Enhancement of cobalt catalyst stability in Fischer–Tropsch synthesis using graphene nanosheets as catalyst support

Karimi, Saeed; Tavasoli, Ahmad; Mortazavi, Yadollah; Karimi, Ali

doi:10.1016/j.cherd.2015.10.016

Cited by 34 publications

(22 citation statements)

References 38 publications

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“…It is also worth noting that only in the case of Red-Me-Co 20 AlSiBeta after 20 h of reaction we observed a decrease in the selectivity towards C 1 -C 4 from 12.4% to almost zero. Other authors observed a similar tendency during long-term synthesis as reported in [46,47]. Furthermore, after 19 h, the mesporous partially dealuminated catalyst exhibited the selectivity to CO 2 of 9%.…”

Section: Catalytic Activity In Fischer-tropsch Synthesissupporting

confidence: 77%

Cobalt Based Catalysts Supported on Two Kinds of Beta Zeolite for Application in Fischer-Tropsch Synthesis

et al. 2019

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Co-containing Beta zeolite catalysts prepared by a wet impregnation and two-step postsynthesis method were investigated. The activity of the catalysts was examined in Fischer-Tropsch synthesis (FTS), performed at 30 atm and 260 °C. The physicochemical properties of all systems were investigated by means of X-ray diffraction (XRD), in situ XRD, temperature programmed desorption of ammonia (NH3-TPD), X-ray Photoelectron Spectroscopy (XPS), temperature programmed reduction of hydrogen (TPR-H2), and transmission electron microscopy (TEM). Among the studied catalysts, the best results were obtained for the samples prepared by a two-step postsynthesis method, which achieved CO conversion of about 74%, and selectivity to liquid products of about 86%. The distribution of liquid products for Red-Me-Co20Beta was more diversified than for Red-Mi-Co20Beta. It was observed that significant influence of the zeolite dealumination of mesoporous zeolite on the catalytic performance in FTS. In contrast, for microporous catalysts, the dealumination did not play such a significant role and the relatively high activity is observed for both not dealuminated and dealuminated catalysts. The main liquid products of FTS on both mesoporous and microporous catalysts were C10-C14 isoalkanes and n-alkanes. The iso-/n-alkanes ratio for dealuminated zeolite catalysts was three times higher than that for not dealuminated ones, and was related to the presence of different kind of acidic sites in both zeolite catalysts.

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Section: Catalytic Activity In Fischer-tropsch Synthesissupporting

confidence: 77%

Cobalt Based Catalysts Supported on Two Kinds of Beta Zeolite for Application in Fischer-Tropsch Synthesis

et al. 2019

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“…Due to the functionalization of GNS support, dispersion of NiMo particles on its surface is improved, and therefore these particles can substantially interact with the inner walls of the support. 7,14,22,24,[30][31] Furthermore, Figure 4A illustrates that NiMo nanoparticles of NMFG catalyst with small size of about 3.7 nm have a narrow and uniform distribution compared with NMAS catalyst. Higher dispersion of the NiMo nanoparticles on NMFG catalyst is compatible with the NH 3 -TPD results.…”

Section: Catalyst Characterizationmentioning

confidence: 98%

“…11 In recent years, GNS-supported HDC catalysts have attracted the attention of many researchers because of their specific textural properties and tunable chemical nature. [12][13][14] GNS can be prepared from different precursors such as wastes that should be subjected to additional treatments for enhancing their acidity by generating carboxylic groups on their surfaces. 10 These materials are good candidates for being used as a support because of their large specific areas, tunable surface groups, chemical stability, and easy metal recovery.…”

Section: Introductionmentioning

confidence: 99%

Graphene supported NiMo catalyst: A promising novel hydrocracking catalyst

Karimi¹,

Sadighi²

2020

Int J of Chemical Kinetics

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The graphene nanosheet (GNS) is used as a catalyst support for various catalytic reactions. A comprehensive study of functionalized GNS (FGNS)-supported catalyst for the purpose of hydrocracking (HDC) process provides a guide to exploring the potential applications and discovering their superior properties. In this research, to study the effect of the support on the conversion and selectivity of n-hexadecane HDC process, experiments are carried out over a synthesized NiMo/FGNS (NMFG) and a commercial NiMo/Al 2 O 3 -SiO 2 (NMAS) catalysts in a fixed-bed reactor. The functional groups on the NMFG surface anchor and disperse active metals on the catalyst surface, and they enhance the HDC conversion and stability of NMFG catalyst. Moreover, results prove that, in comparison with the commercial catalyst, NMFG increases the HDC conversion of n-hexadecane about 48%, and decreases the coke deposition on its surface.

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“…It is well-known that activity and selectivity in FTS are influenced by the properties of the support such as pore size distribution, specific surface area, and pore volume. 16 Moreover, compared with conventional oxide supports, these materials can enhance the reducibility of cobalt oxide. Carbon materials such as graphene, carbon nanofibers (CNFs), carbon nanotubes (CNTs), carbon spheres, and mesoporous carbons have attracted considerable attention as support materials for cobalt catalyst in recent years.…”

Section: Introductionmentioning

confidence: 99%

DFT Study on the Interaction of Subnanometer Cobalt Clusters with Pristine/Defective Graphene

Shahzad

Ren

Kim

2019

Bulletin Korean Chem Soc

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The cobalt nanoparticles deposited on graphene are new interesting catalytic systems for Fischer-Tropsch synthesis (FTS) to obtain clean fuel hydrocarbons. Especially, graphene doped with Co nanoparticles could be a nice alternative material for catalysis in CO + H 2 reaction. On the basis of first-principles calculation, we have analyzed the binding of Co n clusters (n = 1~7) with pristine (PGr) and defective graphene (DGr). Our analysis shows that the electronic structure of the graphene-supported Co subnanoclusters plays a significant role in the catalytic activity owing to metal-support interactions, and the interaction between the Co n clusters and the graphene is local. Our results also show that the bigger the size of Co n clusters is, the smaller the interaction between the cluster and the support is, and the lower its structural distortion is. In addition, the nucleation of Co n clusters on PGr is thermodynamically favorable, but the opposite trend is obtained for DGr. Both the pristine and defective surfaces facilitate agglomeration of Co 6 cluster, implying that the graphene support remarkably promotes and even prevents the sintering process of the small Co clusters. The Bader charge analysis shows that both the cobalt and graphene support are responsible for the charge densities of Co clusters.

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Enhancement of cobalt catalyst stability in Fischer–Tropsch synthesis using graphene nanosheets as catalyst support

Cited by 34 publications

References 38 publications

Cobalt Based Catalysts Supported on Two Kinds of Beta Zeolite for Application in Fischer-Tropsch Synthesis

Cobalt Based Catalysts Supported on Two Kinds of Beta Zeolite for Application in Fischer-Tropsch Synthesis

Graphene supported NiMo catalyst: A promising novel hydrocracking catalyst

DFT Study on the Interaction of Subnanometer Cobalt Clusters with Pristine/Defective Graphene

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