TY - GEN A1 - Matthies, Ellen A1 - Beer, Katrin A1 - Böcher, Michael A1 - Sundmacher, Kai A1 - König-Mattern, Laura A1 - Arlinghaus, Julia A1 - Blöbaum, Anke A1 - Jaeger-Erben, Melanie A1 - Schmidt, Karolin T1 - Framework conditions for the transformation toward a sustainable carbon-based chemical industry – A critical review of existing and potential contributions from the social sciences T2 - Journal of Cleaner Production Y1 - 2024 U6 - https://doi.org/10.1016/j.jclepro.2024.143279 SN - 0959-6526 VL - 470 (2024) SP - 1 EP - 13 PB - Elsevier BV ER - TY - GEN A1 - Tschammer, Rudi A1 - Buß, Lars A1 - Pożarowska, Emilia A1 - Morales, Carlos A1 - Senanayake, Sanjaya D. A1 - Prieto, Mauricio J. A1 - Tănase, Liviu C. A1 - de Souza Caldas, Lucas A1 - Tiwari, Aarti A1 - Schmidt, Thomas A1 - Niño, Miguel A. A1 - Foerster, Michael A1 - Falta, Jens A1 - Flege, Jan Ingo T1 - High-temperature growth of CeOx on Au(111) and behavior under reducing and oxidizing conditions T2 - The journal of physical chemistry C N2 - Inverse oxide–metal model catalysts can show superior activity and selectivity compared with the traditional supported metal–oxide architecture, commonly attributed to the synergistic overlayer–support interaction. We have investigated the growth and redox properties of ceria nanoislands grown on Au(111) between 700 and 890 °C, which yields the CeO2–Au(111) model catalyst system. We have observed a distinct correlation between deposition temperature, structural order, and oxide composition through low-energy electron microscopy, low-energy electron diffraction, intensity–voltage curves, and X-ray absorption spectroscopy. Improved structural order and thermal stability of the oxide have been achieved by increasing the oxygen chemical potential at the substrate surface using reactive oxygen (O/O2) instead of molecular O2 during growth. In situ characterization under reducing (H2) and oxidizing atmospheres (O2, CO2) indicates an irreversible loss of structural order and redox activity at high reduction temperatures, while moderate temperatures result in partial decomposition of the ceria nanoislands (Ce3+/Ce4+) to metallic cerium (Ce0). The weak interaction between Au(111) and CeOx would facilitate its reduction to the Ce0 metallic state, especially considering the comparatively strong interaction between Ce0 and Au0. Besides, the higher reactivity of atomic oxygen promotes a stronger interaction between the gold and oxide islands during the nucleation process, explaining the improved stability. Thus, we propose that by driving the nucleation and growth of the ceria/Au system in a highly oxidizing regime, novel chemical properties can be obtained. KW - Inverse oxide-metal model catalysts KW - Ceria nanoislands KW - Growth KW - Redox properties KW - Low-energy electron microscopy (LEEM) KW - Low-energy electron diffraction (LEED) KW - Intensity–voltage curves KW - X-ray absorption spectroscopy (XAS) Y1 - 2025 U6 - https://doi.org/10.1021/acs.jpcc.4c08072 SN - 1932-7447 VL - 129 IS - 7 SP - 3583 EP - 3594 PB - American Chemical Society (ACS) CY - Washington, DC ER - TY - GEN A1 - Veldkamp, Edzo A1 - Schmidt, Marcus A1 - Markwitz, Christian A1 - Beule, Lukas A1 - Beuschel, René A1 - Biertümpfel, Andrea A1 - Bischel, Xenia A1 - Duan, Xiaohong A1 - Gerjets, Rowena A1 - Göbel, Leonie A1 - Graß, Rüdiger A1 - Guerra, Victor A1 - Heinlein, Florian A1 - Komainda, Martin A1 - Langhof, Maren A1 - Luo, Jie A1 - Potthoff, Martin A1 - Ramshorst, Justus G. V. van A1 - Rudolf, Carolin A1 - Seserman, Diana-Maria A1 - Shao, Guodong A1 - Siebicke, Lukas A1 - Svoboda, Nikolai A1 - Swieter, Anita A1 - Carminati, Andrea A1 - Freese, Dirk A1 - Graf, Torsten A1 - Greef, Jörg M. A1 - Isselstein, Johannes A1 - Jansen, Martin A1 - Karlovsky, Petr A1 - Knohl, Alexander A1 - Lamersdorf, Norbert A1 - Priesack, Eckart A1 - Wachendorf, Christine A1 - Wachendorf, Michael A1 - Corre, Marife D. T1 - Multifunctionality of temperate alley-cropping agroforestry outperforms open cropland and grassland T2 - Communications Earth & Environment N2 - AbstractIntensively managed open croplands are highly productive but often have deleterious environmental impacts. Temperate agroforestry potentially improves ecosystem functions, although comprehensive analysis is lacking. Here, we measured primary data on 47 indicators of seven ecosystem functions in croplands and 16 indicators of four ecosystem functions in grasslands to assess how alley-cropping agroforestry performs compared to open cropland and grassland. Carbon sequestration, habitat for soil biological activity, and wind erosion resistance improved for cropland agroforestry (P ≤ 0.03) whereas only carbon sequestration improved for grassland agroforestry (P < 0.01). In cropland agroforestry, soil nutrient cycling, soil greenhouse gas abatement, and water regulation did not improve, due to customary high fertilization rates. Alley-cropping agroforestry increased multifunctionality, compared to open croplands. To ameliorate the environmental benefits of agroforestry, more efficient use of nutrients is required. Financial incentives should focus on conversion of open croplands to alley-cropping agroforestry and incorporate fertilizer management. Y1 - 2023 U6 - https://doi.org/10.1038/s43247-023-00680-1 SN - 2662-4435 VL - 4 IS - 1 PB - Springer Science and Business Media LLC ER - TY - GEN A1 - Lucke, Bernhard A1 - Schmidt, Michael A1 - Al-Saad, Ziad A1 - Hüttl, Reinhard F. A1 - Bens, Oliver T1 - The abandonment of the Decapolis region in Northern Jordan - forced by environmental change? T2 - Quaternary International Y1 - 2005 SN - 1040-6182 VL - 135 IS - 1 SP - 65 EP - 81 ER - TY - GEN A1 - Balas, Johannes A1 - Urbank, Christian A1 - Kaden, Peter A1 - Patzschke, Michael A1 - März, Juliane A1 - Kvashnina, Kristina O. A1 - Schmidt, Moritz A1 - Stumpf, Thorsten A1 - Gericke, Robert T1 - Bonding trends in pyridine-2-thiolato complexes of tetravalent actinides T2 - Inorganic chemistry N2 - Complexes of tetravalent actinides (An: Th, U, Np, Pu) with the bidentate (N,S)-donor ligand pyridine-2-thiolate (2-PyS, PyS−) were synthesized in 1:4 or 1:5 ratios. This includes the first structurally characterized Np complex with (N,S)-donor ligands, filling a notable gap in An coordination chemistry. An improved synthetic approach with PyS–SiMe3 enabled efficient formation of the 1:4 complexes in THF as coordinating solvent. The compounds were comprehensively characterized in solution and in solid phase, supported by quantum chemical calculations. Experimental and theoretical results show matching trends in the binding behavior of AnIV. The covalent bond contributions in An–N and An–S bonding increase along the series of An from Th to Pu. The bonds to the soft sulfur donors consistently have the highest covalent contributions with a remarkably high percentage for Pu–S (IQA analysis: >34%) over the harder N donors or An–O bonds of coordinating THF. High-resolution X-ray absorption and infrared spectroscopy indicate similar electronic and structural properties across AnIV complexes, while SQUID magnetometry uncovered significant differences in magnetic behavior at low temperatures depending on the complex compositions. This work advances the understanding of An-ligand bonding, emphasizing covalency and electronic structures, and expands fundamental insights into An chemistry. KW - Actinides KW - Single-crystal X-ray diffraction KW - Bonding trends KW - HERFD-XANES KW - SQUID Y1 - 2025 U6 - https://doi.org/10.1021/acs.inorgchem.5c03369 SN - 1520-510X VL - 64 IS - 44 SP - 21919 EP - 21931 PB - American Chemical Society CY - Washington, DC ER - TY - RPRT A1 - Schmidt, Peer A1 - Giese, Marie A1 - Heinemann, Robert A1 - Nawdiyal, Amruta A1 - Knorr, Monika A1 - Breitkopf, Cornelia A1 - Schneegans, Marcel Felix A1 - Pinnau, Sebastian A1 - Lorenz, Tommy A1 - Mickoleit, Erik A1 - to Baben, Moritz A1 - Keuter, Philipp A1 - Müller, Michael A1 - Sergeev, Dmitry A1 - Ewaznezhad Fard, Darya A1 - Morsa, Amedeo A1 - Rhys, Dominic Jacob A1 - Yazhenskikh, Elena T1 - PCM-Screening-2 : Evaluierung eutektischer Gemische für den Einsatz als PCM : thermodynamische Modellierung und experimentelle Methoden - 2 T2 - Deutsche Forschungsberichte N2 - Durch den Einsatz von Wärme- und Kältespeichern in Gebäuden, Industrieanlagen und Kraftwerken können Lastschwankungen reduziert und die Anlageneffizienz verbessert werden. Latentwärmespeicher (PCM) ermöglichen durch Ausnutzung einer fest-flüssig Phasenumwandlung hohe Speicherdichten bei geringen Temperaturdifferenzen. Die Verfügbarkeit geeigneter und kostengünstiger PCM’s ist derzeit noch eingeschränkt. Ein Screening geeigneter Stoffsysteme zur Bildung multinärer Eutektika durch thermodynamische Modellierung der Phasengleichgewichte erlaubt fundierte Vorhersagen zur Zusammensetzung eutektischer Gemische, ihren Schmelztemperaturen und -enthalpien. Auf Basis der Literatur, umfangreicher experimenteller Untersuchungen und Simulationen wurde im Projekt eine im Temperaturbereich nicht eingeschränkte thermochemische Datenbank für das komplexe Stoffsystem Na+, K+, Ca2+, Mg2+ // Cl−, NO3−, SO4_2−, CO3_2− // H2O geschaffen, die eine Auswahl neuer PCM mit optimalen thermodynamischen Eigenschaften für spezifische Prozessanforderungen auf Basis von in Deutschland in großen Mengen verfügbaren, preiswerten Rohstoffen ermöglicht. Weiterhin wurde ein CalPhaD-basiertes Viskositätsmodell, ein Screening-Verfahren inkl. Webserver und intuitive Visualisierungsmöglichkeiten hochkomponentiger Systeme entwickelt. Mittels eines Screenings erfolgte eine Vorauswahl von potentiell als PCM geeigneten Gemischen, die umfangreich charakterisiert wurden. Auf Basis der vielversprechenden Speicherdichten und der niedrigen Materialkosten wird erwartet, dass ein oder mehrere dieser identifizierten PCMs in die Anwendung als thermische Speicher gebracht werden können. N2 - The use of heat and cold storage systems in buildings, industrial plants, and power stations can reduce load fluctuations and improve plant efficiency. Latent heat storage systems (phase change materials - PCM) enable high storage densities with low temperature differences by exploiting a solid-liquid phase transition. The availability of suitable and cost-effective PCMs is currently still limited. Screening suitable material systems for the formation of multinary eutectics through thermodynamic modeling of phase equilibria allows well-founded predictions to be made about the composition of eutectic mixtures, their melting temperatures, and enthalpies. Based on the literature, extensive experimental investigations, and simulations, the project created a thermochemical database for the complex material system Na+, K+, Ca2+, Mg2+ // Cl−, NO3−, SO4_2−, CO3_2− // H2O was created, which enables the selection of new PCMs with optimal thermodynamic properties for specific process requirements based on inexpensive raw materials available in large quantities in Germany. Furthermore, a CalPhaD-based viscosity model, a screening procedure including a web server, and intuitive visualization options for highly component systems were developed. A screening process was used to preselect mixtures potentially suitable as PCMs, which were then extensively characterized. Based on the promising storage densities and low material costs, it is expected that one or more of these identified PCMs can be put into application as thermal storage. KW - PCM KW - Latenwärmespeicher KW - Eutektische Gemische KW - Thermodynamische Daten KW - Thermodynamische Modellierung KW - Anorganische Salzhydrate KW - Anorganische Salze Y1 - 2026 UR - https://oa.tib.eu/renate/handle/123456789/29435 U6 - https://doi.org/10.34657/28504 ER - TY - GEN A1 - Bölte, Jens-Henning A1 - Utgenannt, Stephan A1 - Schmidt, Max A1 - Klepel, Olaf A1 - Bron, Michael A1 - Rokicińska, Anna A1 - Jarczewski, Sebastian A1 - Kuśtrowski, Piotr T1 - S-doped and N+S-co-doped carbon catalysts in redox reactions T2 - Microporous and mesoporous materials N2 - In this contribution, the effects of heteroatom doping of porous carbon materials with S and N on their ability to catalyze redox-reactions involving the activation of molecular oxygen were investigated. For this purpose, a library of in total 54 undoped, S-doped and N + S-co-doped porous carbons was obtained via a template-based synthesis procedure using mesoporous silica gel as the template. To understand the influence of S on the properties of the doped carbons three different S-containing precursors, namely dimethyl sulfoxide (DMSO), p-toluene sulfonic acid and thiophene, were used. In order to investigate possible synergistic effects of S- and N-co-doping, urea was employed as the sole N-containing precursor. The obtained carbon catalysts were characterized by selected methods such as N2-physisorption at 77 K, X-ray diffraction (XRD), Raman spectroscopy, elemental analysis and X-ray photoelectron spectroscopy (XPS). Each carbon catalyst was tested in the oxidation of sulfurous acid (OSA) to sulfuric acid, the electrochemical oxygen reduction (ORR) and the oxidative dehydrogenation (ODH) of ethylbenzene. Owing to the similar textural and structural properties achieved through template-based synthesis of the carbon catalyst library, the results of the catalytic redox-reactions could directly be related to the respective heteroatom dopant. The observed trends indicate that in these redox-reactions S-species behave somewhat similar to O-species bound on the carbon surface. Furthermore, it can be shown that N + S co-doping rather combines the positive and negative effects of the individual dopants on the activity, than creating a synergistic effect that surpasses the individual contribution. KW - Porous carbon KW - Heteroatom-doping KW - Redox-reactions KW - Catalysis KW - Oxidation of sulfurous acid KW - Oxygen reduction reaction KW - Oxidative dehydrogenation of ethylbenzene Y1 - 2026 U6 - https://doi.org/10.1016/j.micromeso.2026.114129 SN - 1873-3093 VL - 407 SP - 1 EP - 11 PB - Elsevier BV CY - Amsterdam ER -