Characteristics of NiO present in solids obtained from hydrotalcites based on Ni/Al and Ni-Zn/Al

Fuentes, Edgardo Meza; Ruiz, Jorge; Santos, Maria do Carmo Rangel

doi:10.15446/dyna.v86n210.78559

Cited by 7 publications

(2 citation statements)

References 30 publications

(41 reference statements)

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“…The intensity of the latter band decreases with increasing alumina content, changes can be seen in zoomed Figure 7d. Decrease or disappearance of this band is reported for NiO [47], NiO/Al 2 O 3 [52] and for Ni-Al hydrotalcites [48]. The decrease in intensity is attributed to a decrease in crystallite size, metal support interaction or particle size of NiO, all of which reflect in better dispersion.…”

Section: Raman Spectroscopymentioning

confidence: 84%

Transformation of Styrene Oxide on Bi-Functional Ni, Co and Cu Catalysts Supported on Zirconia-Alumina: Effect of Depositing Zirconia on Alumina

Pathan,

K. Modi,

Basrur

2023

Univers. J. Catal. Sci.

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2-phenyl ethanol (2-PEA) and 2-phenylacetaldehyde (PAA) are important perfumery chemicals which are prepared by hydrogenation and isomerization of styrene oxide (SO) respectively. Activities of Ni, Co and Cu supported on a set of zirconia-alumina supports with varying ZrO2:Al2O3 molar ratio are compared for these reactions. Zirconia was deposited on γ-alumina by deposition-precipitation. All catalysts were characterized by XRD, NH3-TPD, H2-TPR, N2 physisorption, XPS and Raman spectroscopy. Increasing the zirconia content significantly influenced catalyst characteristics. These are correlated with reactivity: i) surface concentration of Ni, Co and Cu (XPS) decreased, which affected conversion of styrene oxide and selectivity to 2-PEA ii) 1 1 1 plane of Cu (XRD) was suppressed which enhanced selectivity of styrene by-product relative to 2-PEA iii) acidity (NH3-TPD) decreased, which adversely affected yield of PAA. Product space time yields (STY) of 2-PEA and PAA correlated well with surface concentration of active metals (XPS) and acidity (NH3-TPD) respectively. Various by-products were identified. Styrene appeared to form by deoxygenation of SO. TPR and Raman spectroscopy indicated strong interaction of Co and Ni with alumina while Cu showed strong interaction with zirconia. This reflected in their XRD crystallite size. Cu has different electronic properties than Co and Ni, which reflected in differences in their behavior. This study directly compares the performance of these transition metals in continuous flow studies and correlates catalyst characteristics with reactivity.

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Section: Raman Spectroscopymentioning

confidence: 84%

Transformation of Styrene Oxide on Bi-Functional Ni, Co and Cu Catalysts Supported on Zirconia-Alumina: Effect of Depositing Zirconia on Alumina

Pathan,

K. Modi,

Basrur

2023

Univers. J. Catal. Sci.

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“…?, in these materials, this type of NiO particles is higher than that recorded by material A05-500, revealing that the presence of zinc partially preventing the interaction between NiO units and the aluminum oxide-based support. Only the AZ10-500 material exhibited NiO in a weak interaction with the support [2,40,42].…”

Section: Resultsmentioning

confidence: 99%

Study of NiO/Al2O3 and NiO/Zn-Al2O3 catalysts for water gas shift reaction

Meza-Fuentes,

Rodríguez Ruíz,

Castellar Arroyo

et al. 2023

Universitas Scientiarum

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Nickel-based catalysts are of great importance for the generation of hydrogen from natural gas. Within this process, the conditions in which commercial NiO/Al2O3 is converted to Ni0/Al2O3 catalyst should be further investigated. A widely used technique to identify Ni2+ reduction conditions and the different compounds or types of particles in which this element is present is temperature-programmed reduction. In this work, the type of nickel oxide particles occurring on Al2O3 and ZnO-Al2O3-based supports were studied by different techniques, such as energy-dispersive X-ray spectroscopy, FTIR, the BET method, X-ray diffraction (XRD), and Temperature Programmed Reduction (TPR). All materials were evaluated in the water gas shift reaction (WGS), and the influence of their characteristics on the catalytic activity was assessed. Solids were prepared at different temperatures and Ni/Zn molar ratios. The results showed the presence of NiO in all materials, as well as the presence of ZnO, NiAl2O4, and ZnAl2O4 in materials prepared at higher temperatures. In all the materials calcined at the lowest temperature, the formation of NiO particles that fail to interact with the supports was prioritized. As the calcination temperature increased, NiO aggregates were formed, which, to a greater degree, interacted with the supports, whereby nickel aluminate was detected in all materials prepared at 750 °C. Zinc increased the selectivity but decreased specific surface area and activity through the WGS reaction. The solid labeled AZ15-500 showed higher activity and selectivity, reaching values of 100% for the water gas shift reaction.

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Preparation of M–Al and M–Ca–Al (M: Sr, Cd, Ni, Ca, and Co) mixed oxides derived from LDH precursors as the high performance heterogeneous base catalysts for efficient synthesis of chalcones

Nazari,

Mahdavi,

Khosravi

2024

J IRAN CHEM SOC

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Characteristics of NiO present in solids obtained from hydrotalcites based on Ni/Al and Ni-Zn/Al

Cited by 7 publications

References 30 publications

Transformation of Styrene Oxide on Bi-Functional Ni, Co and Cu Catalysts Supported on Zirconia-Alumina: Effect of Depositing Zirconia on Alumina

Transformation of Styrene Oxide on Bi-Functional Ni, Co and Cu Catalysts Supported on Zirconia-Alumina: Effect of Depositing Zirconia on Alumina

Study of NiO/Al2O3 and NiO/Zn-Al2O3 catalysts for water gas shift reaction

Preparation of M–Al and M–Ca–Al (M: Sr, Cd, Ni, Ca, and Co) mixed oxides derived from LDH precursors as the high performance heterogeneous base catalysts for efficient synthesis of chalcones

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