Surface properties of the Ni-silica gel catalyst precursors for the vegetable oil hydrogenation process: N2 sorption and XPS studies

Nikolova, D.; Krstić, Jugoslav; Spasov, L.; Simeonov, Danail B.; Lončarević, Davor; Stefanov, P.; Jovanović, D.

doi:10.1134/s0036024411130188

Cited by 6 publications

(5 citation statements)

References 8 publications

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“…The chemical shift of the Ni 2p 3/2 peak toward higher binding energy values for the Ni/SiG-B sample is assigned to the stronger interaction between the Ni 2+ species and the SiG-B support. On the contrary, the observed shift toward lower binding energies for the Ni-SiG-C sample suggests weakening interaction between the Ni 2+ supported phase and the SiG-C support [68]. Table 7 reveals the variations of the Ni/Si ratio suggesting the different dispersion of the Ni 2+ species in analyzed samples, as previously shown in the H 2chemisorption results of the corresponding precursor samples (see Table 6).…”

Section: X-ray Photoelectron Spectroscopy (Xps)supporting

confidence: 62%

“…The crude material was mechanically, chemically and thermally treated to obtain the desired support characteristics. Three types of commercial silica gel with different textural characteristics (silica gel-A, silica gel-B, silica gel-C, silica gel = SiG hereinafter expressed as SiG-A, SiG-B and SiG-C, see [68]), produced in Bulgaria, were used for the preparation of the nickel-based catalyst supported on silica gel. Expanded perlite (PF, commercial product Perfit PF-295) supplied with the courtesy of Termika Zrenjanin, Serbia, was used for synthesis of nickel-based catalysts on perlite.…”

Section: Materials Usedmentioning

confidence: 99%

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Supported Nickel-Based Catalysts for Partial Hydrogenation of Edible Oils

Stanković¹,

Krstić²,

Gabrovska³

et al. 2017

New Advances in Hydrogenation Processes - Fundamentals and Applications

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Nickel-based catalysts, supported on diatomite, silica gel and perlite, with high nickel loadings, have been prepared by precipitation-deposition method. Various nickel precursor salts were used for the preparation of catalyst precursors. In the precursor state, the catalysts were characterized using nitrogen physisorption, mercury porosimetry, infrared, and X-ray diffraction spectroscopy. The reducibility of catalyst precursors was evaluated using hydrogen temperature programmed reduction. Hydrogen chemisorption and X-ray photoelectron spectroscopy measurements were performed with the aim of characterizing the chemical state of the catalyst precursors. This research was focused on the study of some major factors on the state, dispersion and reducibility of a deposited Ni 2+ phase by the combined use of mentioned experimental techniques. We have examined the influence of the nature of support and the use of modifiers on activity of nickel-based catalysts in the partial hydrogenation of sunflower and soybean oils. Nitrogen physisorption and mercury porosimetry data showed that synthesis operating conditions and pore structure of supports have a profound effect on the textural properties of catalyst precursors. The analysis of infrared and X-ray diffraction spectra showed the existence of chemical species and phases which indicate the different extent of interaction between the support and the active metal. Temperature programmed reduction study revealed that the reduction features depend on the identity of the nickel precursor salt and its interaction with the support. A stronger interaction of the supported Ni 2+ phase with support hinders the reduction of catalyst precursors. Hydrogen chemisorption results showed the presence of nickel crystallites varying from 5 to 47 nm in size. The X-ray photoelectron spectroscopy data confirmed the formation surface species with different strength of interaction and different nickel crystallite sizes. The hydrogenation results showed significant differences, depending on the support and the modifier, as well as structural characteristics of reduced catalyst precursors. The results show the importance of modifiers in the control of the activity and selectivity of the partial hydrogenation

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Section: X-ray Photoelectron Spectroscopy (Xps)supporting

confidence: 62%

Section: Materials Usedmentioning

confidence: 99%

Supported Nickel-Based Catalysts for Partial Hydrogenation of Edible Oils

Stanković¹,

Krstić²,

Gabrovska³

et al. 2017

New Advances in Hydrogenation Processes - Fundamentals and Applications

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show abstract

“…The binding energy of Ni 2p in the region near 856.54 eV is attributed to Ni 2+ ions, whereas that around 862.36 eV is known as a satellite peak that appears as a result of multielectron excitation 23 . The shift of the peak towards higher binding energy values for Ni-PTA/Al 2 O 3 is assigned to the stronger interaction between Ni 2+ and the alumina surface 24 .…”

Section: Resultsmentioning

confidence: 87%

Hydroprocessing of Jatropha Oil for Production of Green Diesel over Non-sulfided Ni-PTA/Al2O3 Catalyst

Liu

Lei

et al. 2015

Sci Rep

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The non-sulfided Ni-PTA/Al2O3 catalyst was developed to produce green diesel from the hydroprocessing of Jatropha oil. The Ni-PTA/Al2O3 catalyst was prepared by one-pot synthesis of Ni/Al2O3 with the co-precipitation method and then impregnanting Ni/Al2O3 with PTA solution. The catalysts were characterized with BET, SEM-EDX, TEM, XRD, XPS, TGA and NH3-TPD. The Ni and W species of the Ni-PTA/Al2O3 catalyst were much more homogeneously distributed on the surface than that of commercial Al2O3. Catalytic performance in the hydroprocessing of Jatropha oil was evaluated by GC. The maximum conversion of Jatropha oil (98.5 wt%) and selectivity of the C15-C18 alkanes fraction (84.5 wt %) occurred at 360 °C, 3.0 MPa, 0.8 h−1. The non-sulfided Ni-PTA/Al2O3 catalyst is more environmentally friendly than the conventional sulfided hydroprocessing catalyst, and it exhibited the highest catalytic activity than the Ni-PTA catalyst supported with commercial Al2O3 grain and Al2O3 powder.

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“…It was found that the silica gels are distinguished from one another in their textural characteristics (Nikolova et al, 2011). The differences in texture parameters of supports may lead to obtaining catalysts with different activities (González-Marcos et al, 1997), as can also be obtained with different reducibility of catalyst precursors.…”

Section: Precursors and Catalysts Synthesismentioning

confidence: 98%