TY - JOUR A1 - Schmidt, Stefan A1 - Göbel, Christoph A1 - Nebel, Janine A1 - Wiesmann, Thomas A1 - Hamel, Christian A1 - Reinsdorf, Arne A1 - Wolf, Dorit A1 - Gehrmann, Stefan A1 - Tenhumberg, Nils A1 - Muhler, Martin A1 - Kaluza, Stefan T1 - Recent Developments in the Conversion of Synthesis Gas to Short-Chain Alcohols over Cu-Co-Based Catalysts JF - Chemie Ingenieur Technik Y1 - 2018 U6 - https://doi.org/10.1002/cite.201800023 SN - 1522-2640 VL - 90 IS - 10 SP - 1465 EP - 1475 PB - Wiley ER - TY - JOUR A1 - Nebel, Janine A1 - Schmidt, Stefan A1 - Pan, Qiushi A1 - Lotz, Katrin A1 - Kaluza, Stefan A1 - Muhler, Martin T1 - On the role of cobalt carbidization in higher alcohol synthesis over hydrotalcite-based Co-Cu catalysts JF - Chinese Journal of Catalysis Y1 - 2019 U6 - https://doi.org/10.1016/S1872-2067(19)63344-9 SN - 1872-2067 N1 - The research project is funded by the Federal Ministry of Education and Research (Bundesministerium für Bildung und Forschung, BMBF, Verbundvorhaben Carbon2Chem®, FKZ: 03EK3041). VL - 40 IS - 11 SP - 1731 EP - 1740 PB - Elsevier ER - TY - JOUR A1 - Girod, Kai A1 - Lohmann, Heiko A1 - Schlüter, Stefan A1 - Kaluza, Stefan T1 - Methanol Synthesis with Steel-Mill Gases: Simulation and Practical Testing of Selected Gas Utilization Scenarios JF - Processes Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-26928 VL - 8 IS - 12 PB - MDPI ER - TY - JOUR A1 - Girod, Kai A1 - Breitkreuz, Klaas A1 - Henning, Torsten A1 - Lohmann, Heiko A1 - Kaluza, Stefan A1 - Schluter, Stefan T1 - Steel Mills as Syngas Source for Methanol Synthesis: Simulation and Practical Performance Investigations JF - Chemical Engineering Transactions N2 - In the present contribution, the utilization of steel-mill gases for an industrial methanol synthesis process is described. The focus of this work is on the influence of syngas compositions derived from steel-mill gases on an industrial Cu/ZnO/Al2O3 catalyst. Elevated CO2 and H2O concentrations seem to have an irreversible impact on the activity of the catalyst. In order to obtain realistic gas composition for the catalyst tests, a process simulation of the methanol synthesis was conducted. The calculated gas compositions at the reactor inlet were applied in a practical test in order to evaluate the catalyst stability under steel mill gas conditions. No noticeable deactivation was observed. KW - DOAJ Y1 - 2019 SN - 978-88-95608-71-6 U6 - https://doi.org/10.3303/CET1974080 SN - 2283-9216 VL - 74 SP - 475 EP - 480 PB - AIDIC ER - TY - JOUR A1 - Junge Puring, Kai A1 - Piontek, Stefan A1 - Smialkowski, Mathias A1 - Burfeind, Jens A1 - Kaluza, Stefan A1 - Doetsch, Christian A1 - Apfel, Ulf-Peter T1 - Simple Methods for the Preparation of Non-noble Metal Bulk-electrodes for Electrocatalytic Applications JF - Journal of visualized experiments : JoVE N2 - The rock material pentlandite with the composition Fe4.5Ni4.5S8 was synthesized via high temperature synthesis from the elements. The structure and composition of the material was characterized via powder X-ray diffraction (PXRD), Mössbauer spectroscopy (MB), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and energy dispersive X-ray spectroscopy (EDX). Two preparation methods of pentlandite bulk electrodes are presented. In the first approach a piece of synthetic pentlandite rock is directly contacted via a wire ferrule. The second approach utilizes pentlandite pellets, pressed from finely ground powder, which is immobilized in a Teflon casing. Both electrodes, whilst being prepared by an additive-free method, reveal high durability during electrocatalytic conversions in comparison to common drop-coating methods. We herein showcase the striking performance of such electrodes to accomplish the hydrogen evolution reaction (HER) and present a standardized method to evaluate the electrocatalytic performance by electrochemical and gas chromatographic methods. Furthermore, we report stability tests via potentiostatic methods at an overpotential of 0.6 V to explore the material limitations of the electrodes during electrolysis under industrial relevant conditions. Y1 - 2017 UR - http://www.ncbi.nlm.nih.gov/pubmed/28671654 U6 - https://doi.org/10.3791/56087 SN - 1940-087X IS - 124 PB - JoVE ER - TY - JOUR A1 - Schulzke, Tim A1 - Conrad, Stefan A1 - Kaluza, Stefan A1 - van Loo, Tom T1 - Upgrading of fast pyrolysis condensates via esterification with higher alcohols JF - Biomass and Bioenergy Y1 - 2017 U6 - https://doi.org/10.1016/j.biombioe.2017.05.010 SN - 0961-9534 N1 - Postprint ist veröffentlicht unter: http://publica.fraunhofer.de/dokumente/N-446003.html VL - 103 SP - 11 EP - 20 PB - Elsevier ER - TY - JOUR A1 - Weide, Philipp A1 - Schulz, Katharina A1 - Kaluza, Stefan A1 - Rohe, Markus A1 - Beranek, Radim A1 - Muhler, Martin T1 - Controlling the Photocorrosion of Zinc Sulfide Nanoparticles in Water by Doping with Chloride and Cobalt Ions JF - Langmuir Y1 - 2016 UR - http://www.ncbi.nlm.nih.gov/pubmed/27934521 U6 - https://doi.org/10.1021/acs.langmuir.6b03385 SN - 1520-5827 VL - 32 IS - 48 SP - 12641 EP - 12649 PB - ACS Publ. ER - TY - JOUR A1 - Wiesmann, Thomas A1 - Hamel, Christian A1 - Kaluza, Stefan T1 - Techniques to Remove Traces of Oxygen by Catalytic Conversion from Gas Mixtures JF - Chemie Ingenieur Technik Y1 - 2018 U6 - https://doi.org/10.1002/cite.201800022 SN - 1522-2640 VL - 90 IS - 10 SP - 1446 EP - 1452 PB - Wiley ER - TY - CHAP A1 - Kaluza, Stefan A1 - Muhler, Martin ED - Gaigneaux, E. M. ED - Devillers, M. ED - Hermans, S. ED - Jacobs, P. A. ED - Martens, J. A. ED - Ruiz, P. T1 - A novel continuous approach for the synthesis and characterization of pure and mixed metal oxide systems applied in heterogeneous catalysis T2 - Scientific Bases for the Preparation of Heterogeneous Catalysts Y1 - 2010 SN - 978-0-444-53601-3 U6 - https://doi.org/10.1016/S0167-2991(10)75027-8 VL - Studies in Surface Science and Catalysis, 175 SP - 217 EP - 220 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Kaluza, Stefan A1 - Schröter, Marie Katrin A1 - Naumann d'Alnoncourt, Raoul A1 - Reinecke, Thomas A1 - Muhler, Martin T1 - High Surface Area ZnO Nanoparticles via a Novel Continuous Precipitation Route JF - Advanced Functional Materials Y1 - 2008 U6 - https://doi.org/10.1002/adfm.200800457 SN - 1616-3028 N1 - The authors gratefully acknowledge fruitful discussions with Malte Behrens and Robert Schlögl, and financial support by the BMBF (Bundesministerium für Bildung und Forschung, project 01RI05028 “Entwicklung von Methanolsynthesekatalysatoren als Basis für nachhaltige Ressourcennutzung”). Supporting Information is available online from Wiley InterScience or from the author. VL - 18 IS - 22 SP - 3670 EP - 3677 ER - TY - JOUR A1 - Mei, Bastian A1 - Sánchez, Miguel D. A1 - Reinecke, Thomas A1 - Kaluza, Stefan A1 - Xia, Wei A1 - Muhler, Martin T1 - The synthesis of Nb-doped TiO2 nanoparticles by spray drying: an efficient and scalable method JF - Journal of Materials Chemistry Y1 - 2011 U6 - https://doi.org/10.1039/c1jm11431j SN - 1364-5501 VL - 21 IS - 32 SP - 11781 EP - 11790 PB - Royal Society of Chemistry (RSC) ER - TY - JOUR A1 - Peter, Maximilian A1 - Fichtl, Matthias B. A1 - Ruland, Holger A1 - Kaluza, Stefan A1 - Muhler, Martin A1 - Hinrichsen, Olaf T1 - Detailed kinetic modeling of methanol synthesis over a ternary copper catalyst JF - Chemical Engineering Journal Y1 - 2012 U6 - https://doi.org/10.1016/j.cej.2012.06.066 SN - 0009-2509 VL - 203 SP - 480 EP - 491 PB - Elsevier ER - TY - JOUR A1 - Schittkowski, Julian A1 - Ruland, Holger A1 - Laudenschleger, Daniel A1 - Girod, Kai A1 - Kähler, Kevin A1 - Kaluza, Stefan A1 - Muhler, Martin A1 - Schlögl, Robert T1 - Methanol Synthesis from Steel Mill Exhaust Gases: Challenges for the Industrial Cu/ZnO/Al 2 O 3 Catalyst JF - Chemie Ingenieur Technik Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-34526 SN - 1522-2640 N1 - We gratefully appreciate the support received from the Federal Ministry of Education and Research (Bundesministerium für Bildung und Forschung, BMBF, Verbundvorhaben Carbon2Chem®). VL - 90 IS - 10 SP - 1419 EP - 1429 PB - Wiley ER - TY - JOUR A1 - Titus, Juliane A1 - Kaluza, Stefan A1 - Marschall, Roland T1 - German Catalysis on an International Scale in Weimar JF - ChemCatChem Y1 - 2014 U6 - https://doi.org/10.1002/cctc.201402266 SN - 1867-3899 VL - 6 IS - 6 SP - 1523 EP - 1525 PB - Wiley ER - TY - JOUR A1 - Wiesmann, Thomas A1 - Youn Suh, Sung A1 - Kaluza, Stefan A1 - Lohmann, Heiko A1 - Zeidler‐Fandrich, Barbara T1 - Catalytic Oxygen Removal from Synthetic Coke Oven Gas: A Comparison of Sulfided CoMo/γ‐Al 2 O 3 and NiMo/γ‐Al 2 O 3 Catalysts with Pt/γ‐Al 2 O 3 as Benchmark Catalyst JF - Chemie Ingenieur Technik KW - DEAL Y1 - 2020 U6 - https://doi.org/10.1002/cite.202000067 N1 - The research project is funded by the Federal Ministry of Education and Research (Bundesministerium für Bildung und Forschung, BMBF, Verbundvorhaben Carbon2Chem®, FKZ: 03EK3040D). Open access funding enabled and organized by Projekt DEAL VL - 92 IS - 10 SP - 1533 EP - 1541 PB - Wiley ER - TY - JOUR A1 - Strucks, Peter A1 - Watermann, Clara A1 - Weber, Konradin A1 - Kaluza, Stefan T1 - Systematic Investigations of Vibrational and Fluid‐Mechanical Stability of Coated Monolithic Catalysts JF - Chemie Ingenieur Technik N2 - Heterogeneous catalysts usually consist of porous, inorganic materials. Especially in the mobile application, e.g., in exhaust gas catalysis as a part of the gas line of an engine, there are loads due to vibrations and high gas velocities. It can be assumed that physical stress will lead to a loss of the catalytically active coating. The present contribution describes experimental setups and methods for a systematic and reproducible investigation of the main influences to the mass loss due to vibrational and fluid‐mechanical stress caused by particle‐free gas flows. KW - Design of experiments KW - Extruded catalysts KW - Mechanical stability KW - Luftreinhaltung Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-28930 SN - 1522-2640 VL - 93 IS - 5 SP - 1 EP - 6 PB - Wiley ER - TY - JOUR A1 - Falling, Luisa A1 - Kaluza, Stefan A1 - Strucks, Peter T1 - A Short Review on Ni-Catalyzed Methanation of CO²: Reaction Mechanism, Catalyst Deactivation, Dynamic Operation JF - Chemie Ingenieur Technik N2 - Today, the use of renewable energies and recycling of climate-changing gases are increasingly important. In this context,coupling of methanation with small, decentralized CO2sources such as biogas plants provides one possibility. However,fluctuating availability of renewables for hydrogen production in combination with small storage volumes result in anenhanced demand for dynamic process operation. This leads to new research challenges with respect to the required cata-lysts and the overall process design. To draw reliable conclusions about the catalytic performance under dynamic processoperation, the mechanism of the methanation reaction as well as typical deactivation procedures of the catalyst appliedunder steady-state conditions have to be reviewed thoroughly. KW - Power-to-gas KW - Ni catalysts KW - Dynamic operation KW - Deactivation KW - CO2Methanation Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-32134 SN - 1522-2640 VL - 93 SP - 1526 EP - 1536 PB - Wiley ER - TY - CHAP A1 - Anton, Johan A1 - Nebel, Janine A1 - Froese, Christian A1 - Kleinschmidt, Ralph A1 - Quandt, Thomas A1 - Ruland, Holger A1 - Kaluza, Stefan A1 - Muhler, Martin ED - Ernst, Stefan T1 - Higher alcohol synthesis over Na-modified Co-Cu catalysts: Co2C formation and effect of surface composition T2 - Preprints of the DGMK-Conference "Synthesis Gas Chemistry", October 7 - 9, 2015, Dresden N2 - Cu–Co-based model catalysts were prepared by a sophisticated alkali-free synthesis method and tested in the conversion of synthesis gas to higher alcohols. MoO3-coated alumina was used as the support, providing both high specific surface area and strongly interacting sites for the deposition of the active metals. A bulk Cu/Co ratio of ~2 was found to be most suitable in terms of activity and product distribution. Surface enrichment of Mo for all samples was observed by XPS, which significantly influenced the performance of the catalysts. Mo was found to be both a structural and a chemical promoter. Strong metal–support interactions were further achieved by modification of alumina with magnesia. With 12 wt% Mg incorporated, the catalysts showed 40% total oxygenate selectivity including 11% selectivity to ethanol. Y1 - 2015 SN - 978-3-941721-56-2 VL - DGMK Tagungsbericht, 2015,2 PB - DGMK CY - Hamburg ER - TY - JOUR A1 - Anton, Johan A1 - Nebel, Janine A1 - Song, Huiqing A1 - Froese, Christian A1 - Weide, Philipp A1 - Ruland, Holger A1 - Muhler, Martin A1 - Kaluza, Stefan T1 - Structure–activity relationships of Co-modified Cu/ZnO/Al2O3 catalysts applied in the synthesis of higher alcohols from synthesis gas JF - Applied Catalysis A: General Y1 - 2015 U6 - https://doi.org/10.1016/j.apcata.2015.07.002 SN - 0926-860X VL - 505 SP - 326 EP - 333 PB - Elsevier ER - TY - JOUR A1 - Anton, Johan A1 - Nebel, Janine A1 - Göbel, Christoph A1 - Gabrysch, Thomas A1 - Song, Huiqing A1 - Froese, Christian A1 - Ruland, Holger A1 - Muhler, Martin A1 - Kaluza, Stefan T1 - CO Hydrogenation to Higher Alcohols over Cu–Co-Based Catalysts Derived from Hydrotalcite-Type Precursors JF - Topics in Catalysis Y1 - 2016 UR - https://doi.org/10.1007/s11244-016-0663-2 U6 - https://doi.org/10.1007/s11244-016-0663-2 VL - 59 IS - 15-16 SP - 1361 EP - 1370 PB - Springer Nature ER - TY - JOUR A1 - Anton, Johan A1 - Nebel, Janine A1 - Song, Huiqing A1 - Froese, Christian A1 - Weide, Philipp A1 - Ruland, Holger A1 - Muhler, Martin A1 - Kaluza, Stefan T1 - The effect of sodium on the structure–activity relationships of cobalt-modified Cu/ZnO/Al2O3 catalysts applied in the hydrogenation of carbon monoxide to higher alcohols JF - Journal of Catalysis Y1 - 2016 U6 - https://doi.org/10.1016/j.jcat.2015.12.016 SN - 0021-9517 VL - 335 SP - 175 EP - 186 PB - Elsevier ER - TY - JOUR A1 - Anton, Johan A1 - Ruland, Holger A1 - Kaluza, Stefan A1 - Muhler, Martin T1 - Fast and Reproducible Testing of Cu–Co-Based Catalysts Applied in the Conversion of Synthesis Gas to Ethanol and Higher Alcohols JF - Catalysis Letters Y1 - 2015 U6 - https://doi.org/10.1007/s10562-015-1543-2 N1 - The work was part of the project “Bioethanol from synthesis gas—BETSY”, funded by the Ministry for Economy, Energy, Building, Habitation and Transportation of Northrhine-Westphalia within the program Ziel2.NRW financed by the European Union through the European regional development fund ERDF. VL - 145 IS - 7 SP - 1374 EP - 1381 PB - Springer ER - TY - JOUR A1 - Bordoloi, Ankur A1 - Sanchez, Miguel A1 - Noei, Heshmat A1 - Kaluza, Stefan A1 - Großmann, Dennis A1 - Wang, Yuemin A1 - Grünert, Wolfgang A1 - Muhler, Martin T1 - Catalytic Behaviour of Mesoporous Cobalt-Aluminum Oxides for CO Oxidation JF - Journal of Catalysts Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-34344 SN - 2314-5110 SP - 1 EP - 9 PB - Hindawi ER - TY - JOUR A1 - Boz, İsmail A1 - Kaluza, Stefan A1 - Boroğlu, Mehtap Şafak A1 - Muhler, Martin T1 - Synthesis of high surface area ZnO powder by continuous precipitation JF - Materials Research Bulletin Y1 - 2012 U6 - https://doi.org/10.1016/j.materresbull.2012.02.005 SN - 1873-4227 VL - 47 IS - 5 SP - 1185 EP - 1190 PB - Elsevier ER - TY - JOUR A1 - Engel, Rebecca V. A1 - Kaluza, Stefan A1 - Oezaslan, Mehtap A1 - Peitz, Stephan T1 - German Catalysis Meeting - 50 Years and as Young as Ever JF - ChemCatChem Y1 - 2017 U6 - https://doi.org/10.1002/cctc.201700683 SN - 1867-3899 VL - 9 IS - 11 SP - 2018 EP - 2020 PB - Wiley ER - TY - JOUR A1 - Engeldahl, Barthel A1 - Özaslan, Mehtap A1 - Marschall, Roland A1 - Rose, Marcus A1 - Kaluza, Stefan A1 - Titus, Juliane A1 - Sprung, Christoph T1 - Weimar 2015: Catalysing Tomorrow’s Solutions JF - ChemCatChem Y1 - 2015 U6 - https://doi.org/10.1002/cctc.201500435 SN - 1867-3899 VL - 7 IS - 12 SP - 1794 EP - 1796 PB - Wiley ER - TY - JOUR A1 - Girod, Kai A1 - Breitkreuz, Klaas A1 - Gerstner, Andrea A1 - Marzi, Thomas A1 - Schulzke, Tim A1 - Kaluza, Stefan T1 - Close‐to‐Practice Investigations of Heterogeneously Catalyzed Syngas Conversions in Slurry and Fixed‐Bed Reactor Systems JF - Chemie Ingenieur Technik Y1 - 2018 U6 - https://doi.org/10.1002/cite.201700143 SN - 1522-2640 VL - 90 IS - 5 SP - 690 EP - 695 PB - Wiley ER - TY - JOUR A1 - Girod, Kai A1 - Lohmann, Heiko A1 - Kaluza, Stefan T1 - Methanol Synthesis with Steel Mill Gases: Performance Investigations in an On‐Site Technical Center JF - Chemie Ingenieur Technik KW - DEAL Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-34409 SN - 1522-2640 N1 - he investigations within the scope of the project Carbon2Chem® are funded by the German Federal Ministry of Education and Research (BMBF; support code: 03EK3039F). We also thank our project partners in the Carbon2Chem subproject L2 (methanol synthesis) for the trustful cooperation. Open access funding enabled and organized by Projekt DEAL. VL - 93 IS - 5 SP - 850 EP - 855 PB - Wiley ER - TY - CHAP A1 - Hamel, Christian A1 - Kaluza, Stefan A1 - Unger, Christoph ED - Ernst, Stefan T1 - Catalytic tar reforming of biomass-derived synthesis gas: Influence of the catalyst, gas composition and sulfur poisoning T2 - Preprints of the DGMK-Conference "Synthesis Gas Chemistry",October 7 - 9, 2015, Dresden Y1 - 2015 SN - 978-3-941721-56-2 VL - DGMK Tagungsbericht, 2015,2 SP - 139 EP - 146 PB - DGMK CY - Hamburg ER - TY - JOUR A1 - Heeskens, Denise A1 - Aghaei, Pedram A1 - Kaluza, Stefan A1 - Strunk, Jennifer A1 - Muhler, Martin T1 - Selective oxidation of ethanol in the liquid phase over Au/TiO 2 JF - physica status solidi (b) Y1 - 2013 U6 - https://doi.org/10.1002/pssb.201248440 SN - 1521-3951 VL - 250 IS - 6 SP - 1107 EP - 1118 PB - Wiley ER - TY - JOUR A1 - Kaluza, Stefan A1 - Behrens, Malte A1 - Schiefenhövel, Nora A1 - Kniep, Benjamin A1 - Fischer, Richard A1 - Schlögl, Robert A1 - Muhler, Martin T1 - A Novel Synthesis Route for Cu/ZnO/Al2O3 Catalysts used in Methanol Synthesis: Combining Continuous Consecutive Precipitation with Continuous Aging of the Precipitate JF - ChemCatChem Y1 - 2011 U6 - https://doi.org/10.1002/cctc.201000329 SN - 1867-3899 VL - 3 IS - 1 SP - 189 EP - 199 PB - Wiley ER - TY - JOUR A1 - Kaluza, Stefan A1 - Muhler, Martin T1 - On the precipitation mechanism and the role of the post-precipitation steps during the synthesis of binary ZnO–Al2O3 composites with high specific surface area JF - Journal of Materials Chemistry KW - FBMV Y1 - 2009 U6 - https://doi.org/10.1039/b902004g SN - 1364-5501 VL - 19 IS - 23 SP - 3914 EP - 3922 PB - Royal Society of Chemistry (RSC) ER - TY - JOUR A1 - Kaluza, Stefan A1 - Muhler, Martin T1 - On the Role of Aging, Washing, and Drying in the Synthesis of Polycrystalline Zinc Oxide by Precipitation: Combining Fast Continuous Mixing, Spray Drying and Freeze Drying to Unravel the Solid-State Transformations of the Precipitate JF - Catalysis Letters Y1 - 2009 UR - 1572-879X U6 - https://doi.org/10.1007/s10562-008-9818-5 N1 - The authors gratefully acknowledge fruitful discussions with Malte Behrens and Robert Schlögl, and the financial support by the BMBF (Bundesministerium für Bildung und Forschung) within the scope of the project 01RI05028 “Entwicklung von Methanolsynthesekatalysatoren als Basis für nachhaltige Ressourcennutzung” VL - 129 IS - 3-4 SP - 287 EP - 292 PB - Springer ER - TY - JOUR A1 - Failing, Luisa A1 - Kaluza, Stefan A1 - Strucks, Peter T1 - Catalytic CO2 methanation: Providing optimal test conditions for kinetic investigations JF - Chemie Ingenieur Technik N2 - In the context of using renewable energies and recycling climate-changing gases, methanation of CO2 provides one possibility. However, volatile availability of renewable energies for hydrogen production and fluctuating CO2streams from different sources lead to enhanced demand in investigating the influence of dynamic process operation on the catalyst performance, including detailed kinetic characterization. Reliable kinetic measurements require isothermal temperature control and absence of macrokinetic diffusion limitations. Both were investigated in this work while the determination of steady-state kinetic parameters is part of ongoing studies. Furthermore, a detailed analysis with respect to the long-term-stability of the nickel-based catalyst was performed KW - CO2 methanation KW - Kinetics KW - Long-term stability KW - Ni catalyst KW - Power-to-Gas Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-40026 SN - 1522-2640 VL - 95 IS - 5 SP - 749 EP - 753 PB - Wiley ER - TY - JOUR A1 - Winter, Franziska Luise A1 - Diehl, Patrick A1 - Telaar, Pascal A1 - Watermann, Clara Maria A1 - Kaluza, Stefan A1 - Muhler, Martin A1 - Apfel, Ulf-Peter A1 - Zeidler-Fandrich, Barbara T1 - Influence of the catalyst precursor for cobalt on activated carbon applied in ammonia decomposition JF - Catalysis Today N2 - Ammonia is a key compound for storing and transporting green hydrogen. However, the efficient release of stored hydrogen through thermocatalytic ammonia decomposition is achievable only at temperatures around 600 °C, particularly with non-noble metal-based catalysts, which prove to be both ecologically and economically more feasible. In this study, electrically conductive activated carbon was selected as the catalyst support, chosen specifically for its suitability in achieving more energy-efficient direct reactor heating through the ohmic resistance of the catalysts. Cobalt salts were wet impregnated on activated carbon investigating the influence of different precursors (cobalt nitrate and cobalt acetate) and pyrolysis temperatures (400 °C and 600 °C) under N2 flow on the cobalt particle size and the incorporation of cobalt into the carbon matrix. TEM imaging and CO-chemisorption revealed well dispersed cobalt particles with sizes below 10 nm for the catalysts synthesized from the cobalt nitrate precursor. On the other hand, cobalt acetate led to about nine times larger Co agglomerates, which were partially detached from the carbon matrix. Moreover, this substantial difference in the Co particle size results in a significantly higher ammonia conversion for cobalt nitrate-based catalysts, achieving 94 % of ammonia conversion at 600 °C. Furthermore, the long-term stability test of the cobalt nitrate-based catalyst resulted in a slight deactivation of only 2 % ammonia conversion at 500 °C. KW - Katalyse KW - Ammoniak KW - Grüner Wasserstoff KW - Ammonia decomposition KW - Carbon supported cobalt KW - Synthesis design KW - Cobalt acetate KW - Cobalt nitrate KW - Resistance heating Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-46600 SN - 0920-5861 VL - 429 PB - Elsevier ER - TY - CHAP A1 - Wacht, Anika A1 - Kaluza, Stefan A1 - Fleiger, Philipp ED - Leipzig, Konrad von ED - Sacks, Natasha ED - Mc Clelland, Michelle T1 - Carbon Capture and Utilization in Cement Industry—Aspects of the Production of E-Fuels by Upcycling Carbon Dioxide T2 - Smart, Sustainable Manufacturing in an Ever-Changing World: Proceedings of International Conference on Competitive Manufacturing (COMA ’22) KW - Carbon dioxide capture and utilization KW - Synthetischer Kraftstoff KW - Upcycling KW - Kreislaufwirtschaft KW - Zementindustrie KW - Kohlendioxid Y1 - 2023 SN - 9783031156014 U6 - https://doi.org/10.1007/978-3-031-15602-1_44 SN - 2194-0525 SP - 603 EP - 612 PB - Springer Nature CY - Cham ER - TY - JOUR A1 - Greuel, Marc A1 - Watermann, Clara Maria A1 - Lohmann, Heiko A1 - Kaluza, Stefan A1 - Apfel, Ulf-Peter A1 - Zeidler-Fandrich, Barbara T1 - The conversion of ethanol over 3d-metal saponite-like smectites JF - Materials Advances N2 - The replacement of fossil fuel processes with renewable pathways is critical to circumvent climate change and environmental risks. A process of interest is the production of 1,3-butadiene (BD), which is primarily derived as a by-product of naphtha steam cracking. A sustainable alternative path involves converting renewable ethanol to BD via the Lebedev process, which requires a catalyst with balanced redox, acidic, and basic sites. Due to the necessity of a multifunctional catalyst, existing materials for this reaction are either comprised of catalyst mixtures or supported catalysts. In this study, we introduce a bulk material, saponite, containing M–O–Si sites, which combine required catalytic sites for the ethanol to BD (ETB) reaction in one material. The product composition in ethanol conversion were strongly dependent on the type of 3d-metal used, while no conclusive correlation between surface properties, conversion, and product composition was observed. Herein, using V-Sap*, we achieved an ethene productivity of 448 gethene kgcat−1 h−1 (74%) at 573.15 K. High acetaldehyde productivity was maintained with Cu-Sap* (466 gAcA kgcat−1 h−1, 49%) at 573.15 K and Zn-Sap (528 gAcA kgcat−1 h−1, 55%) at 723.15 K. Mg-Sap primarily produced ethene but also yielded 10 gBD kgcat−1 h−1 BD at 723.15 K. Higher BD outputs were observed with Ni-Sap (31 gBD kgcat−1 h−1 at 523.15 K) and Mn-Sap* (51 gBD kgcat−1 h−1 at 723.15 K). This underscores the potential of saponite-based materials for flexible product outputs in ethanol conversion, influenced by the choice of integrated 3d-metal. KW - Butadien KW - Katalyse KW - Material Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-52973 SN - 2633-5409 IS - 6 SP - 2885 EP - 2898 PB - Royal Society of Chemistry ER - TY - RPRT A1 - Failing, Luisa A1 - Kaluza, Stefan A1 - Strucks, Peter T1 - Power2Gas - Katalytische Methanisierung von CO₂ als Baustein einer erfolgreichen Energie- und Rohstoffwende N2 - Die katalytische Methanisierung von Kohlendioxid (CO2) mit Hilfe von elektrolytisch erzeugtem Wasserstoff (H2) aus erneuerbaren Energiequellen kann einen wichtigen Beitrag zur Reduktion von CO2-Emissionen leisten. Aufgrund einer immer stärker fluktuierenden Energie- und Rohstoffbereitstellung spielt die Möglichkeit einer flexiblen, dynamischen Betriebsweise eine zunehmend große Rolle für zukünftige Technologien. Dies bedingt auch im Fall der katalytischen Methanisierung umfangreiche Untersuchungen, um zu ermitteln, inwieweit eine dynamische Fahrweise Auswirkungen auf Prozess und Katalysator besitzt. An diesem Punkt setzte das HiFF-Projekt Power2Gas an. So wurden verschiedene nickelbasierte Katalysatorsysteme synthetisiert, wobei sich der via Imprägnierung hergestellte Ni/Al2O3-Katalysator sowohl aufgrund seiner guten Leistung als auch der praktikablen und reproduzierbaren Herstellung als geeignetes Benchmark-System für weitere Untersuchungen - vor allem im kinetischen Bereich - erwies. Während umfassender Parametervariationen wurden kinetische Datensätze im stationären Zustand bestimmt, die zur Modellierung der katalysierten CO2-Methanisierung verwendet werden können. Darüber hinaus wurden in ausgewählten Versuchsreihen die isotherme Temperaturkontrolle und eine ausreichende Langzeitstabilität sichergestellt sowie makrokinetische Diffusionsbeschränkungen ausgeschlossen. Die Ergebnisse wurden in einer peer-review-Publikation veröffentlicht und auf zwei Konferenzen präsentiert. Sie waren zudem die Basis für eine erfolgreiche Masterarbeit und flossen in die Antragstellung im Rahmen des DFG-Programms „Großgeräteaktion für Hochschulen für Angewandte Wissenschaften“ ein. N2 - The catalytic methanation of carbon dioxide (CO2) using electrolytically produced hydrogen (H2) from renewable energy sources represents a potential option for reducing CO2 emissions. Due to an increasingly fluctuating availability of energy and raw materials, the need for flexible, dynamic operation is becoming ever more crucial for future technologies. In the case of catalytic methanation, this also requires further investigations to determine the impact of dynamic operation on the process and catalysts. This is where the HiFF Power2Gas project comes in. Various nickel-based catalyst systems were synthesized. The Ni/Al2O3 catalyst produced via impregnation was identified as a suitable benchmark system for further investigations - particularly in the kinetic range - due to its good performance as well as its simple and reproducible synthesis. By thorough parameter variation, kinetic data sets were determined in steady state, which can be used to model catalyzed CO2 methanation. In addition, isothermal temperature control and long-term stability were ensured in a series of selected experiments, while macro-kinetic diffusion limitations could be ruled out. The results were published in a peer-reviewed publication and presented at two conferences. They were also fundamental for a successful master's thesis and were used in an application for the DFG program "Großgeräteaktion für Hochschulen für Angewandte Wissenschaften". T3 - Berichte zu HSD-intern geförderten Forschungsprojekten - 4 KW - Dekarbonisierung KW - Dynamische Betriebsweise KW - Nickel-Katalysator KW - Deaktivierung KW - Power-to-X KW - CO₂ Methanisierung Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-45143 SN - 2625-3690 CY - Düsseldorf ER - TY - BOOK A1 - Marzi, Thomas A1 - Deerberg, Görge A1 - Dötsch, Christian A1 - Grevé, Anna A1 - Hiebel, Markus A1 - Kaluza, Stefan A1 - Knappertsbusch, Volker A1 - Maga, Daniel A1 - Müller, Torsten A1 - Pflaum, Hartmut A1 - Pohlig, Astrid A1 - Renner, Manfred A1 - Seifert, Ulrich A1 - Stießel, Sebastian A1 - Unger, Christoph A1 - Wack, Thorsten A1 - Weidner, Eckhard T1 - Kohlendioxid, Biomasse und Regenerativer Strom - Ressourcen einer neuen Kohlenstoffwirtschaft? Y1 - 2017 SN - 978-3-87468-358-6 U6 - https://doi.org/10.24406/UMSICHT-N-473349 VL - Umsicht-Diskurs IS - 1 PB - Fraunhofer-Institut für Umwelt-, Sicherheit- und Energietechnik CY - Oberhausen ER -