@misc{KlepelScholzScholzetal., author = {Klepel, Olaf and Scholz, Kerstin and Scholz, Jan and McQuillan, A. James and Wagner, Gerald}, title = {Partially embedded highly dispersed Pt nanoparticles in mesoporous carbon with enhanced leaching stability}, series = {Carbon}, volume = {48}, journal = {Carbon}, number = {6}, issn = {0008-6223}, pages = {1788 -- 1798}, language = {en} } @misc{GuentherKlepel, author = {G{\"u}nther, David and Klepel, Olaf}, title = {Synthese von por{\"o}sen Kohlenstoffmonolithen unter Verwendung von Porenbeton als Templat}, series = {Chemie Ingenieur Technik}, volume = {85}, journal = {Chemie Ingenieur Technik}, number = {6}, issn = {1522-2640}, pages = {955 -- 959}, language = {de} } @misc{WalterKlepelErleretal., author = {Walter, Reni and Klepel, Olaf and Erler, Thomas and Bron, Michael and Niebrzydowska, Paula and Wach, Anna and Kuśtrowski, Piotr}, title = {First steps on the way to a modular concept for the preparation of carbon based catalysts}, series = {Catalysis Letters}, volume = {143}, journal = {Catalysis Letters}, number = {7}, issn = {1572-879X}, pages = {642 -- 650}, language = {en} } @misc{TaubertBeckmannLangeetal., author = {Taubert, Michael and Beckmann, Jens and Lange, Andreas and Enke, Dirk and Klepel, Olaf}, title = {Attempts to design porous carbon monoliths using porous concrete as a template}, series = {Microporous and Mesoporous Materials}, volume = {Vol. 197}, journal = {Microporous and Mesoporous Materials}, issn = {1387-1811}, pages = {58 -- 62}, language = {en} } @misc{UtgenanntHansenKlepeletal., author = {Utgenannt, Stephan and Hansen, Felix and Klepel, Olaf and Jarczewski, Sebastian and Wach, Anna and Kuśtrowski, Piotr}, title = {Control of porosity and composition of carbon based catalysts prepared by template assisted routes}, series = {Catalysis Today}, volume = {Vol. 249}, journal = {Catalysis Today}, issn = {0920-5861}, doi = {10.1016/j.cattod.2014.10.036}, pages = {38 -- 44}, language = {en} } @misc{KlepelTaubertHeideretal., author = {Klepel, Olaf and Taubert, Michael and Heider, Robert and Erlitz, Marcel and Hille, Eva and Lange, Andreas and Enke, Dirk}, title = {Synthese von por{\"o}sen Kohlenstoffmonolithen unter Verwendung von Porenbeton als Templat. Teil II: Untersuchungen mechanischer Eigenschaften}, series = {Chemie Ingenieur Technik}, volume = {87}, journal = {Chemie Ingenieur Technik}, number = {7}, issn = {1522-2640}, doi = {10.1002/cite.201400089}, pages = {998 -- 1002}, language = {de} } @misc{KlepelErlitzScholzetal., author = {Klepel, Olaf and Erlitz, Marcel and Scholz, Kerstin and Suckow, Matthias and Taubert, Michael and Utgenannt, Stephan and Garsuch, Arnd}, title = {Template assisted synthesis of porous carbons revisited - where does the porosity come from?}, series = {Microporous and Mesoporous Materials}, journal = {Microporous and Mesoporous Materials}, number = {vol. 224}, issn = {1387-1811}, doi = {10.1016/j.micromeso.2015.11.047}, pages = {163 -- 167}, language = {en} } @misc{KlepelDannebergDraegeretal., author = {Klepel, Olaf and Danneberg, Nina and Dr{\"a}ger, Matti and Erlitz, Marcel and Taubert, Michael}, title = {Synthesis of Porous Carbon Monoliths Using Hard Templates}, series = {Materials}, volume = {9}, journal = {Materials}, number = {3}, issn = {1996-1944}, doi = {10.3390/ma9030214}, pages = {14}, language = {en} } @misc{GuentherBeckmannSchoeneichetal., author = {G{\"u}nther, David and Beckmann, Jens and Sch{\"o}neich, Michael and Schmidt, Peer and Klepel, Olaf}, title = {Porous concrete as a template for the synthesis of porous carbon materials}, series = {Carbon}, volume = {50}, journal = {Carbon}, number = {8}, issn = {0008-6223}, doi = {10.1016/j.carbon.2012.02.039}, pages = {3092 -- 3116}, abstract = {The potential of industrial porous concrete for using as a template for the synthesis of porous carbon materials has been investigated. Carbon replicas of porous concrete have been prepared by carbonization of sucrose. The pores of the resulting carbon materials range from the macropore to the micropore region, pointing to a hierarchy.}, language = {en} } @misc{KlepelDannebergSuckowetal., author = {Klepel, Olaf and Danneberg, Nina and Suckow, Matthias and Erlitz, Marcel}, title = {Carbon Replicas of Porous Concrete Obtained by Chemical Vapor Deposition - Some Aspects of the Synthesis Mechanism}, series = {Materials Sciences and Applications}, volume = {8}, journal = {Materials Sciences and Applications}, number = {8}, issn = {2153-117X}, doi = {10.4236/msa.2017.88043}, pages = {614 -- 627}, language = {en} } @misc{ReichardtUtgenanntStahmannetal., author = {Reichardt, Christina and Utgenannt, Stephan and Stahmann, Klaus-Peter and Klepel, Olaf and Barig, Susann}, title = {Highly stable adsorptive and covalent immobilization of Thermomyces lanuginosus lipase on tailor-made porous carbon material}, series = {Biochemical Engineering Journal}, journal = {Biochemical Engineering Journal}, number = {138}, issn = {1873-295X}, doi = {10.1016/j.bej.2018.07.003}, pages = {63 -- 73}, abstract = {Hierarchically structured, porous carbon materials (PCM) were synthesized by sucrose infiltration into template material and subsequent carbonization. Three porous carbon materials were prepared using porous concrete (PCM-01) or silica gel (PCM-02 and 03) as template. Carbon particles from 125 to 200 μm were generated. Surface carboxylic group density was determined with 1.1 mmol/g dry material for each variant. Firstly, tailor-made PCM was evaluated as suitable support for lipase immobilization. Recombinant produced lipase of Thermomyces lanuginosus (TLL) was used as model enzyme. Two independent crude immobilization strategies were applied. Residual activities of up to 8.6 U/g and 31 U/g dry material for adsorptive and covalent immobilization (linkage via EDC) were achieved, respectively. Additionally, TLL was immobilized on commercially available polymethacrylate support showing similar residual lipase activities. Secondly, covalent immobilization was optimized to generate reproducible, highly stable and active immobilizates. Optimized covalent immobilizates showed residual activities of up to 10 U∙g⁻¹ dry carbon material using p-nitrophenyl-palmitate assay and protein loads of up to 45 mg g⁻¹dry carbon material. Covalent bound TLL-PCM showed storage stability for 12 months, remaining 100\% of the initial activity. Operational stability resulted in stable and 100\% active immobilizates over five consecutive cycles of use. Experiments showed that tailor-made porous carbon material is a promising support for lipase immobilization, which is adaptable in shape and dimension.}, language = {en} } @misc{KlepelLangeUtgenannt, author = {Klepel, Olaf and Lange, Felix and Utgenannt, Stephan}, title = {Oxidation of sulfurous acid on carbon catalysts as a test reaction revisited: potential and limitations}, series = {Chemical engineering \& technology}, volume = {41}, journal = {Chemical engineering \& technology}, number = {10}, issn = {1521-4125}, doi = {10.1002/ceat.201800227}, pages = {2087 -- 2092}, language = {en} } @inproceedings{BarigUtgenanntHeineetal., author = {Barig, Susann and Utgenannt, Stephan and Heine, Alexander and Reichardt, Christina and Klepel, Olaf and Schnitzlein, Klaus and Stahmann, Klaus-Peter}, title = {Por{\"o}ses Kohlenstoffmaterial zur Immobilisierung von Lipase-Vergleichende Messungen mit Methacryl-Beads}, series = {Chemie Ingenieur Technik}, volume = {88}, booktitle = {Chemie Ingenieur Technik}, number = {9}, issn = {1522-2640}, doi = {10.1002/cite.201650097}, pages = {S. 1243}, abstract = {Zur Immobilisierung von Enzymen kann man Tr{\"a}ger kaufen oder diese selbst herstellen. In fr{\"u}heren Arbeiten wurde ein Verfahren entwickelt, um hochpor{\"o}se Kohlenstoffmaterialien in beliebigen Dimensionen herzustellen. Als Modell-Enzym zur Immobilisierung wurde die Thermomyces lanuginosus Lipase (TLL) gew{\"a}hlt, die adsorptiv und kovalent an das Material sowie an zwei k{\"a}ufliche Tr{\"a}germaterialien auf Polymethacryl-Basis (Funktionalit{\"a}ten: Ethylendiamin- bzw. Diolgruppen)gebunden werden sollten. Es wurden Kohlenstoffgranulat (d = 125 -200 mm) und zylindrische Monolithe (h = 4 cm; d = 1 cm) synthetisiert. Die adsorptive Immobilisierung ergab am Kohlenstoffgranulat Aktivit{\"a}ten von bis zu 2,5Ug⁻¹ gegen{\"u}ber p-Nitrophenyl Palmitat (pNPP). Bei den zwei k{\"a}uflichen Materialien wurden Aktivit{\"a}ten von bis zu 1,8Ug⁻¹ erreicht. Mit der kovalenten Immobilisierung konnten Aktivit{\"a}ten von bis zu 10Ug⁻¹ am Kohlenstoffmaterial sowie dem Polymethacryl-Material (-OH funktionalisiert) gegen{\"u}ber pNPP erreicht werden. Das Kohlenstoffmaterial ist ein geeigneter Tr{\"a}ger f{\"u}r die TLL, der im Vergleich mit g{\"a}ngigen Materialien Aktivit{\"a}ten in der gleichen Gr{\"o}ßenordnung zul{\"a}sst. Das Porenvolumen des Materials sowie die Makroporosit{\"a}t k{\"o}nnten erh{\"o}ht werden, um Diffusions- und Durchstr{\"o}mungsbarrieren im Monolithen abzubauen.}, language = {de} } @techreport{Klepel, author = {Klepel, Olaf}, title = {Entwicklung mikropor{\"o}ser Kohlenstoffmonolithe f{\"u}r Anwendungen in der Luft- und K{\"a}ltetechnik}, publisher = {Brandenburgische Technische Universit{\"a}t}, address = {Cottbus ; Senftenberg}, doi = {10.2314/GBV:870371126}, pages = {40}, language = {de} } @misc{KlepelTaubert, author = {Klepel, Olaf and Taubert, Michael}, title = {Attempts to design porous carbon monoliths using porous concrete as a template - Part II: Some aspects of the pore formation mechanism}, series = {Microporous Mesoporous Mater}, volume = {280}, journal = {Microporous Mesoporous Mater}, issn = {1387-1811}, doi = {10.1016/j.micromeso.2019.02.024}, pages = {243 -- 247}, language = {en} } @inproceedings{KlepelWalterGuentheretal., author = {Klepel, Olaf and Walter, Reni and G{\"u}nther, David and Niebrzydowska, Paula and Wach, Anna and Kuśtrowski, Piotr}, title = {Carbon materials prepared by template assisted routes as catalysts for oxidative dehydrogenation of ethylbenzene}, series = {5th International Sypmosium on "Carbon on Catalysis", Books of abstracts, Bressanone/Brixen, 2012}, booktitle = {5th International Sypmosium on "Carbon on Catalysis", Books of abstracts, Bressanone/Brixen, 2012}, pages = {S. 92}, language = {en} } @inproceedings{WalterGuentherKlepeletal., author = {Walter, Reni and G{\"u}nther, David and Klepel, Olaf and Schilling, Thorsten and Erler, Thomas and Bron, Michael}, title = {Carbon materials prepared by template assisted routes as catalysts for electrochemical oxygen reduction}, series = {5th International Sypmosium on "Carbon on Catalysis", Books of abstracts, Bressanone/Brixen, 2012}, booktitle = {5th International Sypmosium on "Carbon on Catalysis", Books of abstracts, Bressanone/Brixen, 2012}, pages = {S. 93}, language = {en} } @inproceedings{TaubertBeckmannZimmermannetal., author = {Taubert, Michael and Beckmann, Jens and Zimmermann, J{\"o}rg and Lange, Andreas and Enke, Dirk and Klepel, Olaf}, title = {Template synthesis of carbon monoliths based on porous concrete}, series = {Carbon materials for ubiquitous and sustainable life : Annual World Conference on Carbon (Carbon 2014) ; Jeju, Korea, 27 June - 4 July 2014 ; [abstracts]}, booktitle = {Carbon materials for ubiquitous and sustainable life : Annual World Conference on Carbon (Carbon 2014) ; Jeju, Korea, 27 June - 4 July 2014 ; [abstracts]}, publisher = {Curran}, address = {Red Hook, NY}, isbn = {9781634399050}, pages = {S. 511}, language = {en} } @inproceedings{ErlitzDannebergKlepel, author = {Erlitz, Marcel and Danneberg, Nina and Klepel, Olaf}, title = {Template assisted synthesis of porous carbon: insight in the process of the carbon deposition in the template}, series = {Carbon 2015 : innovation with carbon materials; the Annual World Conference on Carbon, Dresden, Germany, July 12 - 17, 2015}, booktitle = {Carbon 2015 : innovation with carbon materials; the Annual World Conference on Carbon, Dresden, Germany, July 12 - 17, 2015}, publisher = {Deutsche Keramische Gesellschaft e.V.}, address = {K{\"o}ln}, pages = {S. 21}, language = {en} } @inproceedings{TaubertDraegerEnkeetal., author = {Taubert, Michael and Dr{\"a}ger, Matti and Enke, Dirk and Klepel, Olaf}, title = {Carbon monoliths with hierarchical pore system obtained by template assisted synthesis}, series = {Carbon 2015 : innovation with carbon materials; the Annual World Conference on Carbon, Dresden, Germany, July 12 - 17, 2015}, booktitle = {Carbon 2015 : innovation with carbon materials; the Annual World Conference on Carbon, Dresden, Germany, July 12 - 17, 2015}, publisher = {Deutsche Keramische Gesellschaft e.V.}, address = {K{\"o}ln}, pages = {S. 41}, language = {en} } @inproceedings{UtgenanntHansenKlepeletal., author = {Utgenannt, Stephan and Hansen, Felix and Klepel, Olaf and Jarczewski, Sebastian and Wach, Anna and Kustrowski, Piotr and Erler, Thomas and Bron, Michael}, title = {A modular concept for the preparation of carbon based catalysts}, series = {Carbon 2015 : innovation with carbon materials; the Annual World Conference on Carbon, Dresden, Germany, July 12 - 17, 2015}, booktitle = {Carbon 2015 : innovation with carbon materials; the Annual World Conference on Carbon, Dresden, Germany, July 12 - 17, 2015}, publisher = {Deutsche Keramische Gesellschaft e.V.}, address = {K{\"o}ln}, pages = {S. 294}, language = {en} } @inproceedings{BeckmannGuentherSchmidtetal., author = {Beckmann, Jens and G{\"u}nther, David and Schmidt, Peer and Sch{\"o}neich, Michael and Klepel, Olaf}, title = {Template assisted synthesis of porous carbon materials using porous concrete as a template}, series = {5th International Sypmosium on "Carbon on Catalysis", Books of abstracts, Bressanone/Brixen, 2012}, booktitle = {5th International Sypmosium on "Carbon on Catalysis", Books of abstracts, Bressanone/Brixen, 2012}, pages = {S. 94}, language = {en} } @inproceedings{WalterGuentherKlepeletal., author = {Walter, Reni and G{\"u}nther, David and Klepel, Olaf and Niebrzydowska, Paula and Wach, Anna and Kuśtrowski, Piotr}, title = {Carbon catalysts obtained by template assisted routes for oxidative dehydrogenation of ethylbenzene}, series = {Annual World Conference on Carbon : (Carbon 2012) Krakow, Poland 17-22 June 2012}, volume = {1}, booktitle = {Annual World Conference on Carbon : (Carbon 2012) Krakow, Poland 17-22 June 2012}, publisher = {Curran}, address = {Red Hook, NY}, isbn = {978-1-62993-436-5}, pages = {848}, language = {en} } @inproceedings{WalterGuentherKlepeletal., author = {Walter, Reni and G{\"u}nther, David and Klepel, Olaf and Schilling, Thorsten and Erler, Thomas and Bron, Michael}, title = {Carbon catalysts prepared by template assisted routes for electrochemical oxygen reduction}, series = {Annual World Conference on Carbon : (Carbon 2012) Krakow, Poland 17-22 June 2012}, volume = {1}, booktitle = {Annual World Conference on Carbon : (Carbon 2012) Krakow, Poland 17-22 June 2012}, publisher = {Curran}, address = {Red Hook, NY}, isbn = {978-1-62993-436-5}, pages = {853}, language = {en} } @inproceedings{BeckmannGuentherKlepeletal., author = {Beckmann, Jens and G{\"u}nther, David and Klepel, Olaf and Schmidt, Peer}, title = {Porous concrete as a template for the synthesis of porous carbon materials}, series = {Annual World Conference on Carbon : (Carbon 2012) Krakow, Poland 17-22 June 2012}, booktitle = {Annual World Conference on Carbon : (Carbon 2012) Krakow, Poland 17-22 June 2012}, publisher = {Curran}, address = {Red Hook, NY}, isbn = {978-1-62993-436-5}, pages = {854}, language = {en} } @inproceedings{TaubertBeckmannZimmermannetal., author = {Taubert, Michael and Beckmann, Jens and Zimmermann, J{\"o}rg and Lange, Andreas and Enke, Dirk and Klepel, Olaf}, title = {Carbon monoliths obtained from porous concrete as a template}, series = {Porous systems: from novel materials to sustainable solutions : 6th FEZA conference : 8 - 11 September 2014, Universit{\"a}t Leipzig, Germany ; book of abstracts}, booktitle = {Porous systems: from novel materials to sustainable solutions : 6th FEZA conference : 8 - 11 September 2014, Universit{\"a}t Leipzig, Germany ; book of abstracts}, publisher = {DECHEMA}, address = {Frankfurt am Main}, pages = {S. 269}, language = {en} } @inproceedings{UtgenanntVormelchertKlepeletal., author = {Utgenannt, Stephan and Vormelchert, Carolin and Klepel, Olaf and Jarczewski, Sebastian and Drozdek, Michal and Kustrowski, Piotr and Erler, Thomas and R{\"u}mmler, Stephan and Bron, Michael}, title = {Template assisted synthesis of porous carbon catalysts with systematically varied properties}, series = {The zeolites : materials with engineered properties : book of abstracts / 7th FEZA Conference, July 3-7, 2017, Sofia, Bulgaria}, booktitle = {The zeolites : materials with engineered properties : book of abstracts / 7th FEZA Conference, July 3-7, 2017, Sofia, Bulgaria}, address = {Sofia}, pages = {S. 199}, language = {en} } @inproceedings{BoelteUtgenanntKlepeletal., author = {B{\"o}lte, Jens-Henning Ingo Holger and Utgenannt, Stephan and Klepel, Olaf and Erler, Thomas and R{\"u}mmler, Stephan and Bron, Michael}, title = {Heteroatom doped porous carbon catalysts with systematically varied properties obtained by template assisted synthesis}, series = {Book of abstracts, 8th International Symposium on Carbon for Catalysis, CarboCat-VIII, 26. - 29.06. 2018, Porto}, booktitle = {Book of abstracts, 8th International Symposium on Carbon for Catalysis, CarboCat-VIII, 26. - 29.06. 2018, Porto}, publisher = {Sociedade Portuguesa de Qu{\´i}mica}, address = {Porto}, isbn = {978-989-8124-22-7}, pages = {S. 69}, language = {en} } @misc{KlepelDanneberg, author = {Klepel, Olaf and Danneberg, Nina}, title = {Porous Carbon Monoliths Made from Cellulose and Starch}, series = {C - Journal of Carbon Research}, volume = {6}, journal = {C - Journal of Carbon Research}, number = {2}, issn = {2311-5629}, doi = {10.3390/c6020032}, pages = {11}, language = {en} } @incollection{Klepel, author = {Klepel, Olaf}, title = {Ha ho he wir hassen den BFC! oder die Mauer muss weg!}, series = {Sushi, Sandmann, Sozialismus: Kultur- und Landeskunde der DDR : Ein Text- und {\"U}bungsbuch f{\"u}r den DaF-Unterricht}, booktitle = {Sushi, Sandmann, Sozialismus: Kultur- und Landeskunde der DDR : Ein Text- und {\"U}bungsbuch f{\"u}r den DaF-Unterricht}, editor = {Witzlack-Makarevich, Kai and Wulff, Nadja and Storz, Coretta}, edition = {1. Auflage}, publisher = {Frank \& Timme Verlag f{\"u}r wissenschaftliche Literatur}, address = {Berlin}, isbn = {978-3-7329-0686-4}, pages = {212 -- 214}, language = {de} } @misc{GonzalezCastanoNavarrodeMiguelSinhaetal., author = {Gonz{\´a}lez-Casta{\~n}o, Miriam and Navarro de Miguel, Juan Carlos and Sinha, F. and Ghomsi Wabo, Samuel and Klepel, Olaf and Arellano-Garc{\´i}a, Harvey}, title = {Cu supported Fe-SiO2 nanocomposites for reverse water gas shift reaction}, series = {Journal of CO2 Utilization}, volume = {46}, journal = {Journal of CO2 Utilization}, issn = {2212-9820}, doi = {10.1016/j.jcou.2021.101493}, pages = {8}, abstract = {This work analyses the catalytic activity displayed by Cu/SiO2, Cu-Fe/SiO2 and Cu/FSN (Fe-SiO2 nanocomposite) catalysts for the Reverse Water Gas Shift reaction. Compared to Cu/SiO2 catalyst, the presence of Fe resulted on higher CO's selectivity and boosted resistances against the constitution of the deactivation carbonaceous species. Regarding the catalytic performance however, the extent of improvement attained through incorporation Fe species strongly relied on the catalysts' configuration. At 30 L/gh and H2:CO2 ratios = 3, the performance of the catalysts' series increased according to the sequence: Cu/SiO2 < Cu-Fe/SiO2 << Cu/FSN. The remarkable catalytic enhancements provided by Fe-SiO2 nanocomposites under different RWGS reaction atmospheres were associated to enhanced catalyst surface basicity's and stronger Cu-support interactions. The catalytic promotion achieved by Fe-SiO2 nanocomposites argue an optimistic prospective for nanocomposite catalysts within future CO2-valorising technologies.}, language = {en} } @misc{GhomsiWaboKlepel, author = {Ghomsi Wabo, Samuel and Klepel, Olaf}, title = {Nitrogen release and pore formation through KOH activation of nitrogen‑doped carbon materials: an evaluation of the literature}, series = {Carbon Letters}, journal = {Carbon Letters}, issn = {2233-4998}, doi = {10.1007/s42823-021-00252-3}, pages = {12}, language = {en} } @misc{KlepelUtgenanntVormelchertetal., author = {Klepel, Olaf and Utgenannt, Stephan and Vormelchert, Carolin and K{\"o}nig, Mark and Meißner, Andr{\´e} and Hansen, Felix and B{\"o}lte, Jens-Henning Ingo Holger and Sieber, Tim and Heinemann, Robert and Bron, Michael and Rokicinska, Anna and Jarczewski, Sebastian and Kustrowski, Piotr}, title = {Redox catalysts based on amorphous porous carbons}, series = {Microporous Mesoporous Materials}, volume = {323}, journal = {Microporous Mesoporous Materials}, issn = {1387-1811}, doi = {10.1016/j.micromeso.2021.111257}, pages = {12}, language = {en} } @misc{GonzalezCastanoNavarrodeMiguelBoelteetal., author = {Gonzalez-Castano, Miriam and Navarro de Miguel, Juan Carlos and Boelte, Jens-H. and Centeno, Miguel Angel and Klepel, Olaf and Arellano-Garc{\´i}a, Harvey}, title = {Assessing the impact of textural properties in Ni-Fe catalysts for CO2 methanation performance}, series = {Microporous and Mesoporous Materials}, volume = {327}, journal = {Microporous and Mesoporous Materials}, issn = {1387-1811}, doi = {10.1016/j.micromeso.2021.111405}, pages = {7}, abstract = {In heterogeneous catalysis, the benefits of employing adequate textural properties on the catalytic performances are usually stated. Nevertheless, the quantification of the extent of improvement is not an easy task since variations on the catalysts' specific areas and pore structures might involve modifications on a number of other surface catalytic features. This study establishes the impact of the catalyst textural properties on the CO2 methanation performance by investigating bimetallic Ni-Fe catalysts supported over carbon supports with different textural properties regarding surface area and pore structure. The comparable metal loading and dispersions attained for all systems enabled establishing forthright relationships between the catalyst textural properties and CO2 methanation rate. Once the influence of the external mass diffusions on the catalysts' performance was experimentally discarded, the estimated Thiele modulus and internal effectiveness (φ and ηEff) values showed that the catalyst performance was majorly governed by the surface reaction rate whilst the pore size affected in no significant manner within the examined range (Dpore = 10.2 to 5.8 nm). Therefore, the rapport between the catalyst performance and surface area was quantified for the CO2 methanation reaction over Ni-Fe catalysts: increasing the surface area from 572 to 802 m2/g permit obtaining ca. 10\% higher CO2 conversions.}, language = {en} } @misc{PlattfautSuckowKlepeletal., author = {Plattfaut, Julia and Suckow, Matthias and Klepel, Olaf and Erlitz, Marcel and Arellano-Garc{\´i}a, Harvey}, title = {Modellierung und Simulation der templatgest{\"u}tzten Synthese von por{\"o}sen Kohlenstoffger{\"u}sten mittels COMSOL Multiphysics}, series = {Chemie Ingenieur Technik}, volume = {96(2024)}, journal = {Chemie Ingenieur Technik}, number = {3}, issn = {1522-2640}, doi = {10.1002/cite.202300014}, pages = {318 -- 328}, abstract = {Mithilfe einer templatgest{\"u}tzten Synthese wurden por{\"o}se Kohlenstoffger{\"u}ste unter Verwendung von Silicagel als Templat hergestellt. Die chemische Gasphaseninfiltration (CVI) wurde hierbei als Synthese verwendet. Unter Variation verschiedener Reaktionsparameter zur Optimierung der Kohlenstoffabscheidung wurde dieser Prozess mathematisch modelliert and simuliert. Dabei konnten die experimentellen Ergebnisse gut mit den Modellen nachgebildet werden. Die zus{\"a}tzliche Beschreibung der laminaren Str{\"o}mung verbessert die {\"U}bereinstimmung deutlich.}, language = {de} } @misc{GonzalezCastanoMoralesNavarrodeMigueletal., author = {Gonzalez-Cast{\~a}no, Miriam and Morales, Carlos and Navarro de Miguel, Juan Carlos and Boelte, Jens-H. and Klepel, Olaf and Flege, Jan Ingo and Arellano-Garc{\´i}a, Harvey}, title = {Are Ni/ and Ni5Fe1/biochar catalysts suitable for synthetic natural gas production? A comparison with γ-Al2O3 supported catalysts}, series = {Green Energy \& Environment}, volume = {8}, journal = {Green Energy \& Environment}, number = {3}, issn = {2468-0257}, doi = {10.1016/j.gee.2021.05.007}, pages = {744 -- 756}, abstract = {Among challenges implicit in the transition to the post-fossil fuel energetic model, the finite amount of resources available for the technological implementation of CO2 revalorizing processes arises as a central issue. The development of fully renewable catalytic systems with easier metal recovery strategies would promote the viability and sustainability of synthetic natural gas production circular routes. Taking Ni and NiFe catalysts supported over γ-Al2O3 oxide as reference materials, this work evaluates the potentiality of Ni and NiFe supported biochar catalysts for CO2 methanation. The development of competitive biochar catalysts was found dependent on the creation of basic sites on the catalyst surface. Displaying lower Turn Over Frequencies than Ni/Al catalyst, the absence of basic sites achieved over Ni/C catalyst was related to the depleted catalyst performances. For NiFe catalysts, analogous Ni5Fe1 alloys were constituted over both alumina and biochar supports. The highest specific activity of the catalyst series, exhibited by the NiFe/C catalyst, was related to the development of surface basic sites along with weaker NiFe-C interactions, which resulted in increased Ni0:NiO surface populations under reaction conditions. In summary, the present work establishes biochar supports as a competitive material to consider within the future low-carbon energetic panorama.}, language = {en} } @misc{BoelteUtgenanntSchmidtetal., author = {B{\"o}lte, Jens-Henning and Utgenannt, Stephan and Schmidt, Max and Klepel, Olaf and Bron, Michael and Rokicińska, Anna and Jarczewski, Sebastian and Kuśtrowski, Piotr}, title = {S-doped and N+S-co-doped carbon catalysts in redox reactions}, series = {Microporous and mesoporous materials}, volume = {407}, journal = {Microporous and mesoporous materials}, publisher = {Elsevier BV}, address = {Amsterdam}, issn = {1873-3093}, doi = {10.1016/j.micromeso.2026.114129}, pages = {1 -- 11}, abstract = {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.}, language = {en} }