of a Ni/MnO catalyst. The most important aspect is the strict use of in situ monitoring of the structural changes occurring during (self-)activation to establish meaningful structure-property relationships allowing conclusions beyond isolated surface chemical aspects.
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Affiliation(s)
- Simon Penner
- Institute of Physical Chemistry, University of Innsbruck Innrain 52c A-6020 Innsbruck Austria +4351250758003
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Shakibi Nia N, Hauser D, Schlicker L, Gili A, Doran A, Gurlo A, Penner S, Kunze-Liebhäuser J. Zirconium Oxycarbide: A Highly Stable Catalyst Material for Electrochemical Energy Conversion. Chemphyschem 2019; 20:3067-3073. [PMID: 31247128 PMCID: PMC6900196 DOI: 10.1002/cphc.201900539] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 06/26/2019] [Indexed: 11/26/2022]
Abstract
Metal carbides and oxycarbides have recently gained considerable interest due to their (electro)catalytic properties that differ from those of transition metals and that have potential to outperform them as well. The stability of zirconium oxycarbide nanopowders (ZrO0.31C0.69), synthesized via a hybrid solid‐liquid route, is investigated in different gas atmospheres from room temperature to 800 °C by using in‐situ X‐ray diffraction and in‐situ electrical impedance spectroscopy. To feature the properties of a structurally stable Zr oxycarbide with high oxygen content, a stoichiometry of ZrO0.31C0.69 has been selected. ZrO0.31C0.69 is stable in reducing gases with only minor amounts of tetragonal ZrO2 being formed at high temperatures, whereas it decomposes in CO2 and O2 gas atmosphere. From online differential electrochemical mass spectrometry measurements, the hydrogen evolution reaction (HER) onset potential is determined at −0.4 VRHE. CO2 formation is detected at potentials as positive as 1.9 VRHE as ZrO0.31C0.69 decomposition product, and oxygen is anodically formed at 2.5 VRHE, which shows the high electrochemical stability of this material in acidic electrolyte. This peopwery makes the material suited for electrocatalytic reactions at anodic potentials, such as CO and alcohol oxidation reactions, in general.
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Affiliation(s)
- Niusha Shakibi Nia
- Leopold-Franzens-Universität Innsbruck, Innrain 52c (Josef-Möller-Haus), A-6020, Innsbruck, Austria
| | - Daniel Hauser
- Leopold-Franzens-Universität Innsbruck, Innrain 52c (Josef-Möller-Haus), A-6020, Innsbruck, Austria
| | - Lukas Schlicker
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und -technologien, Technische Universität Berlin, Hardenbergstr. 40, 10623, Berlin, Germany
| | - Albert Gili
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und -technologien, Technische Universität Berlin, Hardenbergstr. 40, 10623, Berlin, Germany
| | - Andrew Doran
- Advanced Light Source, Lawrence National Laboratory Berkeley, California, 94720, USA
| | - Aleksander Gurlo
- Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials, Institut für Werkstoffwissenschaften und -technologien, Technische Universität Berlin, Hardenbergstr. 40, 10623, Berlin, Germany
| | - Simon Penner
- Leopold-Franzens-Universität Innsbruck, Innrain 52c (Josef-Möller-Haus), A-6020, Innsbruck, Austria
| | - Julia Kunze-Liebhäuser
- Leopold-Franzens-Universität Innsbruck, Innrain 52c (Josef-Möller-Haus), A-6020, Innsbruck, Austria
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Tao Y, Chang Q, Liu Q, Guan H, Yang G, Lang R, Chen G, Dong C. In situ fabrication of Ni(OH)2 nanoflakes/K-Ti-O nanowires on NiTi foil for high performance non-enzymatic hydrogen peroxide sensing. J Electroanal Chem (Lausanne) 2019. [DOI: 10.1016/j.jelechem.2019.04.050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Rüdiger C, Valero-Vidal C, Favaro M, Agnoli S, Granozzi G, Kunze-Liebhäuser J. Effect of Air-Aging on the Electrochemical Characteristics of TiO
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Films for Electrocatalysis Applications. ChemElectroChem 2017. [DOI: 10.1002/celc.201700912] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Celine Rüdiger
- Physik-Department; Technische Universität München; James-Franck-Str. 1 85748 Garching Germany
| | - Carlos Valero-Vidal
- Physik-Department; Technische Universität München; James-Franck-Str. 1 85748 Garching Germany
- Institut für Physikalische Chemie; Leopold-Franzens-Universität Innsbruck; Innrain 52c 6020 Innsbruck Austria
- Advanced Light Source (ALS) and; Joint Center for Energy Storage Research (JCESR), Lawrence Berkeley National Laboratory; 1 Cyclotron Road Berkeley CA 94720 United States
| | - Marco Favaro
- Dipartimento di Scienze Chimiche; Università di Padova Via Marzolo 1 35131 Padova Italy
- Helmholtz-Zentrum Berlin (HZB); Institute for Solar Fuels; Hahn-Meitner-Platz 1 14109 Berlin Germany
| | - Stefano Agnoli
- Dipartimento di Scienze Chimiche; Università di Padova Via Marzolo 1 35131 Padova Italy
| | - Gaetano Granozzi
- Dipartimento di Scienze Chimiche; Università di Padova Via Marzolo 1 35131 Padova Italy
| | - Julia Kunze-Liebhäuser
- Institut für Physikalische Chemie; Leopold-Franzens-Universität Innsbruck; Innrain 52c 6020 Innsbruck Austria
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