Supraparticles Composed of Graphitic Carbon Nitride Nanoparticles and Silica-Supported Horseradish Peroxidase as Customizable Hybrid Catalysts for Photo-Biocatalytic Cascade Reactions in Continuous Flow Bettina Herbig, Egzon Cermjani, Doris Hanselmann, Johannes Prieschl, Angelika Schmitt, Michael S. Moritz, Christian Papp, Greta Nölke, Stefano Di Fiore, Christoph Deckers, Thomas H. Rehm, Susanne Wintzheimer Advanced Functional Materials, 2026 In green and sustainable chemistry, coupling biocatalysis and photocatalysis in cascade processes is particularly appealing. It enables reactions at ambient temperature in aqueous solutions with light as an abundant energy source. Additionally, it merges the high reactivity of photocatalysts with the unique selectivity of biocatalysts. However, such cascade processes, especially when conducted in one‐pot mode, pose the challenges of mutual catalyst deactivation and opposite optimal conditions for each catalytic step. In this work, the design of hybrid supraparticles consisting of the nanoparticular photocatalyst graphitic carbon nitride and the enzyme horseradish peroxidase immobilized on silica nanoparticles is proposed. A compatibility range where both catalysts can coexist within the hybrid supraparticles and function effectively, both in one‐pot batch and continuous flow processes, is identified using the photocatalytic hydrogen peroxide production and the enzymatic 3,3′,5,5′‐tetramethylbenzidine conversion as a model cascade reaction.
Surface properties of Ga–Cu based liquid-metal alloys: impact of Cu dilution, topography, and alloy liquefaction Tzung-En Hsieh, Michael S. Moritz, Andreas Mölkner, Christoph Wichmann, Johannes Frisch, Julien Steffen, Caiden J. Parker, Vaishnavi Krishnamurthi, Torben Daeneke, Hans-Peter Steinrück, Andreas Görling, Christian Papp, Marcus Bär Rsc Applied Interfaces, 2026 Demonstration of structural and morphological evolution of Cu in the Ga matrix upon alloy formation and liquefaction.
The influence of GaPt droplet purification on the catalytic performance of supraparticles as supported catalytically active liquid metal solutions (SCALMS) in propane dehydrogenation Philipp Groppe, Thomas Zimmermann, Nnamdi Madubuko, Kevin Bürner, Yaoci Sheng, Christoph Wichmann, Michael S. Moritz, Joachim Czechowsky, Valentin Müller, Jörg Libuda, Peter Wasserscheid, Karl Mandel, Torben Daeneke, Jan-Dierk Grunwaldt, Christian Papp, Marco Haumann, Tanja Retzer, Nicola Taccardi, Susanne Wintzheimer Journal of Materials Chemistry A, 2026 GaPt nanocomposites are colloidally synthesized and purified using three washing procedures that directly affect the catalytic stability in propane dehydrogenation of supported catalytically active liquid metal solutions (SCALMS) fabricated thereof.
Operando Study of the Active Phase in Liquid GaPt Alloy Catalysts Michael S. Moritz, Christoph Wichmann, Marius Steinmetz, Hans‐Peter Steinrück, Christian Papp Small Science, 2026 The operando study investigates propane dehydrogenation (PDH) using a liquid gallium‐platinum catalyst based on the supported catalytically active liquid metal solutions (SCALMS) concept. The focus is on monitoring and analyzing the active phase during reaction using near‐ambient pressure X‐ray photoelectron spectroscopy (NAPXPS) combined with gas phase analysis. This approach proves practical in tracking surface changes and chemical states during catalytic reactions, providing real‐time insights into the catalyst behavior. PDH, an industrially significant reaction, is investigated using a GaPt SCALMS with 1 at.% Pt content. The findings reveal that metallic liquid GaPt SCALMS exhibit high activity, while the presence of oxygen in the feed stream significantly lowers the activity of the catalyst. While current liquid metal catalysts often experience an activation period, a pathway to achieving stable conversion rates right after the start is demonstrated. This stability lays a foundation for developing next‐generation catalysts with improved performance. The investigation also highlights the critical influence of oxidic Ga on catalytic activity, offering valuable guidance for optimizing catalyst design. Overall, the findings underscore the practical importance of NAPXPS in advancing the understanding of surface properties in catalytic systems.
First-Principles-Based Study of the Decomposition of Phenol and Hydroquinone on Pt(111) Combined with Quantitative Information from XPS Spectra to Address the Impact of Coverage and Number of Hydroxyl Functional Groups Alyssa J. R. Hensley, Naseeha Cardwell, Claudia Jirausch, Christian Papp, Reinhard Denecke, Jean-Sabin McEwen Journal of Physical Chemistry C, 2025 High Resolution Image Download MS PowerPoint Slide A combined first-principles-based and experimental X-ray photoelectron spectroscopy approach was used to investigate the thermal decomposition of two model biofuel compounds, phenol and hydroquinone, on Pt(111) at both low and high coverages. The DFT-based approach yields adsorption geometries and energies, activation barriers and core-level binding energy shifts for C 1s and O 1s. Increasing the coverage in the theoretical model leads to slight shifts in core-level binding energies─toward higher values for C 1s and lower values for O 1s. It also alters the energy profiles of the decomposition reaction pathway, resulting in weaker adsorption energies and changes in both reaction and activation barriers. At low temperatures, we observe a multilayer for phenol and hydroquinone upon adsorption, with desorption occurring at 200 and 270 K, respectively. Following desorption of the multilayer, decomposition proceeds via initial O–H bond scission, followed by two parallel pathways involving either C–H or C–C bond scission, whereby in the case of phenol C–H bond scission occurs first. We further provide characteristic core level binding energies by theoretical calculations that are subsequently used in experimental analyses, establishing a reference database for key spectra of phenolic functionalities applicable to a range of catalytic reactions.
Thermite Reactions within Liquid Gallium/Iron Oxide Supraparticles Triggered Via Induction Heating Theodor Raczka, Philipp Groppe, Katrin Hurle, Michael S. Moritz, Christian Papp, Karl Mandel, Susanne Wintzheimer ACS Applied Nano Materials, 2025 Thermite reactions are well-known for mixtures of aluminum and iron oxide. However, other reactive metals, such as gallium, were not studied in this application, and the use of induction as an external trigger for the thermite reaction has not been established. In this work, supraparticles of gallium and iron oxide nanoparticles were synthesized to combine a low melting point with inductive heating properties. The enabled thermite-like redox reactions generate temperatures up to 900 °C within seconds in an alternating magnetic field, tunable by the material’s gallium content. Induction heating profiles are thus significantly expanded and could be applied for targeted heat-on-demand.
Atomic Layer Deposition on Spray-Dried Supraparticles to Rationally Design Catalysts with Ultralow Noble Metal Loadings Philipp Groppe, Valentin Müller, Johannes Will, Xin Zhou, Kailun Zhang, Michael S. Moritz, Christian Papp, Jörg Libuda, Tanja Retzer, Erdmann Spiecker, Julien Bachmann, Karl Mandel, Susanne Wintzheimer Chemistry of Materials, 2025 The controlled assembly of supraparticles by using spray-drying enables the synthesis of nanoporous materials. Changing the size of the constituent nanoparticles or their agglomeration states provides access to a diverse range of pore frameworks. This turns supraparticles into ideal scaffolds in heterogeneous catalysis. The combination of supraparticles with atomic layer deposition (ALD) as a surface functionalization technique offers excellent control over the deposition of a functional material and its distribution over the scaffold on the nanoscale. This work reports the combination of SiO 2 supraparticles as tunable scaffolds and their loading with a platinum-based ALD catalyst. The deliberate adjustment of the scaffold pore framework via spray-drying and its effect on the catalyst deposition are highlighted. Furthermore, varying numbers of Pt ALD cycles are applied to explore the capability of the combination approach with respect to catalyst loading and Pt efficiency. High-resolution electron microscopy reveals ultrasmall Pt clusters deposited on the supraparticles after the very first ALD cycle. Using the hydrogenation of 4-nitrophenol as a demonstration, the impact of the pore framework and the Pt deposition variation in ALD on the catalytic functionality is investigated.
Engineering two-dimensional supramolecular self-assembly: The role of Cl atoms Alisson Ceccatto, Gustavo Ramon Campi, Vanessa Carreño Diaz, Eidsa Brenda da Costa Ferreira, Natalie J. Waleska-Wellnhofer, Eva Marie Freiberger, Simon Jaekel, Christian Papp, Hans-Peter Steinrück, Duncan John Mowbray, Abner de Siervo Flatchem, 2025
Reactivity of graphene-supported Co clusters Natalie J. Waleska-Wellnhofer, Sophie Arzig, Fabian Düll, Udo Bauer, Phiona Bachmann, Johann Steinhauer, Christian Papp, Thomas Risse Surface Science, 2024
Bromination of 2D materials Eva Marie Freiberger, Julien Steffen, Natalie J Waleska-Wellnhofer, Felix Hemauer, Valentin Schwaab, Andreas Görling, Hans-Peter Steinrück, Christian Papp Nanotechnology, 2024
Isolated Rh atoms in dehydrogenation catalysis Haiko Wittkämper, Rainer Hock, Matthias Weißer, Johannes Dallmann, Carola Vogel, Narayanan Raman, Nicola Taccardi, Marco Haumann, Peter Wasserscheid, Tzung-En Hsieh, Sven Maisel, Michael Moritz, Christoph Wichmann, Johannes Frisch, Mihaela Gorgoi, Regan G. Wilks, Marcus Bär, Mingjian Wu, Erdmann Spiecker, Andreas Görling, Tobias Unruh, Hans-Peter Steinrück, Christian Papp Scientific Reports, 2023
Nano-SMSI on Bimetallic FePt Clusters Natalie J. Waleska-Wellnhofer, Eva Marie Freiberger, Felix Hemauer, Valentin Schwaab, Christian Papp Journal of Physical Chemistry C, 2023
Molecular Stacking on Graphene Tao Wei, Xin Liu, Malte Kohring, Sabrin Al‐Fogra, Michael Moritz, Daniel Hemmeter, Ulrike Paap, Christian Papp, Hans‐Peter Steinrück, Julien Bachmann, Heiko B. Weber, Frank Hauke, Andreas Hirsch Angewandte Chemie International Edition, 2022
Oxidation induced restructuring of Rh-Ga SCALMS model catalyst systems Haiko Wittkämper, Sven Maisel, Mingjian Wu, Johannes Frisch, Regan G. Wilks, Mathias Grabau, Erdmann Spiecker, Marcus Bär, Andreas Görling, Hans-Peter Steinrück, Christian Papp Journal of Chemical Physics, 2020
Reaction of Hydrogen and Oxygen on h-BN Florian Späth, Johann Steinhauer, Fabian Düll, Udo Bauer, Philipp Bachmann, Hans-Peter Steinrück, Christian Papp Journal of Physical Chemistry C, 2020
Revisiting surface core-level shifts for ionic compounds Paul S. Bagus, Connie J. Nelin, Xunhua Zhao, Sergey V. Levchenko, Earl Davis, Xuefei Weng, Florian Späth, Christian Papp, Helmut Kuhlenbeck, Hans-Joachim Freund Physical Review B, 2019
Oxygen Functionalization of Hexagonal Boron Nitride on Ni(111) Florian Späth, Himadri R. Soni, Johann Steinhauer, Fabian Düll, Udo Bauer, Phillip Bachmann, Wolfgang Hieringer, Andreas Görling, Hans‐Peter Steinrück, Christian Papp Chemistry A European Journal, 2019
Lattice Opening upon Bulk Reductive Covalent Functionalization of Black Phosphorus Stefan Wild, Michael Fickert, Aleksandra Mitrovic, Vicent Lloret, Christian Neiss, José Alejandro Vidal‐Moya, Miguel Ángel Rivero‐Crespo, Antonio Leyva‐Pérez, Katharina Werbach, Herwig Peterlik, Mathias Grabau, Haiko Wittkämper, Christian Papp, Hans‐Peter Steinrück, Thomas Pichler, Andreas Görling, Frank Hauke, Gonzalo Abellán, Andreas Hirsch Angewandte Chemie International Edition, 2019
Gallium-rich Pd-Ga phases as supported liquid metal catalysts N. Taccardi, M. Grabau, J. Debuschewitz, M. Distaso, M. Brandl, R. Hock, F. Maier, C. Papp, J. Erhard, C. Neiss, W. Peukert, A. Görling, H.-P. Steinrück, P. Wasserscheid Nature Chemistry, 2017
Growth of Stable Surface Oxides on Pt(111) at Near-Ambient Pressures Donato Fantauzzi, Sandra Krick Calderón, Jonathan E. Mueller, Mathias Grabau, Christian Papp, Hans‐Peter Steinrück, Thomas P. Senftle, Adri C. T. van Duin, Timo Jacob Angewandte Chemie International Edition, 2017
Surface Reaction of CO on Carbide-Modified Mo(110) Christoph Gleichweit, Christian Neiss, Sven Maisel, Udo Bauer, Florian Späth, Oliver Höfert, Andreas Görling, Hans-Peter Steinrück, Christian Papp Journal of Physical Chemistry C, 2017
Surface Reactions of Dicyclohexylmethane on Pt(111) Christoph Gleichweit, Max Amende, Oliver Höfert, Tao Xu, Florian Späth, Nicole Brückner, Peter Wasserscheid, Jörg Libuda, Hans-Peter Steinrück, Christian Papp Journal of Physical Chemistry C, 2015
Hydrogen, chemically stored Nachrichten Aus Der Chemie, 2014
Graphene-templated growth of Pd nanoclusters Karin Gotterbarm, Christian Steiner, Carina Bronnbauer, Udo Bauer, Hans-Peter Steinrück, Sabine Maier, Christian Papp Journal of Physical Chemistry C, 2014
Growth and oxidation of graphene on Rh(111) Karin Gotterbarm, Wei Zhao, Oliver Höfert, Christoph Gleichweit, Christian Papp, Hans-Peter Steinrück Physical Chemistry Chemical Physics, 2013
Wet chemical synthesis of graphene Siegfried Eigler, Michael Enzelberger‐Heim, Stefan Grimm, Philipp Hofmann, Wolfgang Kroener, Andreas Geworski, Christoph Dotzer, Michael Röckert, Jie Xiao, Christian Papp, Ole Lytken, Hans‐Peter Steinrück, Paul Müller, Andreas Hirsch Advanced Materials, 2013
Dehydrogenation of dodecahydro-N-ethylcarbazole on Pt(111) Christoph Gleichweit, Max Amende, Stefan Schernich, Wei Zhao, Michael P. A. Lorenz, Oliver Höfert, Nicole Brückner, Peter Wasserscheid, Jörg Libuda, Hans‐Peter Steinrück, Christian Papp Chemsuschem, 2013
Growth and electronic structure of boron-doped graphene J. Gebhardt, R. J. Koch, W. Zhao, O. Höfert, K. Gotterbarm, S. Mammadov, C. Papp, A. Görling, H.-P. Steinrück, Th. Seyller Physical Review B Condensed Matter and Materials Physics, 2013
Growth and electronic structure of nitrogen-doped graphene on Ni(111) R. J. Koch, M. Weser, W. Zhao, F. Viñes, K. Gotterbarm, S. M. Kozlov, O. Höfert, M. Ostler, C. Papp, J. Gebhardt, H.-P. Steinrück, A. Görling, Th. Seyller Physical Review B Condensed Matter and Materials Physics, 2012
Dehydrogenation of dodecahydro-N-ethylcarbazole on Pd/Al2O 3 model catalysts Marek Sobota, Ioannis Nikiforidis, Max Amende, Beatriz Sanmartín Zanón, Thorsten Staudt, Oliver Höfert, Yaroslava Lykhach, Christian Papp, Wolfgang Hieringer, Mathias Laurin, Daniel Assenbaum, Peter Wasserscheid, Hans‐Peter Steinrück, Andreas Görling, Jörg Libuda Chemistry A European Journal, 2011
Hard x-ray photoemission using standing-wave excitation applied to the MgO/Fe interface Sven Döring, Frank Schönbohm, Ulf Berges, Reinert Schreiber, Daniel E. Bürgler, Claus M. Schneider, Mihaela Gorgoi, Franz Schäfers, Christian Papp, Benjamin Balke, Charles S. Fadley, Carsten Westphal Physical Review B Condensed Matter and Materials Physics, 2011
Graphene on Ni(111): Coexistence of different surface structures Wei Zhao, Sergey M. Kozlov, Oliver Höfert, Karin Gotterbarm, Michael P. A. Lorenz, Francesc Viñes, Christian Papp, Andreas Görling, Hans-Peter Steinrück Journal of Physical Chemistry Letters, 2011
Covalent bulk functionalization of graphene Jan M. Englert, Christoph Dotzer, Guang Yang, Martin Schmid, Christian Papp, J. Michael Gottfried, Hans-Peter Steinrück, Erdmann Spiecker, Frank Hauke, Andreas Hirsch Nature Chemistry, 2011
Cost-benefit analysis for home smoke detector using the Life Quality Index Technische Sicherheit, 2011
Sulfur oxidation on Pt(355): It is the steps! Regine Streber, Christian Papp, Michael P. A. Lorenz, Andreas Bayer, Reinhard Denecke, Hans‐Peter Steinrück Angewandte Chemie International Edition, 2009
