Article
Chemistry, Physical
Mikhail Shipilin, David Degerman, Patrick Lomker, Christopher M. Goodwin, Gabriel L. S. Rodrigues, Michael Wagsta, Joergen Gladh, Hsin-Yi Wang, Andreas Stierle, Christoph Schlueter, Lars G. M. Pettersson, Anders Nilsson, Peter Amann
Summary: In this study, the effect of pressure, temperature, time, and gas feed composition on the growth dynamics of iron-carbon phases was investigated. The details of iron surface carburization and product formation under realistic conditions were revealed using a combination of experimental and theoretical approaches. This research provides important insights into the relationship between the catalyst's surface and the reaction.
Article
Chemistry, Physical
Mikhail Shipilin, David Degerman, Patrick Loemker, Christopher M. Goodwin, Gabriel L. S. Rodrigues, Michael Wagstaffe, Jorgen Gladh, Hsin-Yi Wang, Andreas Stierle, Christoph Schlueter, Lars G. M. Pettersson, Anders Nilsson, Peter Amann
Summary: This study investigates the detailed mechanism of carbide formation on iron-based catalysts and the effect of reaction conditions on the catalyst surface state through experiments and theoretical calculations.
Article
Chemistry, Physical
Fangxu Lu, Xin Chen, Zhigang Lei, Lixiong Wen, Yi Zhang
Summary: Research on iron-based catalysts doped with SiO2 or Al2O3 has shown that adjusting the formation of iron carbides can enhance the activity of Fischer-Tropsch synthesis reactions. Characterization results using techniques such as XPS and CO-DRIFTS revealed that SiO2 or Al2O3 affects the electronic state of iron atoms and promotes the formation of Fe-Si or Fe-Al interactions on the surface of iron powder, which in turn plays a key role in the formation of the active phase ε-Fe2C. The content of ε-Fe2C is found to be more beneficial to activity compared to the traditionally recognized active phase χ-Fe5C2 in Fischer-Tropsch synthesis reactions.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
Article
Chemistry, Physical
Luke M. van Koppen, A. Iulian Dugulan, G. Leendert Bezemer, Emiel J. M. Hensen
Summary: This study explored the role of manganese as a structural promoter on silica-supported cobalt nanoparticles under high CO conversion conditions. It was found that adding manganese oxide enhanced the dispersion of cobalt but resulted in cobalt silicate formation. Without manganese, the cobalt particles sintered and transformed into cobalt carbide.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Seunghee Cha, Heewon Kim, Hyunkyung Choi, Chul Sung Kim, Kyoung-Su Ha
Summary: Chi-Fe5C2, a highly active phase in Fischer-Tropsch synthesis, was successfully synthesized using a wet-chemical route without the need for pre-activation. The encapsulation of chi-Fe5C2 nanoparticles with mesoporous silica was found to effectively protect them from deactivation and re-oxidation, while maintaining their phase intact. The CO2 selectivity of stabilized chi-Fe5C2 was very low, indicating its potential as a catalyst for Fischer-Tropsch synthesis.
Article
Chemistry, Physical
Xin-Pu Fu, Wen-Zhu Yu, Chao Ma, Jun Lin, Shi-Qi Sun, Shan-Qing Li, Pu-Ning Ren, Feng-Yan Jia, Meng-Yuan Li, Wei-Wei Wang, Xu Wang, Chun-Jiang Jia, Ke Wu, Rui Si, Chun-Hua Yan
Summary: The study successfully synthesized phase-pure Fe2N nanoparticles on Al2O3, achieving effective phase transformation to Fe2C and demonstrating high catalytic activity and selectivity.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
Article
Chemistry, Physical
Andrey S. Skrypnik, Qingxin Yang, Alexander A. Matvienko, Victor Yu Bychkov, Yuriy P. Tulenin, Henrik Lund, Sergey A. Petrov, Ralph Kraehnert, Aleks Arinchtein, Jana Weiss, Angelika Brueckner, Evgenii Kondratenko
Summary: This study provides fundamental knowledge for developing Fe-based catalysts for CO2 hydrogenation to higher hydrocarbons, with well-defined compositions prepared through controlled decomposition of iron oxalate. The research also elucidates the pathways from CO2 to CO, CH4, and higher hydrocarbons, establishing a correlation between reaction pathways and steady-state composition for tailored catalyst design and preparation. The best performing Fe-based catalyst achieves a selectivity to CH4 below 10%, with a selectivity to C2+-hydrocarbons around 50% at 25% CO2 conversion and 300 degrees C, with an olefin to paraffin ratio of 5.5 among C-2-C-4 hydrocarbons.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
Article
Chemistry, Physical
Fangxu Lu, Jielang Huang, Qing Wu, Yi Zhang
Summary: The interaction of Fe-Mn and promotion of electron transfer from MnO2 to Fe2O3 facilitate the formation of C-poor theta-Fe3C, enriching the reactivity for syngas to light olefins. Characterization techniques confirmed the impact of these interactions, providing valuable insights into the role of iron carbides in Fischer-Tropsch synthesis.
APPLIED CATALYSIS A-GENERAL
(2021)
Article
Chemistry, Physical
Ana Katiuce Fellenberg, Ahmed Addad, Jingping Hong, Pardis Simon, Yuliia Kosto, Bretislav Smid, Gang Ji, Andrei Y. Khodakov
Summary: This study revealed the migration of iron and copper species in bimetallic catalysts, enhancing the generation of iron active sites and interaction with promoter, resulting in higher activity.
JOURNAL OF CATALYSIS
(2021)
Article
Multidisciplinary Sciences
Mingrui Wang, Peng Wang, Guanghui Zhang, Zening Cheng, Mengmeng Zhang, Yulong Liu, Rongtan Li, Jie Zhu, Jianyang Wang, Kai Bian, Yi Liu, Fanshu Ding, Thomas P. Senftle, Xiaowa Nie, Qiang Fu, Chunshan Song, Xinwen Guo
Summary: In this study, an in situ synthesized K-Co2C catalyst was developed for CO2 hydrogenation, achieving a selectivity of 67.3% for C2+ hydrocarbons. Experimental and theoretical results showed that CoO transformed into Co2C, and the stability of Co2C depended on the reaction atmosphere and the K promoter. The formation of surface C* species was facilitated by the co-action of K promoter and H2O, while the adsorption of C* on CoO was enhanced by the K promoter. The addition of H2O extended the lifetime of K-Co2C from 35 hours to over 200 hours.
Article
Chemistry, Physical
Richard Gubo, Pengju Ren, Xin Yu, Tianfu Zhang, Xiaodong Wen, Yong Yang, Yong-Wang Li, J. W. (Hans) Niemantsverdriet, C. J. (Kees-Jan) Weststrate
Summary: The relationship between structure, electronic properties, and stability of thin FCC (100) iron and cobalt carbide films prepared on Cu(1 0 0) was studied. The first experimental confirmation of the C-induced clock reconstruction on the FCC(1 0 0) surfaces of iron and cobalt was presented. Both Fe and Co surface carbides exhibited a p4g (2 x 2) surface reconstruction with tetracoordinated square planar carbon and pure FCC (100) metal layers underneath. Detailed electronic and structural models for Fe2C and Co2C p4g (2 x 2) surface carbides and other 2D Fe2X interstitial compound systems were provided using AR-XPS, AES, LEED, STM, and theoretical calculations.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Deizi Peron, Alan J. Barrios, Alan Taschin, Iulian Dugulan, Carlo Marini, Giulio Gorni, Simona Moldovan, Siddardha Koneti, Robert Wojcieszak, Joris W. Thybaut, Mirella Virginie, Andrei Y. Khodakov
Summary: The study found that antimony and tin have strong promoting effects on silica supported iron Fischer-Tropsch catalysts, significantly increasing the reaction rate and improving catalyst stability. The addition of these elements through impregnation can increase the intrinsic activity of iron surface sites by 7-10 times without affecting iron dispersion.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
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
Chemistry, Physical
Jose G. Moya-Cancino, Ari-Pekka Honkanen, Ad M. J. van der Eerden, Ramon Oord, Matteo Monai, Iris ten Have, Christoph J. Sahle, Florian Meirer, Bert M. Weckhuysen, Frank M. F. de Groot, Simo Huotari
Summary: The study presents in situ experiments to investigate the formation of cobalt carbides during Fischer-Tropsch synthesis on a Co/TiO2 catalyst under relevant pressure and temperature conditions. X-ray Raman scattering (XRS) spectroscopy and X-ray diffraction (XRD) were used in combination to perform the experiments. The results indicate a change in the oxidation state of cobalt nanoparticles, leading to the formation of cobalt carbide (Co2C) during the FTS reaction.
Article
Chemistry, Physical
Jiachun Chai, Robert Pestman, Wei Chen, Noortje Donkervoet, A. Iulian Dugulan, Zhuowu Men, Peng Wang, Emiel J. M. Hensen
Summary: 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 C-13-labeled synthesis gas. It was found that in the initial stages, C diffused rapidly into the lattice, and the FT reaction started during this period. When reaching steady state, the diffusion rates of C in and out of the lattice converged, and the FT reaction continued via two parallel reaction mechanisms. The outer layers of the Fe carbide were involved in hydrocarbon formation via a slow reaction, contributing to around 10% of the total activity.
Article
Chemistry, Physical
Muthu Kumaran Gnanamani, Gary Jacobs, Michela Martinelli, Wilson D. Shafer, Shelley D. Hopps, Gerald A. Thomas, Burtron H. Davis
Article
Chemistry, Physical
Muthu Kumaran Gnanamani, Hussein H. Hamdeh, Wilson D. Shafer, Shelley D. Hopps, Burtron H. Davis
APPLIED CATALYSIS A-GENERAL
(2018)
Article
Chemistry, Physical
Muthu Kumaran Gnanamani, Michela Martinelli, Sandeep Badoga, Shelley D. Hopps, Burtron H. Davis
Article
Chemistry, Applied
Mauro C. Ribeiro, Muthu K. Gnanamani, Richard Garcia, Gary Jacobs, Raimundo C. Rabelo-Neto, Fabio B. Noronha, Igor F. Gomes, Burtron H. Davis
Article
Chemistry, Physical
Wilson D. Shafer, Muthu Kumaran Gnanamani, Uschi M. Graham, Jia Yang, Cornelius M. Masuku, Gary Jacobs, Burtron H. Davis
Article
Chemistry, Multidisciplinary
Charles Beasley, Muthu Kumaran Gnanamani, Michela Martinelli, Kinga Gora-Marek, Kaichiro Hamano, Wilson D. Shafer, Namal Wanninayake, Doo Young Kim
Article
Chemistry, Physical
Harrison Williams, Muthu K. Gnanamani, Gary Jacobs, Wilson D. Shafer, David Coulliette
Article
Chemistry, Multidisciplinary
Charles Beasley, Muthu Kumaran Gnanamani, Eduardo Santillan-Jimenez, Michela Martinelli, Wilson D. Shafer, Shelley D. Hopps, Namal Wanninayake, Doo-Young Kim
Article
Chemistry, Physical
Muthu Kumaran Gnanamani, Richard Garcia, Gary Jacobs, Kinga Gora-Marek, Donald C. Cronauer, A. Jeremy Kropf, Christopher L. Marshall
APPLIED CATALYSIS A-GENERAL
(2020)
Article
Chemistry, Physical
Michela Martinelli, Muthu Kumaran Gnanamani, Steve LeViness, Gary Jacobs, Wilson D. Shafer
APPLIED CATALYSIS A-GENERAL
(2020)
Article
Energy & Fuels
Sandeep Badoga, Muthu Kumaran Gnanamani, Michela Martinelli, Dennis E. Sparks, Wenping Ma
Article
Chemistry, Multidisciplinary
Charles Beasley, Muthu Kumaran Gnanamani, Dali Qian, Shelley D. Hopps
Summary: The optimal loading of Pd/TiO2 catalyst for photocatalytic reforming of sucrose and dextrose is around 0.5-1.0 wt%, with higher or lower Pd content not beneficial for hydrogen production. Kinetic studies conducted under the Langmuir-Hinshelwood (LH) mechanism show that metallic Pd enhances the rate of hydrogen evolution.
Article
Chemistry, Physical
Muthu Kumaran Gnanamani, Gary Jacobs, Wilson D. Shafer, Michela Martinelli, Donald C. Cronauer, A. Jeremy Kropf, Christopher L. Marshall, Burtron H. Davis
APPLIED CATALYSIS A-GENERAL
(2017)
Article
Chemistry, Physical
Gary Jacobs, Venkat Ramana Rao Pendyala, Michela Martinelli, Wilson D. Shafer, Muthu Kumaran Gnanamani, Syed Khalid, Aimee MacLennan, Yongfeng Hu, Burtron H. Davis