Thermal stability and hcp–fcc allotropic transformation in supported Co metal catalysts probed near operando by ferromagnetic NMR

2015 ◽  
Vol 17 (22) ◽  
pp. 14598-14604 ◽  
Author(s):  
Andrey S. Andreev ◽  
Jean-Baptiste d'Espinose de Lacaillerie ◽  
Olga B. Lapina ◽  
Alexander Gerashenko
Keyword(s):  
Thermal Stability ◽  
Metallic Phase ◽  
Metal Catalysts ◽  
Allotropic Transformation ◽  
Fischer Tropsch

Ferromagnetic NMR reveals which cobalt metallic phase is actually at work in Fischer–Tropsch catalysts and what is its state of dispersion under operando conditions.

Ru-doped transition metal catalysts for liquid-phase Fischer–Tropsch synthesis

2020 ◽  
Vol 130 (2) ◽  
pp. 813-823
Author(s):  
Mariia E. Markova ◽  
Alexandra V. Gavrilenko ◽  
Antonna A. Stepacheva ◽  
Valentina G. Matveeva ◽  
Mikhail G. Sulman ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Transition Metal ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Tropsch Synthesis ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis

Unstable Thermal Modes in Fischer-Tropsch Reactors With Fixed Pelletized Catalytic Bed

2010 ◽  
Author(s):  
I. V. Derevich ◽  
V. S. Ermolaev ◽  
V. Z. Mordkovich
Keyword(s):  
Thermal Stability ◽  
Heat Release ◽  
Synthesis Gas ◽  
Internal Heat ◽  
Diffusion Resistance ◽  
Oscillation Regime ◽  
Fischer Tropsch ◽  
Gas Concentration ◽  
Gas Consumption ◽  
Small Disturbances

Investigation of oscillation of temperature and synthesis gas concentration inside spherical catalytic particle it is executed. Approximate distributions of temperature and concentrations in a particle with internal heat release and synthesis gas consumption are obtained. Stationary distributions of thermal and gaseous parameters are found. In the frame of small disturbances of temperature and concentrations thermal stability is investigated. It is revealed, that diffusion resistance synthesis gas inside a porous particle can lead to occurrence oscillation regime.

scholarly journals Effect of Aromatic Concentration of a Fischer-Tropsch Fuel on Thermal Stability

2012 ◽  
Author(s):  
Jennifer Lindsey Suder Klettlinger
Keyword(s):  
Thermal Stability ◽  
Thermal Oxidation ◽  
Break Point ◽  
Jet Fuel ◽  
Fuel Composition ◽  
Fischer Tropsch ◽  
Commercial Grade ◽  
Testing Method ◽  
Aromatic Content ◽  
Thermal Stability Of

Fischer-Tropsch (F-T) jet fuel composition differs from petroleum-based, conventional commercial jet fuel because of differences in feedstock and production methodology. Fischer-Tropsch fuel typically has a lower aromatic and sulfur content and consists primarily of iso and normal parafins. The ASTM D3241 specification for Jet Fuel Thermal Oxidation Test (JFTOT) break point testing method was used to test the breakpoint of a baseline commercial grade F-T jet fuel, and various blends of this F-T fuel with an aromatic solution. The goal of this research is to determine the effect of aromatic content on the thermal stability of Fischer-Tropsch fuel. The testing completed in this report was supported by the NASA Fundamental Aeronautics Subsonics Fixed Wing Project.

scholarly journals Removal of sodium compounds from Co/SBA-15 catalysts for Fischer-Tropsch Synthesis

2020 ◽  
Vol 42 ◽  
pp. e45899
Author(s):  
Lidiane Sabino da Silva ◽  
Gabriela Gonzaga Cher ◽  
Maria Auxiliadora Scaramelo Baldanza ◽  
Victor Luis dos Santos Teixeira da Silva ◽  
Pedro Augusto Arroyo
Keyword(s):  
Heat Treatment ◽  
Metal Nanoparticles ◽  
Sodium Nitrate ◽  
Metallic Phase ◽  
Complexing Agent ◽  
Product Selectivity ◽  
Fischer Tropsch ◽  
Sodium Removal ◽  
Ft Synthesis ◽  
Almost All

 In the present work, the synthesis of Co/SBA-15 catalysts intended for Fischer-Tropsch (FT) synthesis was performed. During the synthesis of catalysts there was contamination of samples with sodium nitrate due to the nature of the reducing agent used for the synthesis of metallic phase. This kind of impurity is not advantageous for the FT reaction. Attempts at removal of sodium compounds were carried out by means of simple leaching treatments, using ethanol and acid ethylenediaminetetraacetic (EDTA) as solvent and complexing agent, respectively, followed by heat treatment at temperatures of 150 or 300°C. It was possible to conclude that the treatment using EDTA was more effective in removing almost all the alkaline phase of samples, despite the occurrence of oxidation, agglomeration, and removal of the metal nanoparticles in this process. In addition, there were no significant differences in the product selectivity of FT synthesis of the catalysts after sodium removal, although the nanoparticles were larger than 10 nm.

Operando X-ray absorption spectroscopy study of the Fischer–Tropsch reaction with a Co catalyst

2019 ◽  
Vol 26 (1) ◽  
pp. 137-144 ◽  
Author(s):  
Chandrani Nayak ◽  
Preeti Jain ◽  
C. P. Vinod ◽  
S. N. Jha ◽  
D. Bhattacharyya
Keyword(s):  
Absorption Spectroscopy ◽  
Catalytic Reaction ◽  
Structural Changes ◽  
Ambient Pressure ◽  
Metallic Phase ◽  
Fischer Tropsch ◽  
Co Catalyst ◽  
X Ray ◽  
Different Temperatures ◽  
X Ray Absorption

This article describes the setting up of a facility on the energy-scanning EXAFS beamline (BL-09) at RRCAT, Indore, India, for operando studies of structure–activity correlation during a catalytic reaction. The setup was tested by operando X-ray absorption spectroscopy (XAS) studies performed on a Co-based catalyst during the Fischer–Tropsch reaction to obtain information regarding structural changes in the catalyst during the reaction. Simultaneous gas chromatography (GC) measurements during the reaction facilitate monitoring of the product gases, which in turn gives information regarding the activity of the catalyst. The combination of XAS and GC techniques was used to correlate the structural changes with the activity of the catalyst at different reaction temperatures. The oxide catalyst was reduced to the metallic phase by heating at 400°C for 5 h under H2 at ambient pressure and subsequently the catalytic reaction was studied at four different temperatures of 240, 260, 280 and 320°C. The catalyst was studied for 10 h at 320°C and an attempt has been made to understand the process of its deactivation from the XANES and EXAFS results.

CO2 methanation over metal catalysts supported on ZrO2: Effect of the nature of the metallic phase on catalytic performance

2021 ◽  
pp. 116604
Author(s):  
Lizandra M.N.C. Alves ◽  
Mayra P. Almeida ◽  
Martin Ayala ◽  
Caleb D. Watson ◽  
Gary Jacobs ◽  
...  
Keyword(s):  
Catalytic Performance ◽  
Metallic Phase ◽  
Metal Catalysts ◽  
Co2 Methanation
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