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
Engineering, Chemical
Imaad Davies, Klaus P. Moller
Summary: The kinetics of n-paraffin and 1-olefin formation in the Fischer-Tropsch reaction system are equilibrium-limited, allowing for an effective description of product distribution and observed reaction behavior trends. The model preserves the polymerization character of the reaction and successfully describes the dominant trends in product distribution as a function of CO conversion, temperature, and pressure.
CHEMICAL ENGINEERING SCIENCE
(2021)
Article
Engineering, Chemical
Arash Yahyazadeh, Philip Boahene, Tolu Emiola-Sadiq, Ajay K. Dalai, Lifeng Zhang
Summary: The kinetics of the Fischer-Tropsch (FT) reaction was studied on a KMo bimetallic promoted Fe catalyst supported on carbon nanotubes (CNTs). The mechanism of CO activation and the rate equation for CO consumption during FT reactions were investigated. Fresh and spent catalysts were characterized to evaluate the synergistic effects of Fe, Mo, and K phases on catalyst activity. The best fit kinetic model based on carbide formation approach was identified. The effects of reaction temperature and pressure on Fischer-Tropsch synthesis product distribution were assessed, and the kinetic model was compared with the Anderson-Schulz-Flory model.
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
(2023)
Article
Chemistry, Physical
Yanping Chen, Lixuan Ma, Riguang Zhang, Runping Ye, Wei Liu, Jiatong Wei, Vitaly V. Ordomsky, Jian Liu
Summary: This study reports the design of a low-cost and scalable carbon-supported iron catalyst (K-Fe/NC) with tunable alcohol selectivity in Fischer-Tropsch synthesis. The catalyst exhibits a core-shell structure and facilitates the investigation of iron structural evolution. The dissociation and association of CO are thoroughly verified through theoretical calculations and experimental reactions. The synergistic effect between chi-Fe5C2/epsilon-Fe2C and Fe3O4 dual active sites is proposed as the mechanism for alcohol formation.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2022)
Article
Chemistry, Multidisciplinary
Maria Batuecas, Richard Y. Kong, Andrew J. P. White, Mark R. Crimmin
Summary: Selective reactions that combine H-2, CO, and organic electrophiles to form hydrogenated C-3 and C-4 carbon chains have been reported. These reactions involve CO homologation mediated by [W(CO)(6)] and an aluminum(I) reductant, followed by functionalization and hydrogenation of the chain ends. Kinetics and DFT calculations provide insight into the hydrogenation of a metal-locarbene intermediate, revealing the controlled production of well-defined products with desired chain length and functionality.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Minhua Zhang, Haipeng Yu, Yingzhe Yu, Lingtao Wang
Summary: This study investigates the catalytic behavior of cobalt carbide nanoprisms in the Fischer-Tropsch to olefins (FTO) process. The results show that C-O scission and CHO insertion play important roles in ethylene formation and carbon chain growth, while the selectivity towards oxygenates is suppressed.
JOURNAL OF CATALYSIS
(2022)
Article
Energy & Fuels
Mei Yang, Gang Wang, Jian-Nian Han, Cheng-Di Gao, Jin-Sen Gao
Summary: To produce low olefin gasoline with high octane number, operating conditions were optimized in a Fischer-Tropsch (F-T) wax fluid catalytic cracking (FCC) unit. Experimental results showed that under specific conditions, the olefin content in gasoline could be reduced while causing a loss in octane number. To address this issue, a novel FCC process using a turbulent fluidized bed (TFB) reactor was proposed, which improved the reduction of olefins and the increase of aromatics. Although there was a decrease in gasoline yield, the aromatic content and octane number were significantly improved.
Article
Engineering, Chemical
Umesh Pandey, Anders Runningen, Ljubisa Gavrilovic, Erik A. Jorgensen, Koteswara R. Putta, Kumar R. Rout, Erling Rytter, Edd A. Blekkan, Magne Hillestad
Summary: The detailed kinetic model developed in this study accurately describes the consumption of key components and product distribution in the Fischer-Tropsch synthesis over a commercial catalyst, incorporating a water-assisted CO dissociation mechanism and a novel approach to product distribution modeling. The model parameters are optimized against experimental data under various process conditions, showing a good fit with literature reported values. The model can accurately capture the effects of water and other process variables on the kinetics and product distribution, crucial for the design and optimization of Fischer-Tropsch reactors.
Article
Chemistry, Multidisciplinary
Nabil Majd Alawi, Firas Khaleel AL-Zuhairi, Hoang M. Nguyen, Hassan H. Al-Mohammedawi, Jamal M. Ali
Summary: This study investigates the kinetics of the Fischer-Tropsch process synthesis using feedstocks from biogas. The results show that a simple model can accurately describe the reaction kinetics under different working conditions.
Article
Chemistry, Physical
Jiachun Chai, Robert Pestman, Wei Chen, A. Iulian Dugulan, Bo Feng, Zhuowu Men, Peng Wang, Emiel J. M. Hensen
Summary: The formation of Fe-carbide phases is crucial for Fischer-Tropsch synthesis catalysts. Carburization of Raney Fe showed that CO dissociation occurs at -150 degrees C, while C diffusion into metallic Fe requires higher temperature. The carburization rate increases with H2/CO ratio, leading to predominant formation of carbon-rich ε'-carbide.
JOURNAL OF CATALYSIS
(2021)
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
Chi Zhang, Xiurong Yang, Zihan Zhang, Jiachen Li, Wujing Jin, Haixia Ma
Summary: In this study, the decomposition mechanism of ammonium perchlorate (AP) on graphitic carbon nitride (g-C3N4) catalyst was investigated using density functional theory calculation. The main decomposition pathway of AP was found to be HClO4 -> ClO3- -> ClO2- -> ClO- -> Cl-. Additionally, the oxidation of g-C3N4 surface weakened its catalytic capacity for AP decomposition but enhanced its catalytic capacity for the adsorption and dehydrogenation of NH3.
SURFACES AND INTERFACES
(2022)
Review
Chemistry, Multidisciplinary
Neil K. Razdan, Ting C. Lin, Aditya Bhan
Summary: The net rate of a reversible chemical reaction is determined by the difference in rates between the forward and reverse reaction paths. In a multi-step reaction, the forward and reverse trajectories are not simply the reverse of each other, but consist of distinct rate-controlling steps, intermediates, and transition states. Traditional rate descriptors do not provide intrinsic kinetic information, but instead combine unidirectional contributions based on the occurrence of forward and reverse reactions and thermodynamics. This review aims to provide analytical and conceptual tools to separate and identify the contributions of reaction kinetics and thermodynamics in reversible reaction systems.
Article
Energy & Fuels
Wei Zhao, Jingjing Wang, Kunpeng Song, Zhi Xu, Liping Zhou, Hongwei Xiang, Xu Hao, Yong Yang, Yongwang Li
Summary: The study focuses on investigating the effects of operating conditions on the catalytic cracking performance of FTS wax using an industrial beta-zeolite based catalyst in a riser reactor, and developing an eight-lumped kinetic model for product selectivity description and simulation. The theoretical prediction aligns well with experimental data, providing valuable insights for reactor scale-up and operating condition optimization in the process.
Article
Chemistry, Physical
Zhengjia Li, Danmeng Yu, Linyan Yang, Jie Cen, Kang Xiao, Nan Yao, Xiaonian Li
Summary: The Ce promoters provided oxygen to the surface Co sites, reducing surface energy and influencing the formation of Co2C, thereby affecting product selectivity.
Article
Chemistry, Physical
Alireza Asiaee, Kenneth M. Benjamin
JOURNAL OF CHEMICAL PHYSICS
(2016)
Article
Chemistry, Physical
Kenneth M. Benjamin, Alireza Asiaee, Carrie Veer, Casey Losinski, Samuel Gunderson, Trevor Larson
JOURNAL OF PHYSICAL CHEMISTRY C
(2016)
Article
Chemistry, Physical
Alireza Asiaee, Kenneth M. Benjamin
MOLECULAR CATALYSIS
(2017)
Article
Thermodynamics
Alireza Asiaee, Sona Raeissi, Alireza Shariati
JOURNAL OF CHEMICAL THERMODYNAMICS
(2011)
Article
Energy & Fuels
M. R. Rahimpour, A. Ghorbani, A. Asiaee, A. Shariati
JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING
(2011)
Article
Chemistry, Physical
Alireza Asiaee, Sasan Nouranian, Shan Jiang, Alexander M. Lopez, Michael R. Fiske, Jennifer E. Edmunson, Eric T. Fox, William F. Kaukler, Hunain Alkhateb
JOURNAL OF MOLECULAR LIQUIDS
(2020)
Article
Chemistry, Physical
Sasan Nouranian, Alireza Asiaee, Farzin Rahmani, Shan Jiang, Alexander M. Lopez, Michael R. Fiske, Jennifer E. Edmunson, Eric T. Fox, William F. Kaukler, Hunain Alkhateb
Summary: This study used classical molecular dynamics simulations to investigate the solvation thermodynamics and structures of potential cationic and anionic species from Martian regolith in two ionic liquids. The research found that the solvation free energies (SFEs) of cationic solutes increase with ion valency and size, while the trends for anionic solutes are more complex due to molecular size and charge. Additionally, temperature had mixed effects on the solvation of cationic solutes, with higher temperatures generally favoring the dissolution of anionic solutes in both ionic liquids.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Chemistry, Physical
Haojie Li, Bingke Yang, Zhen Yao, Xuetao Wang, Kaiming Shen, Mengjie Liu
Summary: This study systematically investigates the influence of metal and nonmetal element doping on the photochemical properties of g-C3N4 for efficient catalytic AB hydrogen production. It provides a design method for high performance bifunctional catalysts of photocatalysis and metal catalysis. The results show that both non-metals (B, P) and metals (Ru, Ni) have efficient regulatory effects on the band structure of g-C3N4, resulting in a reduced band gap and improved hydrogen production. The study offers a theoretical method for the coupling of metal catalysis/photocatalysis ammonia borane to produce hydrogen.
MOLECULAR CATALYSIS
(2024)
Article
Chemistry, Physical
Shrouq Mujahed, Davide Gandolfo, Luigi Vaccaro, Evgueni Kirillov, Dmitri Gelman
Summary: In this study, a high-valent Ru(IV) bifunctional catalyst was successfully applied for the hydrosilylation of various functional groups. The high-valent hydride complexes showed high chemoselectivity and affinity towards reducing polar bonds. The scope, limitations, and plausible mechanism of the reaction were described.
MOLECULAR CATALYSIS
(2024)
Article
Chemistry, Physical
Yongzhen Peng, Kongchen Xia, Qi Wu
Summary: In this study, we report an engineered cyclohexanone monooxygenase that can be used for the asymmetric synthesis of chiral alpha-deuterated carbonyl compounds via enantioselective reductive dehalogenation. The engineered enzyme exhibits good chemoselectivity, stereoselectivity, and d-incorporation, making it a promising method for the synthesis of deuterated drugs.
MOLECULAR CATALYSIS
(2024)
Article
Chemistry, Physical
Qi Yang, Ruixuan Xu, Hongqi Nie, Qilong Yan, Jun Liu, Jiuyu Chen, Yunlan Sun
Summary: The adsorption and decomposition processes of ammonium perchlorate (AP) on pure-Al and Al2O3/Al surfaces were investigated using density functional theory. The results showed that the pure-Al surface is more conducive to the decomposition of AP and the activation of NH3, while the Al2O3/Al surface promotes the disengagement of H and NH3 decomposition.
MOLECULAR CATALYSIS
(2024)
Article
Chemistry, Physical
Yudong Hu, Guochao Xu, Ye Ni
Summary: This study identified a novel phenylalanine dehydrogenase (QtPDH) with high catalytic efficiency and thermal stability, making it a promising biocatalyst for industrial production of bulky aromatic primary amines. QtPDH exhibited a broader substrate specificity and significantly longer half-life compared to BbPDH.
MOLECULAR CATALYSIS
(2024)
Article
Chemistry, Physical
Weiling Zhao, Zhiling Huang, Hui Shen, Xianglong Li, Shaofen Zhao, Bo Xie, Shengjie Xia
Summary: This study investigated the effects of metal doping and crystal plane selection on the CO2 adsorption properties of MgO using density functional theory (DFT) methods. The results showed that the appropriate crystal plane and metal doping can improve the adsorption properties of MgO on CO2. The influence of different crystal planes and metal dopants on CO2 adsorption properties varied significantly. The research provides some references for experimental studies on CO2 adsorption by MgO by combining the dual modification of crystal plane and doped metal.
MOLECULAR CATALYSIS
(2024)
Article
Chemistry, Physical
Jie Zhang, Jinwei Chen, Zongbo Shi, Junyu Zhao, Runsheng Zhuo, Ruilin Wang
Summary: In this study, a double-layered silicalite-1 support with high specific surface area was synthesized, and a magnesium modification strategy was adopted to improve the catalytic activity and stability of the zinc-based catalyst. The modified catalyst showed enhanced propylene selectivity and anti-coking property.
MOLECULAR CATALYSIS
(2024)
Article
Chemistry, Physical
Pei-Sen Gao, Chang-Wang Pan, Cheng Liu, Wen -Tong Chen
Summary: Asymmetric electrocatalysis offers a unique approach to obtain enantioenriched molecules that are difficult to obtain through conventional methods. This study developed a novel bifunctional electrocatalyst, enabling the oxidative kinetic resolution of chiral 1,4-diols and gamma-lactones. The work demonstrates the potential of bifunctional electrocatalysis for asymmetric synthetic methods and its importance in the development of novel electrocatalytic methods.
MOLECULAR CATALYSIS
(2024)
Article
Chemistry, Physical
Qinzhe Lin, Xuanjin Lv, Xianming Zeng, Mengning Zhong, Qiyun Wu, Huilin Ren, Shenpeng Xu, Wentian Chen, Wenting Du, Jun Li
Summary: The catalytic efficiency of engineered IRED M5 was found to be relatively low when tasked with a bulky amine substrate. Rational design led to the mutants M203V and F260A, with F260A exhibiting a substantial improvement in conversion and stereoselectivity. The study revealed the potential molecular mechanisms underlying the effect of F260A and M203V on catalytic performance.
MOLECULAR CATALYSIS
(2024)
Article
Chemistry, Physical
Zhishuai Wang, Fengyun Su, Hailong Cao, Mengzhen Tian, Xiang Li, Haiquan Xie, Xiaoli Jin, Zhengdao Li, Xin Ying Kong
Summary: In this study, the efficiency of photocatalytic CO2 reduction was significantly enhanced by incorporating nickel oxide onto niobium pentoxide. The resulting catalyst showed remarkable methane and carbon monoxide production improvements.
MOLECULAR CATALYSIS
(2024)
Article
Chemistry, Physical
A. Yu. Sidorenko, Yu. M. Kurban, T. V. Khalimonyuk, I. V. Il'ina, N. S. Li-Zhulanov, O. S. Patrusheva, V. V. Goltsova, M. P. Bei, Zh. V. Ihnatovich, J. Warna, K. P. Volcho, N. F. Salakhutdinov, D. Yu. Murzin, V. E. Agabekov
Summary: This study provides a comprehensive investigation into the catalytic condensation of renewable 3-carene with formaldehyde for the one-step preparation of terpenoid trans-4-hydroxymethyl-2-carene. Various acids and alumino-silicates were found to catalyze the reaction, but the selectivity to the desired product was limited. Phosphoric acid showed the highest selectivity, and an excess of formaldehyde or catalyst loading significantly increased the yield of the target product. Water presence also led to increased selectivity. Additionally, a detailed mechanism for the 3-carene condensation with formaldehyde was proposed and confirmed through kinetic modeling.
MOLECULAR CATALYSIS
(2024)
Article
Chemistry, Physical
Meng-Yu Rong, Jing Nie, Shen Li, Jun-An Ma
Summary: We synthesized a new class of chiral quaternary ammonium salts and used them as catalysts in phase-transfer catalytic asymmetric alkylation. By employing these catalysts, we obtained a series of chiral fluorinated aromatic alpha-amino acid derivatives with high yields and enantioselectivities.
MOLECULAR CATALYSIS
(2024)
Article
Chemistry, Physical
Zhaozhou Wei, Guangtao Wei, Huixian Che, Deyuan Xiong, Linye Zhang, Ruihua Xue, Yalin Tang, Xuanli Lu
Summary: This study demonstrates that small-sized graphite crystallite and highly defective carbon-based catalysts can increase the -SO3H density of the catalysts and modulate their surface electronic properties, leading to improved efficiency in the alpha-pinene hydration reaction. The reduction of graphite crystallite size is considered a critical step in enhancing the selectivity of alpha-terpineol.
MOLECULAR CATALYSIS
(2024)
Article
Chemistry, Physical
Kempanna S. Kanakikodi, Nagendra Kulal, K. S. Subramanya, M. S. Puneethkumar, Bhavana B. Kulkarni, Ganapati Shanbhag, Sanjeev P. Maradur
Summary: An effective and highly selective protocol for synthesizing asymmetric organic carbonates using dimethyl carbonate (DMC) as a reactant and solvent has been developed. The performance of CeO2 nanostructures with different morphologies in the carbonate interchange reaction (CIR) of alcohols was investigated, and the CeO2 nano-catalyst with rod morphology exhibited the highest oxygen vacancy and remarkable enhancement in conversion. The CeO2 characterization data revealed that the exposed active sites, defect density, coordination state of surface atoms, and reducibility of the catalytic materials are the contributing factors to its high catalytic activity. CeO2 can be easily recovered and reused for multiple cycles.
MOLECULAR CATALYSIS
(2024)
Article
Chemistry, Physical
Yanzhao Gao, Xianglei Meng, Shiqi Huang, Hui Wu, Liantao Jiang, Yu Zhou, Yuting Song, Yanyan Diao
Summary: Gamma alumina modified with alkaline earth metal shows improved catalytic performance for hydrogenation reactions. Pd catalysts supported by Al2O3 and Mg-modified Al2O3 were synthesized and their structure, composition, and surface acidity were investigated. The results showed that Pd/MgO-Al2O3-2 catalyst exhibited the best catalytic performance due to its metallic state palladium and weak acid sites.
MOLECULAR CATALYSIS
(2024)