Article
Chemistry, Physical
Katharina M. Golder, Joost Wintterlin
Summary: The Co(10(1) over bar 15) surface, a vicinal surface of Co(0001), exhibits higher activity compared to the Co(0001) surface, showing that atomic steps are the active sites. This suggests that the Co(10(1) over bar 15) surface can serve as a model system bridging the materials gap between single crystals and supported catalysts, with activities comparable to supported Co catalysts reported in literature data.
Article
Chemistry, Applied
Prasad Gonugunta, A. Iulian Dugulan, G. Leendert Bezemer, Ekkes Bruck
Summary: Operando spectroscopic techniques were used to investigate the impact of oxygenates deposition on the deactivation of cobalt on titania Fischer-Tropsch catalysts under high pressure. It was found that catalysts prepared via impregnation had more and heavier carboxylates, likely due to higher olefin content in the products, leading to increased formation of oxygenates. Gas chromatography/infrared spectroscopy data indicated that the surface carboxylate species were not involved in catalyst deactivation, serving as spectator species on the titania support.
Article
Chemistry, Physical
Chuan Qin, Bo Hou, Jungang Wang, Zhongyi Ma, Congbiao Chen, Litao Jia, Debao Li, Mingyue Ding
Summary: The preparation of cobalt-based Fischer-Tropsch synthesis (FTS) catalysts that can be used directly in a fixed-bed reactor without the need for further reduction is crucial but challenging. This study addresses the problem by tuning the carbon deposits on the cobalt catalyst surface. A screen-like surface carbon can prevent the oxidation of metallic cobalt, resulting in high activity and low CH4 selectivity without further reduction. The role of surface carbon and penetrating carbon in FTS performance is explored, with surface carbon improving adsorption ability and long-chain hydrocarbon formation, while penetrating carbon increases undesired CH4 selectivity.
Article
Chemistry, Physical
Tobias F. Kimpel, Jin-Xun Liu, Wei Chen, Robert Pestman, Emiel J. M. Hensen
Summary: Through IR spectroscopy and DFT calculations, it has been discovered that in the Fischer-Tropsch reaction, Mn promotes a silica-supported Co catalyst with a MnO layer covering the Co surface, activating adsorbed CO through reaction with an oxygen vacancy. This results in higher activity, higher CHx coverage, increased C5+ selectivity, and decreased CH4 selectivity. Increasing pressure amplifies the selectivity differences. However, above around 4 bar, the addition of Mn decreases C5+ selectivity, possibly due to its promotion of C-O bond dissociation but not chain growth. Migration of formed monomers for chain growth on the Co surface may be hindered by high CO coverage, especially at high pressure.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Physical
C. J. (Kees-Jan) Weststrate, Daniel Garcia Rodriguez, Devyani Sharma, J. W. (Hans) Niemantsverdriet
Summary: This study investigates the interaction between hydrogen and cobalt surfaces, revealing the adsorption and desorption behavior of hydrogen on different surface structures. It also discovers the variation of hydrogen adsorption strength and equilibrium constant under different conditions.
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Physical
F. Platero, S. Todorova, L. Aoudjera, L. Michelin, B. Lebeau, J. L. Blin, J. P. Holgado, A. Caballero, G. Colon
Summary: In this study, cobalt catalyst supported on mesostructured TiO2 was prepared and subjected to calcination and reduction. The results showed that cobalt nanoparticles were uniformly distributed along the mesopore channels of TiO2, and the highly stable metal active sites contributed to the generation of C5+ products in Fischer-Tropsch synthesis reaction.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Materials Science, Ceramics
Ming Hao, Peizhang Gao, Wei Liu, Baizeng Fang, Jinsheng Liang, Tingting Zhang, Youpeng Ding, Hui Zhang, Fei Wang
Summary: A novel Co/CoAl2O4/sepiolite nanocomposite was synthesized in this study, with optimal conditions identified for fabrication. The nanocomposite showed fine cobalt nanoparticles anchored on the surface of CoAl2O4, leading to higher selectivity for high-carbon hydrocarbons in Fischer-Tropsch synthesis. This work provides an effective strategy for low-cost batch fabrication of efficient cobalt-based catalysts.
CERAMICS INTERNATIONAL
(2021)
Article
Energy & Fuels
Francisco Platero, Alfonso Caballero, Gerardo Colon
Summary: Cobalt supported TiO2 catalysts were prepared by wet-impregnation and by immobilization over APTES grafted TiO2. The impregnated system showed better catalytic performance after reduction at 260 degrees C, but significant deactivation was observed. In contrast, the functionalized catalyst showed better catalytic performance after reduction at 400 degrees C with notable stability. CO-DRIFT operando analysis revealed that the impregnated system was strongly affected by negative SMSI upon reduction at higher temperature, while immobilization on APTES hindered the loss of metal active sites. The study of spent catalysts indicated that Co was redispersed in the impregnated catalyst while functionalized catalyst tended to form agglomerates.
Article
Energy & Fuels
Dalia Liuzzi, Francisco J. Perez-Alonso, Sergio Rojas
Summary: Ru-Co/Al2O3 and Ru-Fe/Al2O3 catalysts prepared by reduction-deposition method exhibit high activity in Fischer-Tropsch Synthesis, showing different conversion rates and product selectivity. The interaction between Ru and Co in Ru-Co/Al2O3 enhances the activity, while Ru-Fe/Al2O3 displays superior initial performance but declines over time, with less enriched products compared to Ru/Al2O3.
Article
Materials Science, Multidisciplinary
Abdallah I. M. Rabee, Christin B. A. Gaid, Gamal A. H. Mekhemer, Mohamed I. Zaki
Summary: This study investigated the chemical composition, structure, thermal stability, topo-chemical interactivity, and reduction behavior of cobalt oxides (Co3O4, CoO, and Co2O3). The results showed that Co3O4 had a stable crystalline structure and underwent deoxygenation and oxygenation processes in different atmospheres. The reduction of Co3O4 involved five events, including the removal of surface oxygen species and the formation of CoO. The study also found that reduction variables had a significant impact on the temperature range and rate of reduction events.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Chemistry, Physical
Lebohang Macheli, Emanuela Carleschi, Bryan P. Doyle, Gerard Leteba, Eric van Steen
Summary: Metal-support interactions in inverse catalysts prepared by adsorbing TEOS on Co3O4 can be manipulated by varying the solvent mixture. Deposition of TEOS on Co3O4 nanoparticles in n-hexane results in the formation of silica oligomers interacting strongly with cobalt(II,III)oxide after calcination at 573 K. Modification of Co3O4 nanoparticles with TEOS in a hydrolysing environment results in a stronger interaction due to the formation of surface cobalt silicate through hydrolysis.
JOURNAL OF CATALYSIS
(2021)
Article
Chemistry, Physical
Ning Zhao, Yao Chen, Xin Li, Tao Chen, Mehar U. Nisa, Zhenhua Li
Summary: This study prepared amorphous Co2SiO4 material by in-situ doping TMOS during the synthesis of ZIF-67, which was then reduced at different temperature and time to obtain ReX-2h and Re500-Yh catalysts. The effects of reduction temperature and time on Co reduction degree and FTS performance were investigated. The results showed that increasing reduction temperature led to higher reduction degree and enhanced FTS activity, but the stability of the catalysts decreased for certain temperatures.
MOLECULAR CATALYSIS
(2023)
Article
Chemistry, Physical
Madita Einemann, Simon Haida, Nico Fischer, Nattawut Osakoo, Jatuporn Wittayakun, Frank Roessner
Summary: The role of cobalt chloride hexahydrate as a precursor of cobalt bulk catalysts was investigated for the Fischer-Tropsch reaction. Different oxygen-containing cobalt compounds were detected through in situ DRIFTS, in situ XANES, in situ XRD, and inverse TPR techniques. The reaction network of cobalt chloride transformation was discussed, taking into account the back mixing in different geometries of measuring cells. The choice of catalyst activation procedure is important for the formation of cobalt oxide and subsequent activity in the Fischer-Tropsch reaction.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Applied
Ljubisa Gavrilovic, Erik A. Jorgensen, Umesh Pandey, Koteswara R. Putta, Kumar R. Rout, Erling Rytter, Magne Hillestad, Edd A. Blekkan
Summary: Fischer-Tropsch synthesis has been investigated over a commercial cobalt-based catalyst, showing a positive effect of water on catalyst activity and increased C(5+) selectivity regardless of the H2/CO ratio. Increasing conversion led to increased C(5+) selectivity, while higher conversions resulted in significantly enhanced selectivity to CO2.
Article
Chemistry, Physical
Alexander Bagger, Oliver Christensen, Vladislav Ivanistsev, Jan Rossmeisl
Summary: This work investigates the theoretical differences and similarities of CO2/CO catalytic reduction reactions in gas, aqueous solution, and aprotic solution. The binding energy serves as a good descriptor for the gaseous and aqueous phases and allows catalysts to be categorized by reduction products. However, descriptors alone are insufficient for mapping in the aprotic phase, requiring the use of a microkinetic model.
Article
Engineering, Chemical
Sara Escorihuela, Fidel Toldra-Reig, Sonia Escolastico, Raul Murciano, Agustin Martinez, Jose Manuel Serra
Summary: By depositing a Cu-based protective layer on the surface of self-supported palladium tubular membranes, selective and controlled addition of H-2 can be achieved in Fischer-Tropsch synthesis, increasing hydrocarbon yield and reducing methane formation.
JOURNAL OF MEMBRANE SCIENCE
(2021)
Article
Chemistry, Physical
Wijnand Marquart, Shaine Raseale, Gonzalo Prieto, Anna Zimina, Bidyut Bikash Sarma, Jan-Dierk Grunwaldt, Michael Claeys, Nico Fischer
Summary: Four Mo-based catalysts prepared via three different synthesis techniques show high efficiency in CO2 activation, with oxidation of carbides only occurring at high temperatures and concentrations.
Article
Chemistry, Physical
Kai Jeske, Ali Can Kizilkaya, Ivan Lopez-Luque, Norbert Pfaender, Mathias Bartsch, Patricia Concepcion, Gonzalo Prieto
Summary: The discussion in the article revolves around the role of different catalysts in adjusting hydrocarbon product distributions. Cobalt catalysts are suitable for synthesizing long-chain paraffins, while iron carbide catalysts are suitable for co-producing waxes and liquid olefins. Oxides can influence the selectivity of catalysts, with alkali and lanthanide oxides decreasing the turnover frequency.
Article
Chemistry, Applied
G. M. Cabello Gonzalez, A. L. Villanueva Perales, M. Campoy, J. R. Lopez Beltran, A. Martinez, F. Vidal-Barrero
Summary: A kinetic model has been developed to describe the one-step conversion of ethanol into 1,3-butadiene over a mixed catalyst, taking into account the effect of water content on catalyst performance. The model, validated using experimental data, can predict the formation of major and minor compounds accurately, with room for improvement in predicting certain products. This modelling approach is expected to be applicable to other one-step catalysts.
FUEL PROCESSING TECHNOLOGY
(2021)
Article
Chemistry, Applied
G. M. Cabello Gonzalez, A. L. Villanueva Perales, A. Martinez, M. Campoy, F. Vidal-Barrero
Summary: This paper investigates key issues in the design of industrial ethanol to 1,3-butadiene two-step processes, with a focus on the performance of Ta-SBA-15 catalyst under different operating conditions and the influence of water on catalyst stability. The results reveal complex interacting effects between reaction conditions and emphasize the importance of careful selection to optimize catalyst performance.
FUEL PROCESSING TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Kai Jeske, Thorsten Roesler, Maurice Belleflamme, Tania Rodenas, Nico Fischer, Michael Claeys, Walter Leitner, Andreas J. Vorholt, Gonzalo Prieto
Summary: We report a method that integrates solid cobalt Fischer-Tropsch and molecular hydroformylation catalysts in tandem for selective conversion of syngas to higher alcohols. Catalyst engineering enables efficient overall transformation by bridging gaps in operation temperature and intrinsic selectivity. The results demonstrate that controlled cooperation between solid and soluble catalysts is a promising approach for selective conversion processes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Mercedes Boronat, Maria J. Climent, Patricia Concepcion, Urbano Diaz, Hermenegildo Garcia, Sara Iborra, Antonio Leyva-Perez, Lichen Liu, Agustin Martinez, Cristina Martinez, Manuel Moliner, Joaquin Perez-Pariente, Fernando Rey, Enrique Sastre, Pedro Serna, Susana Valencia
Summary: This article introduces the significant contributions of Prof. Avelino Corma in the field of heterogeneous catalysis and materials science. It highlights his remarkable achievements in areas such as solid catalysts, materials synthesis, and photochemistry. The article also emphasizes the importance of the research methods and paradigms developed by Avelino and his team in addressing new scientific challenges in building a sustainable world.
Article
Chemistry, Physical
Jaroslav Aubrecht, Violetta Pospelova, Agustin Martinez, Patricia Concepcion, Oleg Kikhtyanin, Petr Straka, David Kubicka
Summary: This study investigated the structural transformation of five CuZnAl catalysts with different Cu/Zn and Al/(Cu+Zn) atomic ratios. It was found that the catalyst with lower Cu loading exhibited higher activity after reduction.
APPLIED CATALYSIS A-GENERAL
(2022)
Article
Chemistry, Multidisciplinary
Marcos G. Farpon, Wilson Henao, Philipp N. Plessow, Eva Andres, Raul Arenal, Carlo Marini, Giovanni Agostini, Felix Studt, Gonzalo Prieto
Summary: A frontier challenge in single-atom catalysis is the design of fully inorganic sites that can emulate the high reaction selectivity of organometallic counterparts in homogeneous catalysis. Modulating the direct coordination environment in single-atom sites through the use of the oxide support's surface chemistry is a powerful strategy that has been underexplored. In this study, isolated Rh atoms stabilized on oxygen-defective SnO2 exhibited excellent TOF and nearly full selectivity in the gas-phase hydroformylation of ethylene, surpassing the thermodynamically favored olefin hydrogenation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Tania Rodenas, Gonzalo Prieto
Summary: Tandem catalysis is a technique that integrates two or more catalysts to achieve high specificity reactions under a single set of operation conditions. Single-atom catalysts have emerged as a promising platform for tandem catalysis. While recent experiments have showcased the potential of tandem (electro)catalytic processes based on single-atom catalysts, verifying the tandem nature of these processes remains a challenge.
Article
Nanoscience & Nanotechnology
Alberto Rodriguez-Gomez, Samy Ould-Chikh, Wilson Henao, Giovanni Agostini, Gonzalo Prieto, Jorge Gascon
Summary: A series of Pt-Fe catalysts supported on mesoporous silica SBA-15 were prepared and studied, showing high activity and selectivity. However, detrimental structural changes occurred after reaction-regeneration cycles, which could be minimized by reactivation.
ACS APPLIED NANO MATERIALS
(2023)
Article
Chemistry, Physical
Javier Castells-Gil, Samy Ould-Chikh, Adrian Ramirez, Rafia Ahmad, Gonzalo Prieto, Alberto Rodriguez Gomez, Luis Garzon-Tovar, Selvedin Telalovic, Lingmei Liu, Alessandro Genovese, Natalia M. Padial, Antonio Aguilar-Tapia, Pierre Bordet, Luigi Cavallo, Carlos Marti-Gastaldo, Jorge Gascon
Summary: Mixed-metal oxides have complex surface chemistry and high oxygen lattice mobilities, making them important materials. Modulating stoichiometry in mixed-metal oxides can tune optical and catalytic properties, although accessing different stoichiometries is not always possible synthetically.
Article
Chemistry, Physical
Shaine Raseale, Wijnand Marquart, Kai Jeske, Gonzalo Prieto, Michael Claeys, Nico Fischer
Summary: The study investigated the impact of Fe:Ni ratio and the Lewis acidity of a metal oxide support on the CO2-ODH reaction. FeNi catalysts were synthesized, where increasing Ni content led to higher activity and stability. The results suggest the need for a tandem catalyst system between a reducible oxide carrier and FeNi species.
FARADAY DISCUSSIONS
(2021)
Article
Chemistry, Physical
Sophia Mohammadnasabomran, Carlos Marquez-Alvarez, Joaquin Perez-Pariente, Agustin Martinez
Summary: Grafting aluminum onto SBA-15 improves Co dispersion and results in a more homogeneous distribution of metal species. However, the Al-grafted CoRu/Al-SBA-15 catalyst shows lower activity in Fischer-Tropsch synthesis compared to the all-silica CoRu/SBA-15 counterpart, but exhibits enhanced selectivity towards liquid hydrocarbons.
CATALYSIS SCIENCE & TECHNOLOGY
(2021)
Article
Chemistry, Physical
Bidyut B. Sarma, Giovanni Agostini, Marcos G. Farpon, Carlo Marini, Norbert Pfaender, Gonzalo Prieto
Summary: This study investigates the impact of high-temperature oxidative crystal redispersion and oxide atom-trapping phenomena on the synthesis and stability of bimetallic nanoclusters, demonstrating a route towards obtaining uniformly sized and stable bimetallic clusters through these mechanisms.
JOURNAL OF MATERIALS CHEMISTRY A
(2021)
Article
Chemistry, Physical
Yifan Sun, Ye Lv, Wei Li, Jinli Zhang, Yan Fu
Summary: In this study, PtRu electrocatalysts were fabricated on carbon paper via cyclic electrodeposition for the electrocatalytic hydrogenation (ECH) of phenol. The Pt3Ru3 catalyst exhibited excellent activity and stability for the conversion of phenol to cyclohexanol at ambient temperature and various current densities. The in situ Raman spectroscopy and kinetic study revealed the hydrogenation mechanism of phenol over Pt3Ru3 in acidic electrolyte, providing an effective electrochemical strategy for the facile construction of durable electrode materials and efficient phenol hydrogenation.
JOURNAL OF CATALYSIS
(2024)
Article
Chemistry, Physical
Amir Shahzad, Khezina Rafiq, Muhammad Zeeshan Abid, Naseem Ahmad Khan, Syed Shoaib Ahmad Shah, Raed H. Althomali, Abdul Rauf, Ejaz Hussain
Summary: Photocatalytic hydrogen production through water splitting is an effective method for meeting future energy demands. In this study, researchers synthesized a 1 % Ag2S/Cu2S co-doped CdZnS catalyst and found that it can produce hydrogen at a higher rate. The co-doping of Ag2S and Cu2S in the CdZnS catalyst showed a synergistic effect, with Ag2S promoting oxidation reactions and Cu2S promoting reduction reactions.
JOURNAL OF CATALYSIS
(2024)
