First-principles study of structure sensitivity of chain growth and selectivity in Fischer–Tropsch synthesis using HCP cobalt catalysts

2017 ◽  
Vol 7 (14) ◽  
pp. 2967-2977 ◽  
Author(s):  
Hai-Yan Su ◽  
Yonghui Zhao ◽  
Jin-Xun Liu ◽  
Keju Sun ◽  
Wei-Xue Li
Keyword(s):  
First Principles ◽  
Tropsch Synthesis ◽  
Structure Sensitivity ◽  
Cobalt Catalysts ◽  
Chain Growth ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Co Insertion ◽  
Insertion Mechanism ◽  
Methane Selectivity

Co (0001) prefers the CO insertion mechanism with high methane selectivity, but Co (101̄1) prefers the carbide mechanism with high C2-hydrocarbon selectivity.

Computational exploration of Fe55@C240-catalyzed Fischer–Tropsch synthesis

2018 ◽  
Vol 20 (4) ◽  
pp. 2741-2753 ◽  
Author(s):  
Geraldine Cilpa-Karhu ◽  
Kari Laasonen
Keyword(s):  
Dft Calculations ◽  
Hydrocarbon Chain ◽  
Tropsch Synthesis ◽  
Chain Growth ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Co Insertion ◽  
Computational Exploration ◽  
Insertion Mechanism

DFT calculations showed possible hydrocarbon chain growth on Fe55@C240 preferentially via a CO insertion mechanism.

Modelling Laboratory Fischer-Tropsch Synthesis Using Cobalt Catalysts

2018 ◽  
Vol 16 (11) ◽  
Author(s):  
Luis A. Díaz-Trujillo ◽  
Gilberto Toledo-Chávez ◽  
Gladys Jiménez-García ◽  
Héctor Hernández-Escoto ◽  
Rafael Maya-Yescas
Keyword(s):  
Equilibrium Constants ◽  
Fixed Bed ◽  
Reaction Rates ◽  
Tropsch Synthesis ◽  
Cobalt Catalysts ◽  
Chain Growth ◽  
Single Event ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Heterogeneous Kinetics

AbstractThe main goal of this paper is to critically review current microkinetics available for Fischer-Tropsch synthesis (FTS) modelling, in order to propose the best way to follow this set of complex reactions; therefore a microkinetic model was developed for FTS, accomplishing surface chemistry, heterogeneous kinetics, and single-event previous development for Co-based catalysts. Model starts simulating CO activation on catalyst surface, and then formation of methane, ethane and subsequent chain growth. Reaction rates were derived following the formalism of Langmuir-Hinshelwood-Hougen-Watson (LHHW); surface steps were proposed in consequence of feasibility. Chain growth was modelled by single-event steps, taking into account geometrical conformation explicitly. Number of growth steps of 1-olefins was rectified as requiring one more active site than mechanisms proposed previously; it was found that formation of these olefins exhibits a fast drop in chain growth; this phenomenon is explained in terms of probable geometrical conformations that lead to the number of single events. Experimental results in literature about isothermal synthesis of hydrocarbons in the gasoline range were simulated in a fixed-bed laboratory reactor; thermodynamic consistency was derived from chemical equilibrium over all reactions occurring during FTS. Equilibrium constants were evaluated as function of Gibbs free energy, and partial pressures of reactants and products.

CO-insertion mechanism based kinetic model of the Fischer–Tropsch synthesis reaction over Re-promoted Co catalyst

2014 ◽  
Vol 228 ◽  
pp. 32-39 ◽  
Author(s):  
Branislav Todic ◽  
Wenping Ma ◽  
Gary Jacobs ◽  
Burtron H. Davis ◽  
Dragomir B. Bukur
Keyword(s):  
Kinetic Model ◽  
Tropsch Synthesis ◽  
Synthesis Reaction ◽  
Fischer Tropsch ◽  
Co Catalyst ◽  
Fischer Tropsch Synthesis ◽  
Co Insertion ◽  
Insertion Mechanism
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