Effect of TiO2 promotion on the structure and performance of silica-supported cobalt-based catalysts for Fischer–Tropsch synthesis

Wu, Huatao; Yang, Yong; Suo, Haiyun; Qing, Ming; Lü, Yan; Wu, Baoshan; Xu, Jian; Xiang, Huimin; Li, Yongwang

doi:10.1016/j.molcata.2014.03.004

Cited by 21 publications

(16 citation statements)

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“…They enhanced the formation of alkanes by adding the Pd as the promoter, which resulted in higher selectivity of heavy alkanes, methyl-branched paraffins as well as alcohols. Wu et al [79] concluded from their work that adding a small amount of TiO 2 could enhance the reducibility of a cobalt catalyst supported with silica gel by affecting the support-catalyst interaction and subsequently could result in higher FTS reaction activity. The dispersion of active metal was improved as well by the addition of TiO 2 .…”

Section: Overview Of Previous Work Regarding the Fischer-tropsch Synmentioning

confidence: 99%

A review of Fischer Tropsch synthesis process, mechanism, surface chemistry and catalyst formulation

Mahmoudi

Doustdar

et al. 2017

Biofuels Engineering

165

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For more than half a century, Fischer-Tropsch synthesis (FTS) of liquid hydrocarbons was a technology of great potential for the indirect liquefaction of solid or gaseous carbon-based energy sources (Coal-To-Liquid (CTL) and Gas-To-Liquid (GTL)) into liquid transportable fuels. In contrast with the past, nowadays transport fuels are mainly produced from crude oil and there is not considerable diversity in their variety. Due to some limitations in the first generation bio-fuels, the Second-Generation Biofuels (SGB)' technology was developed to perform the Biomass-To-Liquid (BTL) process. The BTL is a well-known multi-step process to convert the carbonaceous feedstock (biomass) into liquid fuels via FTS technology. This paper presents a brief history of FTS technology used to convert coal into liquid hydrocarbons; the significance of bioenergy and SGB are discussed as well. The paper covers the characteristics of biomass, which is used as feedstock in the BTL process. Different mechanisms in the FTS process to describe carbon monoxide hydrogenation as well as surface polymerization reaction are discussed widely in this paper. The discussed mechanisms consist of carbide, COinsertion and the hydroxycarbene mechanism. The surface chemistry of silica support is discussed. Silanol functional groups in silicon chemistry are explained extensively. The catalyst formulation in the Fischer Tropsch (F-T) process as well as F-T reaction engineering is discussed. In addition, the most common catalysts are introduced and the current reactor technologies in the F-T indirect liquefaction process are considered. process overview IntroductionThe over-reliance of the world's nations on conventional fossil fuels puts our planet in peril. The continuity of the current situation will result in the rise of a combined average temperature over global land and ocean surfaces by 5 ∘ C in 2100, bringing a rise in sea levels, food and water shortages and an increase in extreme weather events. The global warming, caused by humans, is one of the biggest threats to our future well-being [1]. In addition, oil reserves are limited and these reserves are decreasing dramatically. This reduction alongside the other relevant economic factors affects the world's oil prices. The need to run engines with the new generation of liquid fuels is inevitable. The investigations by the US Energy Information Administration (EIA) published in 2013 expressed a 56 percent increase in the world's energy consumption by the year 2040. Total world energy demand will have risen to 865 EJ (exajoule) by this year. The total world energy consumption was reported as 553 EJ in 2010. The outlook indicates that renewable energy is one of the fastest-growing energy sources in the world; where its usage increases 2.5 percent per year. Despite increasing success in the renewable energies, it is predicted that the fossil fuels will supply al-

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Section: Overview Of Previous Work Regarding the Fischer-tropsch Synmentioning

confidence: 99%

A review of Fischer Tropsch synthesis process, mechanism, surface chemistry and catalyst formulation

Mahmoudi

Doustdar

et al. 2017

Biofuels Engineering

165

View full text Add to dashboard Cite

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“…This result is in agreement with other reports, which have showed that silicon-containing supports loaded with tunable low amounts of titanium promote an increase in the dispersion of the respective studied active species. [16,28,65,66] The Co-catalysts supported on pure SiO 2 or TiO 2 (Fig. 6b) showed considerably different reduction profiles from the catalysts supported on silica-titania.…”

Section: Stco-op1mentioning

confidence: 93%

“…[1,[9][10][11][12][13][14] Cobalt oxides, Co 3 O 4 especially, present excellent activity in said reaction as a consequence of the capability of oxygen uptaking in their lattice structure; additionally, they readily undergo redox reactions in which pair Co 2+ ↔ Co 3+ deeply participates in the reaction through the adsorption of the CO and O 2 reactant molecules. Furthermore, several reports in the literature discuss the great importance of the Co 3+ cation in the process, since this species is the most active one for the CO adsorption and oxidation, whereas the Co 2+ species possess a lower activity [15,16]. The CO oxidation mechanism over Co 3 O 4 involves four fundamental steps, which are: (i) CO adsorption, (ii) reaction between the adsorbed CO and a lattice oxygen from Co 3 O 4 , forming an adsorbed CO 2 molecule, (iii) CO 2 desorption, (iv) adsorption of an oxygen molecule, restoring the oxidation state of the active site and lattice oxygen [17].…”

Section: Introductionmentioning

confidence: 99%

CO oxidation over Co-catalysts supported on silica-titania – The effects of the catalyst preparation method and the amount of incorporated Ti on the formation of more active Co3+ species

Lima

Castelblanco

Rodrigues

et al. 2018

Applied Catalysis A: General

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Herein, a sol-gel one-pot methodology to tune the activity of Co-catalysts supported on silica-titania to CO oxidation is described. SEM, TEM, EDS, XPS and H 2-TPR evidenced a higher Co dispersion from that method when compared to catalysts prepared by impregnation. Furthermore, the simultaneous addition of cobalt oxalate during the incorporation by sol-gel of a controlled low Ti amount into the silica (Si/Ti = 5.7) was determinant to improve the Co dispersion and to avoid the formation of Co-species with strong support interaction. Moreover, XPS analyses evidenced that the mentioned low Ti amount favoured a higher formation of superficial Co 3+ and lattice O 2− species, which promoted a higher CO oxidation specific activity and, more importantly, strongly decreasing the light-off temperature. On the other hand, Rietveld analyses, Raman spectroscopy, H 2-TPR and XPS data showed that the incorporation of higher amounts of Ti into the silica (Si/Ti = 0.2) led to the formation of cobalt titanate, decreasing the concentration of superficial Co 3+ and lattice O 2− species and, consequently, decreasing the specific activity toCO oxidation.

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“…In this context, in order to achieve a high dispersion of surface active cobalt species, in some cases metal-support interaction is to stabilize the catalyst. Therefore, different supports have been studied such as titanium or magnesium oxides, zeolites, mesoporous silica (MCM-41 and SBA-15) [106,108,109], and carbon nanostructures (CNFs, MWCNTs, and CSc) [105,110].…”

Section: Cobalt-based Catalystsmentioning

confidence: 99%

Synthesis of Supported Mesoporous Catalysts Using Supercritical CO₂

Aspromonte¹,

Piovano²,

Alonso³

et al. 2020

Advances in Microporous and Mesoporous Materials

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Metal and metal oxide nanoparticles have attracted increased attention due to their unusual physical and chemical properties. The nature, dispersion, and size of the nanoparticles are key factors in determining the activity and selectivity of the supported catalysts. Supercritical fluid deposition (SCFD) is a promising method to deposit metallic nanoparticles and films on inorganic porous supports. CO 2 is the most commonly used supercritical fluid (sc-CO 2) for material synthesis because it is nontoxic, nonreactive, nonflammable, and inexpensive. This work presents the synthesis of cobalt, nickel, and ruthenium nanoparticles on MCM-41, Al-MCM-41, MCM-48, and activated carbon supports in sc-CO 2. Batch and continuous deposition are studied, with two high-pressure reactor configurations: column or alternative (sandwich). To avoid the length of the bed being too long, the reagents were separated into smaller amounts and placed alternately, keeping the total mass of the precursor and support constant. The prepared samples were characterized by scanning electron (SEM/EDX) and transmission electron microscopy (TEM).

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Effect of TiO2 promotion on the structure and performance of silica-supported cobalt-based catalysts for Fischer–Tropsch synthesis

Cited by 21 publications

References 50 publications

A review of Fischer Tropsch synthesis process, mechanism, surface chemistry and catalyst formulation

A review of Fischer Tropsch synthesis process, mechanism, surface chemistry and catalyst formulation

CO oxidation over Co-catalysts supported on silica-titania – The effects of the catalyst preparation method and the amount of incorporated Ti on the formation of more active Co3+ species

Synthesis of Supported Mesoporous Catalysts Using Supercritical CO₂

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Effect of TiO2 promotion on the structure and performance of silica-supported cobalt-based catalysts for Fischer–Tropsch synthesis

Cited by 21 publications

References 50 publications

A review of Fischer Tropsch synthesis process, mechanism, surface chemistry and catalyst formulation

A review of Fischer Tropsch synthesis process, mechanism, surface chemistry and catalyst formulation

CO oxidation over Co-catalysts supported on silica-titania – The effects of the catalyst preparation method and the amount of incorporated Ti on the formation of more active Co3+ species

Synthesis of Supported Mesoporous Catalysts Using Supercritical CO2

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Synthesis of Supported Mesoporous Catalysts Using Supercritical CO₂