Fischer–Tropsch synthesis on Co/AlSBA-15: effects of hydrophilicity of supports on cobalt dispersion and product distributions

2015 ◽  
Vol 5 (7) ◽  
pp. 3525-3535 ◽  
Author(s):  
Jae Min Cho ◽  
Chang Il Ahn ◽  
Changhyun Pang ◽  
Jong Wook Bae
Keyword(s):  
Outer Surface ◽  
Acid Sites ◽  
Tropsch Synthesis ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Support Interaction ◽  
Product Distributions ◽  
Metal Support Interaction ◽  
Metal Support

The increased C2–C4selectivity on the Co/AlSBA-15 was mainly attributed to the formation of small cobalt particles with a stronger metal–support interaction on the outer surface acid sites of the AlSBA-15 due to a higher hydrophilicity of the Al-incorporated SBA-15.

Isomorphic titanium-substituted mesoporous SBA-16 as support for cobalt Fischer–Tropsch synthesis catalysts: Balance between dispersion and reduction

2021 ◽  
Author(s):  
Liang Wei ◽  
Jian Chen ◽  
Shuai Lyu ◽  
Chengchao Liu ◽  
Yanxi Zhao ◽  
...  
Keyword(s):  
Catalytic Performance ◽  
Tropsch Synthesis ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Support Interaction ◽  
Delicate Balance ◽  
Metal Support Interaction ◽  
Metal Support ◽  
Synthesis Catalysts

The delicate balance between dispersion and reduction of the Co-based Fischer–Tropsch synthesis catalyst is the golden key to enhancing catalytic performance, which highly depends on an optimized metal–support interaction. In...

Ruthenium nanoclusters dispersed on titania nanorods and nanoparticles as high-performance catalysts for aqueous-phase Fischer–Tropsch synthesis

2016 ◽  
Vol 6 (23) ◽  
pp. 8355-8363 ◽  
Author(s):  
Jing-Wen Yu ◽  
Wei-Zhen Li ◽  
Tao Zhang ◽  
Ding Ma ◽  
Ya-Wen Zhang
Keyword(s):  
Aqueous Phase ◽  
High Performance ◽  
Tropsch Synthesis ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Support Interaction ◽  
Metal Support Interaction ◽  
Metal Support

The high AFTS activity and C5+ selectivity of the serial Ru/TiO2 nanocatalysts were favoured by the increasing metallic Ru sites due to H2 reduction pretreatment and weak metal–support interaction.

Fischer-Tropsch synthesis: Variation of Co/ ${{\gamma}}$ γ -Al2O3 catalyst performance due to changing dispersion, reducibility, acidity and strong metal-support interaction by Ru, Zr and Ce promoters

2017 ◽  
Vol 16 (2) ◽  
Author(s):  
Moradian Amin ◽  
Bahadoran Farzad ◽  
Shirazi Laleh ◽  
Zamani Yahya
Keyword(s):  
Catalyst Activity ◽  
Tropsch Synthesis ◽  
Fischer Tropsch ◽  
Reduction Behavior ◽  
Fischer Tropsch Synthesis ◽  
Support Interaction ◽  
Metal Support Interaction ◽  
Metal Support ◽  
Smsi Effect ◽  
Strong Metal Support Interaction

AbstractIn this study the effect of (0.1 %Ru, 0–10 % Zr) and (0.1 %Ru, 0–10 % Ce) promoters on dispersion, strong metal-support interaction and reduction behavior of cobalt-supported alumina catalyst in the Fischer-Tropsch synthesis was investigated. The synthesized catalysts were characterized by BET, XRD, ICP, TPR, XPS, and TEM techniques. The results show that addition of Ce to the catalyst leads to the shift of the TPR peaks to lower temperatures which expected that shows higher activity due to higher reducibility, but surprisingly due to SMSI effect results in the lower catalyst activity compared with the unpromoted catalyst. Also, there was a synergistic effect between Ce and Ru in the reduction behavior of Ru-Ce promoted catalyst. The other notable finding of this study was the improvement in the catalyst reducibility in the presence of Zr compared with the unpromoted one that equivalently means the higher catalyst activity. Comparison of the Zr-promoted with the Ce-promoted catalysts show that the former have higher catalyst activity than the latter due to higher acidity and SMSI effect in the presence of the Zr promoter. The C5selectivity of the 0.1Ru10Zr/15Co and 3Ce/15Co catalysts at low pressure have shown more than 50 % improvement compared to the unpromoted one. Based on the activity at atmospheric pressure; the unpromoted, 0.1Ru/15Co, 0.1Ru3Ce/15Co and 0.1Ru10Zr/15Co catalysts were selected for high pressure condition tests, in which the 0.1Ru10Zr/15Co catalyst shows the highest catalyst activity and heavier hydrocarbon selectivity.

Ru/TiO2 Catalysts with Size-Dependent Metal/Support Interaction for Tunable Reactivity in Fischer–Tropsch Synthesis

ACS Catalysis ◽  
2020 ◽  
Vol 10 (21) ◽  
pp. 12967-12975
Author(s):  
Yaru Zhang ◽  
Xiong Su ◽  
Lin Li ◽  
Haifeng Qi ◽  
Chongya Yang ◽  
...  
Keyword(s):  
Tropsch Synthesis ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Size Dependent ◽  
Support Interaction ◽  
Metal Support Interaction ◽  
Metal Support

scholarly journals Significance of C3 Olefin to Paraffin Ratio in Cobalt Fischer–Tropsch Synthesis

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 967
Author(s):  
Erling Rytter ◽  
Jia Yang ◽  
Øyvind Borg ◽  
Anders Holmen
Keyword(s):  
Residence Time ◽  
Tropsch Synthesis ◽  
Cobalt Catalysts ◽  
Feed Ratio ◽  
Water Addition ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Metal Support Interaction ◽  
Metal Support ◽  
Added Water

The ratio between propene and propane (C3 o/p) during Fischer–Tropsch synthesis (FTS) has been analyzed based on both literature reports and experiments for five catalysts. The latter comprise four cobalt catalysts on γ-alumina with variations in pore sizes, and one catalyst on α-alumina. Overall variations include H2/CO feed ratio, residence time, water addition, transients between test conditions, CO conversion, cobalt particle size, promoter (Re), and support material. It was possible to rationalize all data based on secondary hydrogenation of olefins. In fact, it was deduced that olefins are dominating termination products in FTS, estimated to ca. 90% for C3, but that some paraffins most likely are also produced directly. Increased residence time and high H2/CO feed ratio favors olefin hydrogenation, while added water presumably displaces hydrogen on cobalt giving enhanced C3 o/p. High cobalt dispersion favors hydrogenation, as also promoted by Re. Effect of intraparticle diffusion is seen in transient periods; for example, as water is added or depleted. There is frequently positive correlation between C3 o/p and selectivity to longer chains; the latter expressed as C5+ selectivity, as both are sensitive to hydrogen activity. Some modifications, however, are needed due to the accepted volcano plot for C5+ selectivity with cobalt crystallite size. Titania as support shows unexpectedly low C3 o/p; probably due to SMSI (strong-metal-support-interaction).

Product Distributions of Fischer-Tropsch Synthesis over Core-Shell Catalysts: The Effects of Diverse Shell Thickness

2018 ◽  
Vol 3 (44) ◽  
pp. 12415-12423 ◽  
Author(s):  
Zhipeng Tian ◽  
Chenguang Wang ◽  
Zhan Si ◽  
Yachen Wang ◽  
Lungang Chen ◽  
...  
Keyword(s):  
Shell Thickness ◽  
Tropsch Synthesis ◽  
Core Shell ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Product Distributions

Size dependent stability of cobalt nanoparticles on silica under high conversion Fischer–Tropsch environment

2017 ◽  
Vol 197 ◽  
pp. 243-268 ◽  
Author(s):  
Moritz Wolf ◽  
Hendrik Kotzé ◽  
Nico Fischer ◽  
Michael Claeys
Keyword(s):  
Type Species ◽  
Tropsch Synthesis ◽  
High Conversion ◽  
Metallic Surface ◽  
Metallic State ◽  
Direct Oxidation ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Metal Support ◽  
Presence And Absence

Highly monodisperse cobalt crystallites, supported on Stöber silica spheres, as model catalysts for the Fischer–Tropsch synthesis were exposed to simulated high conversion environments in the presence and absence of CO utilising an in house developedin situmagnetometer. The catalyst comprising the smallest crystallites in the metallic state (average diameter of 3.2 nm) experienced pronounced oxidation whilst the ratio of H2O to H2was increased stepwise to simulate CO conversions from 26% up to complete conversion. Direct exposure of this freshly reduced catalyst to a high conversion Fischer–Tropsch environment resulted in almost spontaneous oxidation of 40% of the metallic cobalt. In contrast, a model catalyst with cobalt crystallites of 5.3 nm only oxidised to a small extent even when exposed to a simulated conversion of over 99%. The largest cobalt crystallites were rather stable and only experienced measurable oxidation when subjected to H2O in the absence of H2. This size dependency of the stability is in qualitative accordance with reported thermodynamic calculations. However, the cobalt crystallites showed an unexpected low susceptibility to oxidation,i.e.only relatively high ratios of H2O to H2partial pressure caused oxidation. Similar experiments in the presence of CO revealed the significance of the actual Fischer–Tropsch synthesis on the metallic surface as the dissociation of CO, an elementary step in the Fischer–Tropsch mechanism, was shown to be a prerequisite for oxidation. Direct oxidation of cobalt to CoO by H2O seems to be kinetically hindered. Thus, H2O may only be capable of indirect oxidation,i.e.high concentrations prevent the removal of adsorbed oxygen species on the cobalt surface leading to oxidation. However, a spontaneous direct oxidation of cobalt at the interface between the support and the crystallites by H2O forming presumably cobalt silicate type species was observed in the presence and absence of CO. The formation of these metal–support compounds is in accordance with conducted thermodynamic predictions. None of the extreme Fischer–Tropsch conditions initiated hydrothermal sintering. Seemingly, the formation of metal–support compounds stabilised the metallic crystallites and/or higher partial pressures of CO are required to increase the concentration of mobile, cobalt oxide-type species on the metallic surface.

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