Effect of annealing on rhenium catalyst activity in ammonia synthesis

1976 ◽  
Vol 11 (6) ◽  
pp. 707-707
Author(s):  
V. K. Yatsimirskii ◽  
N. I. Girenkova ◽  
A. F. Khrienko
Keyword(s):  
Ammonia Synthesis ◽  
Catalyst Activity

scholarly journals Poisoning of Ammonia Synthesis Catalyst Considering Off-Design Feed Compositions

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1225
Author(s):  
Alireza Attari Moghaddam ◽  
Ulrike Krewer
Keyword(s):  
Ammonia Synthesis ◽  
Model Simulation ◽  
Catalyst Activity ◽  
Water Electrolysis ◽  
Gas Composition ◽  
Catalyst Poisoning ◽  
Bosch Process ◽  
Microkinetic Model ◽  
Water Contents ◽  
Hydrogen Stream

Activity of ammonia synthesis catalyst in the Haber-Bosch process is studied for the case of feeding the process with intermittent and impurity containing hydrogen stream from water electrolysis. Hydrogen deficiency due to low availability of renewable energy is offset by increased flow rate of nitrogen, argon, or ammonia, leading to off-design operation of the Haber-Bosch process. Catalyst poisoning by ppm levels of water and oxygen is considered as the main deactivation mechanism and is evaluated with a microkinetic model. Simulation results show that catalyst activity changes considerably with feed gas composition, even at exceptionally low water contents below 10ppm. A decreased hydrogen content always leads to lower poisoning of the catalyst. It is shown that ammonia offers less flexibility to the operation of Haber-Bosch process under fluctuating hydrogen production compared to nitrogen and argon. Transient and significant changes of catalyst activity are expected in electrolysis coupled Haber-Bosch process.

scholarly journals Carrying Agent Influence on the Ruthenium Catalyst Activity of the Ammonia Synthesis

2015 ◽  
Vol 113 ◽  
pp. 84-90 ◽  
Author(s):  
N.S. Smirnova ◽  
V.A. Borisov ◽  
K.N. Iost ◽  
V.L. Temerev ◽  
Ju.V. Surovikin ◽  
...  
Keyword(s):  
Ammonia Synthesis ◽  
Catalyst Activity ◽  
Ruthenium Catalyst

Effects of Support and Promoter on Ru Catalyst Activity in Microwave-assisted Ammonia Synthesis

2021 ◽  
pp. 130546
Author(s):  
Yuxin Wang ◽  
Christina Wildfire ◽  
Tuhin S. Khan ◽  
Dushyant Shekhawat ◽  
Jianli Hu ◽  
...  
Keyword(s):  
Ammonia Synthesis ◽  
Catalyst Activity ◽  
Ru Catalyst ◽  
Microwave Assisted

Investigation of Carbon Nanofiber Supported Iron Catalyst Preparation by Deposition Precipitation

2014 ◽  
Vol 1043 ◽  
pp. 71-75 ◽  
Author(s):  
Nguyen van Thien Duc ◽  
Suriati Sufian ◽  
Nurlidia Mansor ◽  
Noorhana Yahya
Keyword(s):  
Particle Size ◽  
Carbon Nanofiber ◽  
Ammonia Synthesis ◽  
Iron Catalyst ◽  
Catalyst Activity ◽  
Support Surface ◽  
Adsorption Sites ◽  
Transmission Electron ◽  
Technological Challenge ◽  
Supported Iron

An ammonia synthesis using magnetic field to replace Haber-Bosch’s ammonia production is great technological challenge in novel magnetized catalysts area. The carbon nanofiber supported iron catalyst was prepared by modifying carbon nanofiber support surface and later using urea to precipitate iron nitrate by deposition precipitation. It was found that the particle size was in a range of 5-50nm and well dispersion of iron was shown by transmission electron microscopy. This was strongly influenced by alteration of carbon nanofiber surface from hydrophobic to hydrophilic and with high adsorption sites as oxygen functional groups and defects. The lower iron loading between 5 and 40%wt, the lower iron accumulation and the narrower the particle size distribution of 10-20nm. The result suggests that the iron particles are in a good size range for iron catalyst activity for ammonia synthesis as reported by Morawski et.al and Figurski et.al authors.

Electron Donation by Low-Crystalline Ba-La-Ce Oxygen-Deficient Composite Oxide Accumulating on Ru Nanoparticles for Ammonia Synthesis under Mild Conditions

2019 ◽  
Author(s):  
Katsutoshi Sato ◽  
Shin-ichiro Miyahara ◽  
Yuta Ogura ◽  
Kotoko Tsujimaru ◽  
Yuichiro Wada ◽  
...  
Keyword(s):  
Ammonia Synthesis ◽  
Bond Cleavage ◽  
Synthesis Process ◽  
Strong Electron ◽  
Mild Conditions ◽  
Ru Nanoparticles ◽  
Rate Determining Step ◽  
Highly Active ◽  
Composite Oxides ◽  
Low Crystalline

<p>To mitigate global problems related to energy and global warming, it is helpful to develop an ammonia synthesis process using catalysts that are highly active under mild conditions. Here we show that the ammonia synthesis activity of Ru/Ba/LaCeO<i><sub>x</sub></i> pre-reduced at 700 °C is the highest reported among oxide-supported Ru catalysts. Our results indicate that low crystalline oxygen-deficient composite oxides, which include Ba<sup>2+</sup>, Ce<sup>3+</sup> and La<sup>3+</sup>, with strong electron-donating ability, accumulate on Ru particles and thus promote N≡N bond cleavage, which is the rate determining step for ammonia synthesis.</p>

Electron Donation by Low-Crystalline Ba-La-Ce Oxygen-Deficient Composite Oxide Accumulating on Ru Nanoparticles for Ammonia Synthesis under Mild Conditions

2019 ◽  
Author(s):  
Katsutoshi Sato ◽  
Shin-ichiro Miyahara ◽  
Yuta Ogura ◽  
Kotoko Tsujimaru ◽  
Yuichiro Wada ◽  
...  
Keyword(s):  
Ammonia Synthesis ◽  
Bond Cleavage ◽  
Synthesis Process ◽  
Strong Electron ◽  
Mild Conditions ◽  
Ru Nanoparticles ◽  
Rate Determining Step ◽  
Highly Active ◽  
Composite Oxides ◽  
Low Crystalline

<p>To mitigate global problems related to energy and global warming, it is helpful to develop an ammonia synthesis process using catalysts that are highly active under mild conditions. Here we show that the ammonia synthesis activity of Ru/Ba/LaCeO<i><sub>x</sub></i> pre-reduced at 700 °C is the highest reported among oxide-supported Ru catalysts. Our results indicate that low crystalline oxygen-deficient composite oxides, which include Ba<sup>2+</sup>, Ce<sup>3+</sup> and La<sup>3+</sup>, with strong electron-donating ability, accumulate on Ru particles and thus promote N≡N bond cleavage, which is the rate determining step for ammonia synthesis.</p>

Preparation and Evaluation of Skeletal Cobalt-Molybdenum Hydrodesulfurization Catalysts

1995 ◽  
Vol 60 (4) ◽  
pp. 568-575
Author(s):  
Karel Sporka ◽  
Jiří Hanika ◽  
Vladimír Jůn
Keyword(s):  
Aqueous Solutions ◽  
Active Component ◽  
Catalyst Activity ◽  
Gas Oil ◽  
Gamma Alumina ◽  
Molybdenum Sulfides ◽  
Hydrodesulfurization Catalysts ◽  
Hds Catalysts ◽  
Kinetics Of ◽  
Preparation And Evaluation

Preparation of skeletal Co-Mo catalysts by controlled impregnation of aluminosilicate skeletons containing deposited gamma-alumina with aqueous solutions of active component precursors has been investigated. The activity of the laboratory catalysts in gas oil hydrodesulfurization has been determined. Kinetics of impregnation of skeletal supports, the effect of their type, and the dependence of catalyst activity on the content of cobalt and molybdenum sulfides are reported. HDS skeletal catalysts prepared were compared with the extruded types. It was found that skeletal HDS catalysts show the higher activity (related to the content of alumina and Co-Mo sulfides) than the extruded ones due to the less significant effect of internal diffusion. However, if the activity is related to the same volume of catalyst bed, the activity of skeletal catalysts is only one fourth of that of the extruded types.

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