Article
Energy & Fuels
Wenli Lu, Jungang Wang, Zhongyi Ma, Congbiao Chen, Yan Liu, Bo Hou, Debao Li, Baojun Wang
Summary: The role of carbon deposits during Fischer-Tropsch synthesis (FTS) on cobalt catalysts is still debated. This study investigates the effects of pre-deposited composite and single carbon on cobalt catalysts in FTS. Different types of carbon deposits (atomic carbon, polymeric carbon, graphitic carbon) are identified and characterized using TPH, Raman, and XPS. Results show that the presence of pre-deposited carbon significantly affects the catalytic activity, methane selectivity, and stability of the Co-based catalysts in FTS.
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
Amel Cydric Ghogia, Bruno F. Machado, Simon Cayez, Ange Nzihou, Philippe Serp, Katerina Soulantica, Doan Pham Minh
Summary: The chemistry between the Co precursor and the support during catalyst preparation has a crucial impact on the catalyst properties, while the CNT surface chemistry also influences the characteristics of the catalyst. The study found an inverse correlation between Co particle size and activity, highlighting the importance of precursor/support couple in the structure and performance of Co/CNT catalysts.
JOURNAL OF CATALYSIS
(2021)
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
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
Kristina Mazurova, Aleksandr Glotov, Mikhail Kotelev, Oleg Eliseev, Pavel Gushchin, Maria Rubtsova, Anna Vutolkina, Ruslan Kazantsev, Vladimir Vinokurov, Anna Stavitskaya
Summary: A nanoarchitectural approach was used to load mesoporous halloysite nanotubes with RuCo nanoparticles for Fischer-Tropsch catalysis. The resulting catalyst exhibited high activity, low selectivity to methane and CO2, high selectivity to C5+ hydrocarbons, and a chain growth index of 0.853. The choice of reducing agent during synthesis played a crucial role in the reducibility and selectivity of the RuCo catalysts.
SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS
(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)
Review
Biochemistry & Molecular Biology
Maryam Jamaati, Mostafa Torkashvand, Saeedeh Sarabadani Tafreshi, Nora H. de Leeuw
Summary: This review summarizes the theoretical progress of active and selective catalysts for CO conversion to desirable products, focusing on the surface structure, surface coverage, temperature, and pressure effects on CO dissociation and hydrogenation.
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, Physical
Tshepo Molefe, Dean Barrett, Beatriz Diaz, Roy Forbes, Neil J. Coville
Summary: This study reports on the synthesis and application of osmium nanoparticles supported on and/or encapsulated in hollow carbon spheres for Fischer-Tropsch Synthesis (FTS). It is demonstrated that the interaction between osmium and cobalt has a significant effect on the catalyst activity when loaded together. Proximity of osmium and cobalt leads to higher FTS activity and C5+ production through the primary spillover effect. This study reveals the effect of osmium on FTS catalysts for the first time.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Physical
Mostafa Torkashvand, Saeedeh Sarabadani Tafreshi, Nora H. de Leeuw
Summary: The increasing demand for renewable fuels and sustainable products has led to the development of active and selective catalysts for the conversion of carbon monoxide. First-principles calculations based on density functional theory are used to investigate the Fischer-Tropsch synthesis over the Co (001) surface, revealing CH4 as the dominant product. Kinetic analysis shows that the hydrogenation of cis-HCOH has the lowest energy barrier for CH production, while the hydrogenation of CO to COH has the highest energy barrier.
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
Craig P. Plaisance, Rutger A. van Santen, Karsten Reuter
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2017)
Article
Chemistry, Physical
Chong Liu, Ionut Tranca, Rutger A. van Santen, Emiel J. M. Hensen, Evgeny A. Pidko
JOURNAL OF PHYSICAL CHEMISTRY C
(2017)
Editorial Material
Chemistry, Physical
Hans Niemantsverdriet, Pieter van Helden, Emiel Hensen, David Lennon, Katherine Holt, Graham Hutchings, Michael Bowker, Richard Catlow, Mzamo Shozi, Linda Jewell, Michael Claeys, James Hayward, Neil Coville, Nico Fischer, Alberto Roldan, Evjeniy Redekop, Thobani Gambu, Letisha Deeplal, Thabiso Perfect Oscar Mkhwanazi, Kees-Jan Weststrate, Detlef Bahnemann, Matthew Neurock, Hans Schulz, Ding Ma, Simon Kondrat, Paul Collier, Abhishek Kumar Gupta, Avelino Corma, Paul Akomeah, Enrique Iglesia, Eric van Steen, Nora de Leeuw, Moritz Wolf, Tracey van Heerden
FARADAY DISCUSSIONS
(2017)
Article
Chemistry, Physical
Rutger A. van Santen, Aditya Sengar, Erik Steur
FARADAY DISCUSSIONS
(2018)
Article
Chemistry, Physical
Rutger A. van Santen, Aditya Sengar, Erik Steur
FARADAY DISCUSSIONS
(2018)
Article
Chemistry, Physical
Aditya Sengar, Rutger A. van Santen, Erik Steur, Johannes A. M. Kuipers, Johan Padding
Article
Engineering, Chemical
A. Sengar, J. A. M. Kuipers, R. A. van Santen, J. T. Padding
CHEMICAL ENGINEERING SCIENCE
(2019)
Article
Chemistry, Applied
Pieter van Helden, Frans Prinsloo, Jan-Albert Van den Berg, Bongani Xaba, Willem Erasmus, Michael Claeys, Jan van de Loosdrecht
Article
Chemistry, Applied
Denzil Moodley, Michael Claeys, Eric van Steen, Pieter van Helden, Deshen Kistamurthy, Kees-Jan Weststrate, Hans Niemantsverdriet, Abdool Saib, Willem Erasmus, Jan van de Loosdrecht
Article
Chemistry, Physical
Aditya Sengar, Rutger A. van Santen, Johannes A. M. Kuipers
Article
Chemistry, Physical
Rudaviro Garidzirai, Phillimon Modisha, Innocent Shuro, Jacobus Visagie, Pieter van Helden, Dmitri Bessarabov
Summary: In this study, the effects of Mg and Zn dopants on the catalytic performance of Pt/Al2O3 catalyst for dehydrogenation of H18-DBT were investigated. The results showed that Pt/Mg-Al2O3 exhibited the highest average hydrogen flowrate and hydrogen yield, demonstrating improved catalytic performance compared to Pt/Zn-Al2O3 and Pt/Al2O3.
Article
Multidisciplinary Sciences
Charlotte Vogt, Florian Meirer, Matteo Monai, Esther Groeneveld, Davide Ferri, Rutger A. van Santen, Maarten Nachtegaal, Raymond R. Unocic, Anatoly I. Frenkel, Bert M. Weckhuysen
Summary: In this study, structure insensitivity in catalysis was found to be linked to reaction-dependent particle size dependent restructuring. We observed particle size-dependent effects such as restructuring during ethene hydrogenation, which increased with increasing particle size, while no such effects were observed during CO2 hydrogenation. Additionally, we demonstrated that the rate of carbon diffusion on and into nanoparticles increases with particle size.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Physical
I. Tezsevin, R. A. van Santen, I. Onal
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2018)
Article
Physics, Fluids & Plasmas
A. Sengar, J. A. M. Kuipers, Rutger A. van Santen, J. T. Padding
Article
Physics, Fluids & Plasmas
Barry W. Fitzgerald, Johan T. Padding, Rutger van Santen
Article
Chemistry, Physical
Erhao Gao, Wenjing Feng, Qi Jin, Li Han, Yi He
Summary: The influence of K-doping on the reactive oxygen species and elementary reactions of HCHO catalytic oxidation was investigated using density functional theory (DFT). The introduction of K-doping changed the electronic structures of Ce and O, facilitating the adsorption and activation of HCHO and O2 molecules, enhancing lattice oxygen mobility, and reducing the energy barrier for HCHO oxidation. K-doping also promoted the formation of hydroxyl groups, facilitating HCHO adsorption and oxidation.
Article
Chemistry, Physical
Hao Fu, Zhangliang Xu
Summary: In this study, the adsorption mechanisms and detection performance of formaldehyde, ammonia, and sulfur dioxide on undoped and metal-doped ZnO surfaces were investigated using density functional theory. The results showed that formaldehyde and ammonia were physically adsorbed on the undoped ZnO surface, while sulfur dioxide was weakly chemisorbed. The adsorption energy was enhanced when ZnO was doped with metals. These findings provide theoretical guidance for the application of ZnO substrate materials in gas sensitivity research.
Article
Chemistry, Physical
Atsushi Nomura, Tohru Kurosawa, Migaku Oda, Satoshi Demura, Shogo Kuwahara, Sora Kobayashi, Hideaki Sakata
Summary: The study investigates the tunneling spectra of 1T-TiSe2 in the CDW state and the dip structure below the Fermi level, aiming to determine whether this dip is a CDW gap. The answer to this question is crucial for understanding the driving mechanism of CDW.
Article
Chemistry, Physical
A. S. Petrov, D. I. Rogilo, A. I. Vergules, V. G. Mansurov, D. V. Sheglov, A. V. Latyshev
Summary: This study investigates Si mass transport and morphological transformations on the Si(111) surface during (root 3 x root 3)-Sn reconstruction formation and Si homoepitaxy. The research shows that the formation of different Sn phases at different temperatures affects the Si island nucleation and monatomic step shift, which in turn impact the morphology of the Sn/Si(111) interface. Electromigration-induced drift of disordered Sn domains leads to enhanced noncompensated Si mass transport and surface roughening.
Article
Chemistry, Physical
D. V. Gruznev, L. V. Bondarenko, A. Y. Tupchaya, A. A. Yakovlev, A. N. Mihalyuk, A. V. Zotov, A. A. Saranin
Summary: Deposition of thallium (Tl) onto the Au/Si(111)5 x 2 reconstruction followed by annealing results in the formation of a surface structure with 4 x 2 periodicity. The immiscibility of Au and Tl leads to the migration of Tl atoms over the Si chains. Thallium donates electrons to the surface, converting the metallic surface into an insulating state and altering the inter-chain distance within the array of Au atomic wires.
Article
Chemistry, Physical
Simone Giusepponi, Francesco Buonocore, Barbara Ferrucci, Massimo Celino
Summary: Using ab-initio calculations, the interaction between lead adatom and both clean and doped iron (100) surfaces was investigated. It was found that the lead adatom prefers to adsorb in the hollow site, which is more stable compared to the top and bridge sites, and in this position, it is energetically favorable over the iron adatom. Moreover, lead adsorbed in the hollow site of the iron (100) surface doped with chromium was found to create a more stable system compared to nickel-doped surfaces with an iron adatom in the same position. The study also explored inter-layer distances, bonding mechanisms, magnetic behaviors, and charge density differences. The results provide insights into the role of doping in the interaction between lead adatom and iron surface, and have implications for the analysis of corrosion processes caused by liquid lead.
Article
Chemistry, Physical
Shuo Zhang, Jin-Ho Choi
Summary: The recent synthesis of two-dimensional layered WSi2N4 has attracted attention due to its potential applications. This study investigates the catalytic performance of WSi2N4 monolayers with nitrogen vacancies in the hydrogen evolution reaction using first-principles calculations. The results show that the defective WSi2N4 monolayers exhibit remarkably high catalytic activity comparable to platinum catalysts. Electronic structure calculations also reveal the emergence of spin-polarized states due to the introduction of nitrogen vacancies.
Article
Chemistry, Physical
Xiaoyan Yu, Xin Cao, Wei Kang, Shanhua Chen, Ao Jiang, Yuhao Luo, Wenwei Deng
Summary: First-principles calculations were used to investigate the electronic properties of a TiO2 heterostructure modified with Bi2Te3 co-catalyst. The study revealed that the Bi2Te3/TiO2 interface introduced optimal band offsets, effectively suppressing electron-hole recombination and enhancing the utilization efficiency of photo-generated carriers. Additionally, the Bi2Te3 co-catalyst introduced extra catalytic active sites, further boosting the photo-catalytic hydrogen evolution efficiency.
Article
Chemistry, Physical
Filippo Longo, Emanuel Billeter, Selim Kazaz, Alessia Cesarini, Marin Nikolic, Aarati Chacko, Patrik Schmutz, Zbynek Novotny, Andreas Borgschulte
Summary: Alkaline water electrolysis is a simple and efficient method for renewable hydrogen production, utilizing cheap and abundant transition metals. The catalytic properties of Ni materials are enhanced by the formation of oxidized compounds on the surface. The high electrocatalytic activity of Ni (oxy)-hydroxides is directly related to water intercalation in the passivation layer, supporting the hypothesis of a water mediated OH- diffusion mechanism. The self-organization of the surface structure during passivation layer formation enables high electrode performance.
Article
Chemistry, Physical
Mohan Kumar Kuntumalla, Miriam Fischer, Alon Hoffman
Summary: By investigating the bonding, retention, and thermal stability of nitrogen in H-Diamond (100), it was found that nitrogen can partially recover its bonding with carbon atoms after high-temperature annealing, indicating a high thermal stability of nitrogen in diamond.
Article
Chemistry, Physical
Dong Yue, Liangying Wen, Rong Chen, Jianxin Wang, Zhongqing Yang
Summary: The adsorption behavior of Cl2 molecules on the TiC surface and the formation and transfer of reaction products were studied using first-principles ab initio calculations. The results show that the Cl atoms bonded to the surface Ti atoms are more stable, and the TiCl3 intermediate is easier to form than the TiCl2 intermediate.
Article
Chemistry, Physical
Yatao Wang, Peng Zhang, Hongjuan Li, Qiuju Xu, Shujun Liu, Xiaopeng Liu, Xuehua Guo, Yitao Li, Jinzhang Liu, Sen Dong, Zhi Wei Seh, Qianfan Zhang
Summary: In this study, the adsorption performance of two types of metal-organic frameworks (MOFs) for thiophene and benzene was experimentally investigated. The results showed that IZE-1 exhibited high selectivity and superior adsorption capacity for thiophene, especially at low concentrations. First-principles calculations and molecular dynamics simulations provided insights into the mechanism of thiophene adsorption and the high selectivity observed. This research demonstrates the potential of MOFs for thiophene adsorption, particularly at high concentrations.
