Ligand effects on the redox reactions in nickel- and copper-exchanged zeolites

Kasai, Paul H.; Bishop, R.J.; McLeod, Dayan Niles

doi:10.1021/j100492a006

Cited by 76 publications

(59 citation statements)

References 6 publications

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“…Microalgae oil mainly consists of neutral lipids such as mono-, di-, and triglyceride. The microalgae oil (provided by Verfahrenstechnik Schwedt GmbH) used here is composed of unsaturated C 18 fatty acids (88.4 wt %), saturated C 18 fatty acids (4.4 wt %), as well as some other C 14 , C 16 , C 20 , C 22 , and C 24 fatty acids (7.1 wt % in total). The mechanism for hydrodeoxygenation of microalgae oil [4a] has been proposed to proceed through an initial metal-catalyzed hydrogenation of the double bonds in the alkyl chain, followed by hydrogenolysis of the formed saturated triglyceride leading to fatty acid and propane production.…”

Section: Wwwchemeurjorgmentioning

confidence: 99%

Importance of Size and Distribution of Ni Nanoparticles for the Hydrodeoxygenation of Microalgae Oil

Song

Zhao

Lercher

2013

Chemistry A European J

140

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Improved synthetic approaches for preparing small-sized Ni nanoparticles (d=3 nm) supported on HBEA zeolite have been explored and compared with the traditional impregnation method. The formation of surface nickel silicate/aluminate involved in the two precipitation processes are inferred to lead to the stronger interaction between the metal and the support. The lower Brønsted acid concentrations of these two Ni/HBEA catalysts compared with the parent zeolite caused by the partial exchange of Brønsted acid sites by Ni(2+) cations do not influence the hydrodeoxygenation rates, but alter the product selectivity. Higher initial rates and higher stability have been achieved with these optimized catalysts for the hydrodeoxygenation of stearic acid and microalgae oil. Small metal particles facilitate high initial catalytic activity in the fresh sample and size uniformity ensures high catalyst stability.

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Section: Wwwchemeurjorgmentioning

confidence: 99%

Importance of Size and Distribution of Ni Nanoparticles for the Hydrodeoxygenation of Microalgae Oil

Song

Zhao

Lercher

2013

Chemistry A European J

140

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“…The previous works revealed that two acid sites generated for each Ni 2? on Ni-containing catalysts during the thermal processes above 300°C as the following equation [26,27]:…”

Section: Discussionmentioning

confidence: 99%

“…In addition, the strong acid sites can be partially substituted by the weak/medium acid sites generating from Ni cations [26,27]. In this work, Ni-doped zeolite catalysts are calcined at 550°C and activated at 450°C.…”

Section: Discussionmentioning

confidence: 99%

Trimerization of Butene over Ni-doped Zeolite Catalyst: Effect of Textural and Acidic Properties

et al. 2008

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The amount of acid sites on external surface and L/B ratio of the zeolite catalysts are close relative to the catalytic performance of the catalysts in butene trimerization. The doping of Ni into the zeolite modifies the textural and acidic properties of the catalyst. NiHb(32) exhibits the highest catalytic performance and the lowest apparent activity energy in butene trimerization among the investigated catalysts, due to the reason that it has the proper amount of acid sites on external surface and the proper L/B ratio.

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“…When the sample was exposed to CO (50 Torr) at room temperature, the adsorbed CO band appeared at 2200 cm À1 , as shown in figure 18, curve b. The band might be assigned to the stretching vibration for CO adsorbed on Ni 2þ [51,52]. However, when the sample evacuated at 600°C for 1 h was exposed to CO (100 Torr), the two bands at 2170 and 2122 cm À1 , in addition to the band at 2200 cm À1 , were observed ( figure 18, curve c).…”

Section: Active Sitesmentioning

confidence: 99%

Correlation between acidic properties of nickel catalysts and catalytic activities for ethylene dimerization and butene isomerization

Sohn

2004

Catal Surv Asia

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Catalytic activities of NiO-SiO 2 for ethylene dimerization and butene isomerization run parallel when the catalysts are activated by evacuation at elevated temperatures, giving two maxima in activities. The variations in catalytic activities are closely correlated to the acidity of NiO-SiO 2 catalysts. Catalytic activities of NiO-TiO 2 catalysts modified with H 2 SO 4 , H 3 PO 4 , H 3 BO 3 , and H 2 SeO 4 for ethylene dimerization and butene isomerization were examined. The order of catalytic activities for both reactions was found to be NiO-TiO 2 /SO 2À 4 ) NiO-TiO 2 /PO 3À 4 > NiO-TiO 2 /BO 3À 3 > NiO-TiO 2 /SeO 2À 4 > NiO-TiO 2 , showing clear dependence of catalytic activity upon acid strength. The high catalytic activity of supported nickel sulfate for ethylene dimerization was related to the increase of acidity and acid strength due to the addition of NiSO 4 . The asymmetric stretching frequency of the S@O bonds for supported NiSO 4 catalysts was related to the acidic properties and catalytic activity. That is, the higher the frequency, the larger both the acidity and catalytic activity. For NiSO 4 /Al 2 O 3 -ZrO 2 catalyst, the addition of Al 2 O 3 up to 5 mol% enhanced catalytic activity for ethylene dimerzation and strong acidity gradually due to the formation of Al-O-Zr bond. The active sites responsible for ethylene dimerization consist of a low-valent nickel, Ni þ , and an acid, as evidenced by the IR spectra of CO adsorbed on NiSO 4 /c -Al 2 O 3 and Ni 2p XPS.

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Ligand effects on the redox reactions in nickel- and copper-exchanged zeolites

Abstract: 10) Preliminary results by photolysis methods (P. Gouverneur). (11) J.

Cited by 76 publications

References 6 publications

Importance of Size and Distribution of Ni Nanoparticles for the Hydrodeoxygenation of Microalgae Oil

Importance of Size and Distribution of Ni Nanoparticles for the Hydrodeoxygenation of Microalgae Oil

Trimerization of Butene over Ni-doped Zeolite Catalyst: Effect of Textural and Acidic Properties

Correlation between acidic properties of nickel catalysts and catalytic activities for ethylene dimerization and butene isomerization

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