Einfluss der Katalysator-Träger-Wechselwirkung auf die Aktivität und Stabilität von Wasserspaltungs-Katalysatoren
Zusammenfassung der Projektergebnisse
In this project, we studied the role of the interface between catalyst and substrate in photoelectrochemical (PEC) devices used for the OER. We investigated the PEC prototype catalyst|support systems Ti/TiOx and Ti/TiOx/M (M = Au, Ni, Fe) with NiFe layered double hydroxides (NiFe LDH) on top. The metal interlayer M leads to a 100-fold increase of the OER current. We employed electrochemical voltammetry and impedance methods as well as x-ray spectroscopic methods on drop casted NiFe LDH and compared results with NiFeOx thin film model systems. With ex-situ and in-situ methods, we show that both the NiFe LDH as well as the thin film systems undergo comparable transitions of the starting catalyst material into the highly active (oxy)hydroxide phase, when using metallic interlayers. In parallel with this activation, the interface between catalyst and metal modified substrate becomes permissive to currents. It is known that the higher oxidized (oxy)hydroxide phases are more conductive, however, we could not finally conclude whether an initial better interface conductivity between substrate and catalyst leads to a better catalyst conversion or if instead an initially better interface coupling alignment allows for an efficient conversion of the catalyst. We have shown that our interface experiments on thin-film model systems are representative for more complicated practical electrolysis structures, and they provide more detailed insight into the electronic coupling between substrate, metal interlayer and catalyst. However, the exact mechanism for the better OER performance of these systems stays elusive, yet. Related to the molecular systems for the hydrogen evolution reaction (HER), variations in the ligand environment, metal center and on substituents were performed to unravel the dominating factor for the catalytic activity. Based on the results, it can be generalized that Cobased systems outperform Fe-based systems by almost 100 mV less overpotential. In order to enable in-situ and operando spectroscopy, pre-tests were performed with a flow cell. However, further improvement was obtained by changing from Mössbauer spectroscopy to NFS. On the basis of these results, we were able to determine the intermediate that is formed prior to the rate determining step. In order to gain insights on the role of the support, three different supports were used. The comparison of the electrochemical data and the vibrational spectra after pyrolysis in a temperature range from 600 – 800 °C indicate that in parallel to the increase in performance also the binding strength of the metal center towards the surround matrix became stronger. The analysis of the corresponding in-situ data is still ongoing but will help to conclude on similarities and differences of the pyrolyzed MNC in comparison to nonpyrolyzed porphyrinic systems.
Projektbezogene Publikationen (Auswahl)
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In-situ structure and catalytic mechanism of NiFe and CoFe layered double hydroxides during oxygen evolution. Nature Communications, 11(1).
Dionigi, Fabio; Zeng, Zhenhua; Sinev, Ilya; Merzdorf, Thomas; Deshpande, Siddharth; Lopez, Miguel Bernal; Kunze, Sebastian; Zegkinoglou, Ioannis; Sarodnik, Hannes; Fan, Dingxin; Bergmann, Arno; Drnec, Jakub; Araujo, Jorge Ferreira de; Gliech, Manuel; Teschner, Detre; Zhu, Jing; Li, Wei-Xue; Greeley, Jeffrey; Cuenya, Beatriz Roldan & Strasser, Peter
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Manganese Oxide as an Inorganic Catalyst for the Oxygen Evolution Reaction Studied by X‐Ray Photoelectron and Operando Raman Spectroscopy. ChemCatChem, 13(4), 1175-1185.
Radinger, Hannes; Connor, Paula; Stark, Robert; Jaegermann, Wolfram & Kaiser, Bernhard
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Importance of Nickel Oxide Lattice Defects for Efficient Oxygen Evolution Reaction. Chemistry of Materials, 33(21), 8259-8266.
Radinger, Hannes; Connor, Paula; Tengeler, Sven; Stark, Robert W.; Jaegermann, Wolfram & Kaiser, Bernhard
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Formation of Highly Active NiO(OH) Thin Films from Electrochemically Deposited Ni(OH)2 by a Simple Thermal Treatment at a Moderate Temperature: A Combined Electrochemical and Surface Science Investigation. ACS Catalysis, 12(2), 1508-1519.
Tao, Shasha; Wen, Qingbo; Jaegermann, Wolfram & Kaiser, Bernhard
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Impact of Ir modification on the durability of FeNC catalysts under start-up and shutdown cycle conditions. Journal of Materials Chemistry A, 10(11), 6038-6053.
Prössl, Carolin; Kübler, Markus; Paul, Stephen; Ni, Lingmei; Kinkelin, Simon-Johannes; Heppe, Nils; Eberhardt, Klaus; Geppert, Christopher; Jaegermann, Wolfram; Stark, Robert W.; Bron, Michael & Kramm, Ulrike I.
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Tandem Nanostructures: A Prospective Platform for Photoelectrochemical Water Splitting. Solar RRL, 6(9).
Liu, Jun; Zhao, Huaping; Wang, Zhijie; Hannappel, Thomas; Kramm, Ulrike I.; Etzold, Bastian J. M. & Lei, Yong
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Active Surface Area and Intrinsic Catalytic Oxygen Evolution Reactivity of NiFe LDH at Reactive Electrode Potentials Using Capacitances. ACS Catalysis, 13(2), 1186-1196.
Jeon, Sun Seo; Kang, Phil Woong; Klingenhof, Malte; Lee, Hyunjoo; Dionigi, Fabio & Strasser, Peter
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Effect of Metal Layer Support Structures on the Catalytic Activity of NiFe(oxy)hydroxide (LDH) for the OER in Alkaline Media. ChemCatChem, 15(8).
Gort, Christopher; Buchheister, Paul W.; Klingenhof, Malte; Paul, Stephen D.; Dionigi, Fabio; van de Krol, Roel; Kramm, Ulrike I.; Jaegermann, Wolfram; Hofmann, Jan P.; Strasser, Peter & Kaiser, Bernhard
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Operando studies of Mn oxide based electrocatalysts for the oxygen evolution reaction. Physical Chemistry Chemical Physics, 25(40), 26958-26971.
Erbe, Andreas; Tesch, Marc Frederic; Rüdiger, Olaf; Kaiser, Bernhard; DeBeer, Serena & Rabe, Martin
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Substituent Effects in Iron Porphyrin Catalysts for the Hydrogen Evolution Reaction**. Chemistry – A European Journal, 29(10).
Heppe, Nils; Gallenkamp, Charlotte; Paul, Stephen; Segura‐Salas, Nicole; von Rhein, Niklas; Kaiser, Bernhard; Jaegermann, Wolfram; Jafari, Atefeh; Sergueev, Ilya; Krewald, Vera & Kramm, Ulrike I.
