Thermodynamic properties of solid Ni-Zn alloys by atomic absorption

Anantatmula, R.P.; Masson, D. Bruce

doi:10.1007/bf02644656

Cited by 39 publications

(7 citation statements)

References 12 publications

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“…For this reason, for the samples with lower Zn/Ni atomic relations, the paths for the first coordination shell of the absorbing atom in the bimetallic structures (Ni-Zn and Zn-Ni) were calculated from the Ni fcc structure filled with Zn atoms at random positions in proportion with the Zn/Ni atomic ratio of each sample. For sample NiZn0.5/SC, the β 1 phase of the NiZn alloy was used [25]. Fig.…”

Section: Catalyst Characterization Resultsmentioning

confidence: 99%

“…All data fits were conducted between 1.0-3.0 Å in r-space and were generated by Fourier filtering the k 3 -weighted EXAFS over 2-13 Å −1 in kspace with a Hanning window. The theoretical scattering path amplitudes and phase shifts used in these fits were calculated from crystallographic structures of either monometallic lattices (for Ni-Ni [ICSD number: 64989] and Zn-Zn [ICSD number: 64990] paths) or mixed phase lattices (for Ni-Zn and Zn-Ni [25] paths), all of which were facecentered cubic (fcc). EXAFS data extracted from bimetallic samples were fit simultaneously at both metal edges, thus ensuring consistency in the interatomic distances and Debye-Waller factors of bimetallic paths.…”

Section: Characterizationmentioning

confidence: 99%

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Improvement of the catalytic activity of Ni/SiO 2 -C by the modification of the support and Zn addition: Bio-propylene glycol from glycerol

Gatti

Mizrahi

Ramallo-López

et al. 2017

Applied Catalysis A: General

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In previous studies, we prepared Ni catalysts supported on a silica-carbon composite which is selective for obtaining 1,2-propylene glycol (1,2-PG). In order to improve the activity levels of this catalyst, in the present work we propose to modify the catalyst formulation by means of two strategies: on the one hand, to modify the acidity of the catalyst through the functionalization of the carbon support and, on the other hand, to modify the metallic phase by the addition of Zn from a controlled preparation technique (Surface Organometallic Chemistry on Metals), which allows the selective addition of small amounts of modifier on the metallic particles. The functionalization of the SC support at 80°C employing HNO 3 at 60 wt% as oxidizing agent allowed increasing the number of surface acid sites that provide Lewis-type acidity without loss of specific surface area. The addition of 1.1-1.8 wt% of Zn (which corresponds to catalysts NiZn0.2/SC and NiZn0.32/SC) generates the formation of an active site composed of an α-NiZn alloy responsible for the increase in activity. When the addition of Zn is 2.8 wt% (which corresponds to catalyst NiZn0.5/SC), the generation of a new tetragonal phase of β 1-NiZn would cause the decrease of catalytic activity. These results indicate that the Zn addition has a more significant effect upon the activity and selectivity on the CeO bond cleavage reactions than the effect of the support acidity upon the dehydration activity.

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Section: Catalyst Characterization Resultsmentioning

confidence: 99%

Section: Characterizationmentioning

confidence: 99%

Improvement of the catalytic activity of Ni/SiO 2 -C by the modification of the support and Zn addition: Bio-propylene glycol from glycerol

Gatti

Mizrahi

Ramallo-López

et al. 2017

Applied Catalysis A: General

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“…All masses were weighed to an accuracy of 0.0001 g. Each alloy mixture was put in quartz tube, rinsed three times with pure argon, and sealed under vacuum of 0.01 Pa. Then it was heated to 1100°C and kept at this temperature for 30 h, followed by quenching in water using a bottomquenching technique [32] to minimize Zn loss and reduce sample porosity. The quenched samples were sealed again [28] NiZn (b 1 ) AuCu P4/mmm 3.898 3.1927 [29] NiZn 3 (c) NiZn 3 Ab2m 33.32 8.869 12.49 [30] NiZn 8 (d) NiZn 8 C2/m 13.37 7.47, b = 111.3°7.65 [31] Section I: Basic and Applied Research individually in evacuated quartz tubes, and annealed at 450°C for 30 days to ensure the establishment of equilibrium state. The treatment was completed with rapid water quenching to preserve the equilibrium state at 450°C.…”

Section: Methodsmentioning

confidence: 99%

The 450 °C Isothermal Section of the Zn-Bi-Ni System

Liu

Yin

et al. 2008

J Phs Eqil and Diff

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The isothermal section of the Zn-Bi-Ni ternary system at 450°C was determined experimentally using the equilibrated alloys approach. The specimens were investigated by means of optical microscopy, scanning electron microscopic/energy-dispersive spectrometric analysis and x-ray diffraction. Six three-phase regions exist in this isothermal section. The L-Bi phase is in equilibrium with all phases of Ni-Zn binary system except the a-Ni phase. Experimental results indicate that the third element, Zn or Bi, is almost insoluble in the Bi-Ni or Ni-Zn intermetallic compounds.

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“…On the contrary, the Ni-Zn, Ni-Sb, Zn-Sb binary systems are well studied and described in the literature [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Crystallographic data of the binary compounds existing in the Ni-Zn, Ni-Sb, Zn-Sb systems are shown in Table 1.…”

Section: Introductionmentioning

confidence: 99%