An unconventional DCOx favored Co/N-C catalyst for efficient conversion of fatty acids and esters to liquid alkanes

Li, Jiang; Liu, Jiaxing; Zhang, Junjie; Wan, Tong; Huang, Lei; Wang, Xintian; Pan, Runze; An, Zhidong; Vlachos, Dionisios G.

doi:10.1016/j.apcata.2019.117385

Cited by 9 publications

(10 citation statements)

References 53 publications

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“…However, the “ n -alkanes with even carbon numbers/ n -alkanes with odd carbon numbers” ratio is higher in the case of cobalt–alumina catalysts with respect to the nickel–alumina ones . This is a clear evidence that cobalt catalysts favor more the contribution of deH 2 O pathway with respect to nickel ones, in agreement with the literature. ,,,, …”

Section: Resultssupporting

confidence: 88%

“…5 This is a clear evidence that cobalt catalysts favor more the contribution of deH 2 O pathway with respect to nickel ones, in agreement with the literature. 15,16,31,43,44 Concerning the green diesel production from SO, the catalytic performance follows the order 55CoAl 500 > 55CoAl 400 > 55CoAl 600 . In order to explain these results, we consider that the most active sites for the slow steps of SDO are situated on the surface of Co 0 and the interfaces of Co 0 /CoO where sites with moderate acidity are also developed (NH 3 -TPD results).…”

Section: Methodsmentioning

confidence: 99%

“…It is well-known that metallic cobalt accelerates hydrogenation/hydrogenolysis reactions, , being very important in the SDO of triglycerides process. However, although there are strong evidence for the quite good catalytic behavior of cobalt catalysts supported on various carriers for the aforementioned process, studies dealing with these catalysts are very few compared to those concerning the nickel ones. − Moreover, in most of the studies, the cobalt catalysts reported contain relatively small amounts of cobalt, and they have been prepared by some kind of impregnation. Finally, the catalytic tests were carried out in the presence of a solvent, using fresh plant oils and mainly model molecules as reactants (e.g., stearic, oleic, or palmitic acid).…”

Section: Introductionmentioning

confidence: 99%

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Cobalt–Alumina Coprecipitated Catalysts for Green Diesel Production

Nikolopoulos

Kogkos

Andriopoulou

et al. 2021

Ind. Eng. Chem. Res.

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Cobalt–alumina catalysts with high Co loading (35–70 wt %) were synthesized by coprecipitation. The influence of activation (reduction) temperature and the Co loading on their efficiency for green diesel production via selective deoxygenation (SDO) of solvent-free sunflower oil (SO) and waste cooking oil (WCO) has been investigated. The change of reduction temperature and the cobalt content caused remarkable changes in the physicochemical properties and catalytic behavior of the catalysts. A catalyst containing 55 wt % Co, activated at 500 °C, proved the most efficient. Its high efficiency has been attributed to its high metallic cobalt surface, the synergy between Co0/CoO phases, and its relatively enhanced moderate and strong acidity. The catalysts studied exhibited relatively lower performance in the SDO of WCO than that in the SDO of SO. This has been attributed to their deactivation caused by extended coking and concomitant pore blockage.

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Section: Resultssupporting

confidence: 88%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Cobalt–Alumina Coprecipitated Catalysts for Green Diesel Production

Nikolopoulos

Kogkos

Andriopoulou

et al. 2021

Ind. Eng. Chem. Res.

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“…After achieving steady state during CO oxidation at 273 K, the reactant stream was abruptly switched to one that contains 13 CO instead of 12 CO using the scheme shown in Figure S1. More experimental details can be found in Section 2, and an example switch between 12 CO/Ar and 13 CO/He during steady-state CO oxidation is shown in Figure 6a. In brief, the integration of the areas under the product 12 CO 2 or 13 CO 2 subtracted from the tracer Ar signal gives the average residence time of surface intermediates leading to product (τ).…”

Section: Steady-state Isotopic Transient Kinetic Analysismentioning

confidence: 99%

Mechanistic Insights on the Low-Temperature Oxidation of CO Catalyzed by Isolated Co Ions in N-Doped Carbon

et al. 2022

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Isolated cobalt ions on nitrogen-doped carbon (Co−N−C) catalyze CO oxidation at temperatures as low as 196 K, but the active site and mechanism for this reaction remain elusive. In this work, steady-state CO oxidation around 273 K over Co−N−C revealed nearly first-order behavior in both CO and O 2 as well as a negative apparent activation energy. Isotopic transient analysis of the reaction confirmed a rapid turnover frequency and low surface coverage of adsorbed intermediates leading to CO 2 (<10% of the Co). Results from kinetics experiments combined with quantum chemical calculations and molecular dynamics simulations are consistent with a reaction path involving weak adsorption of CO onto Co ions followed by a low barrier for the CO-assisted activation of weakly adsorbed O 2 . This proposed mechanism for dioxygen activation does not involve a redox cycle with the transition-metal ion and may be important in other low-temperature catalytic reactions involving O 2 .

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“…It was shown that transition metal catalysts result in HDO or DO processes [14][15][16][17][18][19][20][21][22]. In some studies, DCN was mentioned as an unconventional pathway for fatty acid conversion to hydrocarbons over transition metal catalysts [23,24]. Noble metals, in contrast, catalyze DCN/DCX or hydrogenation reactions [13,[25][26][27][28].…”

Section: Introductionmentioning

confidence: 99%

Alkane Production from Unsaturated Fatty Acids over Transition Metal‐Doped Pd Catalysts

et al. 2021

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Alkane production from fatty acids and their derivatives can be considered one of the most-studied processes. Such reactions as hydrogenation, hydrodeoxygenation, decarboxylation, and decarbonylation are the main routes for this process. The reaction pathway depends on the nature of the catalyst, the presence of hydrogen, and the hydrogen source. In this work, a mixture of unsaturated fatty acids (oleic and linoleic acids) was converted to alkanes (mainly heptadecane) in a hydrogen-free atmosphere by using 2-propanol as hydrogen donor. Transition metal doped Pd catalysts embedded on a porous organic support (hypercrosslinked polystyrene) were used as catalysts. A Pd-Cu catalyst showed the highest effectiveness, allowing up to 99.9 mol % selectivity to heptadecane to be obtained. The process proceeds through fatty acid esterification, further hydrogenation of double bonds, and decarboxylation to form n-heptadecane as main product.

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An unconventional DCOx favored Co/N-C catalyst for efficient conversion of fatty acids and esters to liquid alkanes

Cited by 9 publications

References 53 publications

Cobalt–Alumina Coprecipitated Catalysts for Green Diesel Production

Cobalt–Alumina Coprecipitated Catalysts for Green Diesel Production

Mechanistic Insights on the Low-Temperature Oxidation of CO Catalyzed by Isolated Co Ions in N-Doped Carbon

Alkane Production from Unsaturated Fatty Acids over Transition Metal‐Doped Pd Catalysts

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