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van Koppen, L.M. (author), Dugulan, A.I. (author), Hensen, Emiel J.M. (author), Bezemer, G. Leendert (author)Cobalt oxidation is a relevant deactivation pathway of titania-supported cobalt catalysts used in Fischer-Tropsch synthesis (FTS). To work towards more stable catalysts, we studied the effect of the surface area of the titania support and noble metal promotion on cobalt oxidation under simulated high conversion conditions. Mössbauer...journal article 2024
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Zhang, Hao (author), Bolshakov, Aleksei (author), Meena, Raghavendra (author), Garcia, Gustavo A. (author), Dugulan, A.I. (author), Parastaev, Alexander (author), Li, Guanna (author), Hensen, Emiel J.M. (author), Kosinov, Nikolay (author)Non-oxidative coupling of methane is a promising route to obtain ethylene directly from natural gas. We synthesized siliceous [Fe]zeolites with MFI and CHA topologies and found that they display high selectivity (>90 % for MFI and >99 % for CHA) to ethylene and ethane among gas-phase products. Deactivated [Fe]zeolites can be regenerated...journal article 2023
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van Koppen, L.M. (author), Dugulan, A.I. (author), Leendert Bezemer, G. (author), Hensen, Emiel J.M. (author)The study of titania-supported cobalt nanoparticles is relevant for industrial Fischer-Tropsch synthesis (FTS). Herein, we report about various deactivation pathways of cobalt supported on P25 titania (cobalt loading 2–8 wt%) under simulated high conversion conditions using in situ Mössbauer spectroscopy. A fraction of metallic cobalt was...journal article 2023
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van Koppen, L.M. (author), Dugulan, A.I. (author), Leendert Bezemer, G. (author), Hensen, Emiel J.M. (author)Understanding the deactivation mechanism of cobalt-based Fischer-Tropsch catalysts is of significant practical importance. Herein, we explored the role of manganese as a structural promoter on silica-supported cobalt nanoparticles under simulated high CO conversion conditions, i.e., high relative humidity. The structural changes in cobalt...journal article 2023
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Ariëns, M.I. (author), van de Water, L. G.A. (author), Dugulan, A.I. (author), Brück, E.H. (author), Hensen, E. J.M. (author)Copper promotion of chromium-doped iron oxide prepared via co-precipitation for high-temperature water–gas shift (WGS) catalysis is investigated. Low-temperature Mössbauer spectra demonstrate that copper doping delays hematite (α-Fe<sub>2</sub>O<sub>3</sub>) formation in the fresh catalyst, favoring the formation of small crystallites of...journal article 2022
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Chai, Jiachun (author), Pestman, Robert (author), Chen, Wei (author), Donkervoet, Noortje (author), Dugulan, A.I. (author), Men, Zhuowu (author), Wang, Peng (author), Hensen, Emiel J.M. (author)The kinetics of the transformation of metallic Fe to the active Fe carbide phase at the start of the Fischer-Tropsch (FT) reaction were studied. The diffusion rates of C atoms going in or out of the lattice were determined using 13C-labeled synthesis gas in combination with measurements of the transient 12C and 13C contents in the carbide by...journal article 2022
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Ariëns, M.I. (author), Van De Water, L. G.A. (author), Dugulan, A.I. (author), Brück, E.H. (author), Hensen, E. J.M. (author)A set of doped iron oxides (chromium, aluminum, gallium, indium, manganese, zinc, niobium) were prepared by a one-step coprecipitation/calcination approach evaluated for their WGS activity under industrially relevant conditions and characterized in detail. The WGS activity after ageing the doped catalyst for 4 days at 25 bar follows the order...journal article 2022
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van Koppen, L.M. (author), Dugulan, A.I. (author), Hensen, Emiel J.M. (author), Bezemer, G. Leendert (author)The commercial application of cobalt-based Fischer-Tropsch synthesis (FTS) suffers from catalyst deactivation. One of the main deactivation mechanisms under industrial conditions is sintering. In this work, we explored the role of manganese oxide as a structural promoter against sintering in a carbon nanofiber supported cobalt model catalyst....journal article 2022
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Xu, L. (author), Guo, Fang (author), Hoes, Pieter-Jan (author), Yang, Xudong (author), Hensen, Jan (author)This paper presents a modeling and simulation method that supports energy performance assessment and operation strategy investigation of borehole thermal energy storage in the Chifeng district heating (DH) system. A living laboratory in Chifeng, China that integrates a 0.5 million m3 borehole thermal energy storage system, an on-site solar...journal article 2021
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Chai, Jiachun (author), Pestman, Robert (author), Chen, Wei (author), Dugulan, A.I. (author), Feng, Bo (author), Men, Zhuowu (author), Wang, Peng (author), Hensen, Emiel J.M. (author)The formation of Fe-carbide phases is relevant to the synthesis of Fischer-Tropsch synthesis catalysts. We investigated the carburization of Raney Fe as a model catalyst using spectroscopic and temperature-programmed techniques. IR spectroscopy shows that CO dissociation already occurs at −150 °C, while C diffusion into metallic Fe requires...journal article 2021
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Ariëns, M.I. (author), Chlan, V. (author), Novák, P. (author), van de Water, L. G.A. (author), Dugulan, A.I. (author), Brück, E.H. (author), Hensen, E. J.M. (author)Chromium promotion of iron oxide based water-gas shift (WGS) catalysts prepared via co-precipitation/calcination was investigated. Mössbauer spectroscopy and XRD evidence that chromium is incorporated in the calcined hematite (α-Fe<sub>2</sub>O<sub>3</sub>) precursor irrespective of the doping level (0−12 wt.%). CO-TPR shows chromium delays...journal article 2021
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Marinković, Igor (author), Drimmer, Maxwell (author), Hensen, B.J. (author), Groeblacher, S. (author)The rapid development of quantum information processors has accelerated the demand for technologies that enable quantum networking. One promising approach uses mechanical resonators as an intermediary between microwave and optical fields. Signals from a superconducting, topological, or spin qubit processor can then be converted coherently to...journal article 2021
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Krans, Nynke A. (author), Van Uunen, Dónal L. (author), Versluis, Caroline (author), Dugulan, A.I. (author), Chai, Jiachun (author), Hofmann, Jan P. (author), Hensen, Emiel J.M. (author), Zečević, Jovana (author), De Jong, Krijn P. (author)Using model catalysts with well-defined particle sizes and morphologies to elucidate questions regarding catalytic activity and stability has gained more interest, particularly utilizing colloidally prepared metal(oxide) particles. Here, colloidally synthesized iron oxide nanoparticles (FexOy-NPs, size ∼7 nm) on either a titania (FexOy/TiO2)...journal article 2020
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Franz, R.P.M. (author), Kühlewind, T.S. (author), Shterk, Genrikh (author), Abou-Hamad, Edy (author), Parastaev, Alexander (author), Uslamin, E. (author), Hensen, Emiel J M (author), Kapteijn, F. (author), Gascon, Jorge (author), Pidko, E.A. (author)Coke deposition is one of the main challenges in the commercialisation of dry reforming of methane oversupported Ni catalysts. Besides the coke quantity, the structure of the deposits is also essential for thecatalyst lifetime. Accordingly, in this study, we analysed the effect of Na, K, and Cs promoters on boththese variables over Ni...journal article 2020
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Eisma, Y.B. (author), van Bergen, Steven (author), ter Brake, Sjoerd (author), Hensen, Matthijs (author), Tempelaar, Willem Jan (author), de Winter, J.C.F. (author)In the future, automated cars may feature external human–machine interfaces (eHMIs) to communicate relevant information to other road users. However, it is currently unknown where on the car the eHMI should be placed. In this study, 61 participants each viewed 36 animations of cars with eHMIs on either the roof, windscreen, grill, above the...journal article 2020
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Li, J. (author), Wallucks, A. (author), da Silva Benevides, R. (author), Fiaschi, N. (author), Hensen, B.J. (author), Mayer Alegre, Thiago P. (author), Groeblacher, S. (author)We present a discrete-variable quantum teleportation scheme using pulsed optomechanics. In our proposal, we demonstrate how an unknown optical input state can be transferred onto the joint state of a pair of mechanical oscillators, without physically interacting with one another. We further analyze how experimental imperfections will affect...journal article 2020
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- Galliker, Manuel (author), Schläfli, Florian (author), Bättig, Rik (author), Hensen, Micha (author), Kader, Barzy (author), Macuglia, Mael (author), Mark, Jonas (author), Pagani, Michelle (author), Sigron, Pirmin (author), Zemp, Cédric (author), Fasel, Urban (author), Keidel, Dominic (author), Schlothauer, Arthur (author), Ermanni, Paolo (author) conference paper 2019
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Uslamin, E. (author), Kosinov, N. (author), Filonenko, G.A. (author), Mezari, Brahim (author), Pidko, E.A. (author), Hensen, Emiel J.M. (author)Aromatization of furan and substituted furans over zeolite catalysts is a promising reaction to convert cellulose-derived compounds into valuable aromatic hydrocarbons and light olefins. A lack of understanding of the reaction mechanism however hinders further development of this process. Here, we propose the reaction mechanism, underlying...journal article 2019
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Vollmer, I. (author), Kosinov, N. (author), Szécsényi, Ágnes (author), Li, G. (author), Yarulina, I. (author), Abou-Hamad, Edy (author), Gurinov, Andrei (author), Ould-Chikh, Samy (author), Aguilar-Tapia, Antonio (author), Hazemann, Jean Louis (author), Pidko, E.A. (author), Hensen, Emiel (author), Kapteijn, F. (author), Gascon, Jorge (author)The active sites on the methane dehydroaromatization (MDA) catalyst Mo/HZSM-5 are very hard to characterize, because they are present in various geometries and sizes and only form under reaction conditions with methane at 700 °C. To address these issues an experimental strategy is presented that enables distinguishing different active sites...journal article 2019
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Rohling, Roderigh Y. (author), Tranca, Ionut C. (author), Hensen, Emiel J.M. (author), Pidko, E.A. (author)The Diels-Alder cycloaddition (DAC) reaction is a commonly employed reaction for the formation of C-C bonds. DAC catalysis can be achieved by using Lewis acids and via reactant confinement in aqueous nanocages. Low-silica alkali-exchanged faujasite catalysts combine these two factors in one material. They can be used in the tandem DAC...journal article 2018