Vibrational spectroscopy study of zinc-containing mixed oxides as regenerable sulphur sorbents at high temperature

Ibarra, JoséV.; Cilleruelo, Cristina; García, Enrique; Pineda, Miguel; Palacios, J.M.

doi:10.1016/s0924-2031(97)00039-8

Cited by 15 publications

(9 citation statements)

References 13 publications

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“…The absorption peaks of ZnO appeared at 437, 498, and 534 cm -1 , those of TiO 2 at 510−710 cm -1 , and those of Co 3 O 4 at 570 and 662 cm -1 . These spectra agreed well with the results of the works of Ibarra et al and Nyquist and Kagel. , Absorption peaks for ZT and ZTC sorbents before/after sulfidation and regeneration under high-temperature conditions are shown in Figure . No differences between the two sorbents (ZT vs ZTC) were observed.…”

Section: Resultssupporting

confidence: 90%

A Study of Zn−Ti-Based H₂S Removal Sorbents Promoted with Cobalt Oxides

Jun

Lee

Ryu

et al. 2001

Ind. Eng. Chem. Res.

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Modification of conventional zinc titanate (ZT) sorbents to increase their reactivity and stability during multiple cycles of sulfidation/regeneration at high and middle temperatures was pursued by addition of Co 3 O 4 . Moreover, evaluation of the modified zinc titanates (ZTC) was conducted using several instruments such as an X-ray diffractometer, Fourier transform infrared spectrometer, scanning electron microscope, and so on. The ZTC sorbents prepared by the physical mixing of the ZT sorbent with 25 wt % of Co 3 O 4 showed an excellent sulfur-removing capacity and no deactivation even after multiple cycles of sulfidation/regeneration in both high-and middle-temperature conditions. The cobalt permeated the Zn 2 TiO 4 lattice, leading to a new spinel phase, ZnCoTiO 4 . It worked not only as an active site during the sulfidation process but also as a support to prevent zinc migration to the outside of the sorbents and to minimize volume expansion/contraction. Under middle-temperature conditions, the phase separation of the ZTC sorbent including a cobalt oxide intermediate in addition to the ZnCoTiO 4 spinel structure was observed. Also, the cobalt additive increased the regeneration capacity of Zn-based sorbents because it played an important role as the catalyst for oxidation.

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Section: Resultssupporting

confidence: 90%

A Study of Zn−Ti-Based H₂S Removal Sorbents Promoted with Cobalt Oxides

Jun

Lee

Ryu

et al. 2001

Ind. Eng. Chem. Res.

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“…In the case of the ZT-700 and Z-700 sorbents, the wavenumbers of 226, 448 and 610 cm −1 could be assigned as titanium oxide with a rutile structure. These results were identified with the XRD patterns of titanium oxide after sulfidation of the sorbents reported in a previous paper [26].…”

Section: The Crystal Structures Of the Sorbentssupporting

confidence: 81%

A study of the sulfidation and regeneration reaction cycles of Zn-Ti-based sorbents with different crystal structures

Jung

Park

Lee³

et al. 2010

Korean J. Chem. Eng.

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The reaction cycles of the sulfidation and regeneration of Zn-Ti-based sorbents prepared by a physical mixing method (ZT-700 and ZT-1000) or co-precipitation method (ZT-cp) were tested in a fixed bed micro-reactor at middle temperature (Sulfidation; 480 o C, regeneration; 580 o C). The ZnS produced during sulfidation from the Zn 2 TiO 4 with a spinel structure (ZT-1000, ZT-cp) was easily regenerated even at 550 o C, while the ZnS produced from the ZnO with a hexagonal structure (ZT-700) needed a temperature higher than 610 o C. After regeneration, each sorbent was restored to its original crystal structure. The differences in the regeneration properties and the reaction cycles of the sorbents were related to the original crystal structures rather than to the physical properties such as pore volume and surface area. To study these differences further, FT-IR, FT-Raman, XRD and TPR were used, and their results including the reaction cycles of the sulfidation and regeneration on the Zn-Ti based sorbents with different crystal structures were discussed.

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“…The 790 known A 2 BX 4 compounds [1][2][3][4][5][6][7][8][9][10][11][12][13] are distributed into 44 different crystal structure types as listed in Tables 1 and 2 (the Supporting Information lists the compounds belonging to each of the different structure types). This group of compounds exhibits significant chemical diversity, including chalcogen anions (X ¼ O, S, Se, Te) as well as halides (X ¼ F, Cl, Br, I), nitrides (X ¼ N), cyanides (X ¼ CN), and even nitrites (X ¼ NO 2 ).…”

Section: Introductionmentioning

confidence: 99%

Diagrammatic Separation of Different Crystal Structures of A₂BX₄ Compounds Without Energy Minimization: A Pseudopotential Orbital Radii Approach

Zhang¹,

Zunger²

2010

Adv Funct Materials

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The A2BX4 family of compounds manifest a wide range of physical properties, including transparent conductivity, ferromagnetism, and superconductivity. A 98% successful diagrammatic separation of the 44 different crystal structures of 688 oxide A2BX4 compounds (96% for 266 oxide‐only) is described by plotting the total radius of the A atom RA versus the radius of the B atom RB for many A2BX4 compounds of known structure types and seeking heuristically simple, straight boundaries in the RA versus RB plane that best separate the domains of different structure types. The radii are sums RA = Rs(A) + Rp(A) of the quantum‐mechanically calculated “orbital radii” Rs(Rp), rather than empirical radii or phenomenological electronegativity scales. These success rates using first‐principles orbital radii uniformly exceed the success rates using classic radii. Such maps afford a quick guess of the crystal structure of a yet unmade A2BX4 compound by placing its atomic orbital radii on such maps and reading off its structure type.

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Vibrational spectroscopy study of zinc-containing mixed oxides as regenerable sulphur sorbents at high temperature

Cited by 15 publications

References 13 publications

A Study of Zn−Ti-Based H₂S Removal Sorbents Promoted with Cobalt Oxides

A Study of Zn−Ti-Based H₂S Removal Sorbents Promoted with Cobalt Oxides

A study of the sulfidation and regeneration reaction cycles of Zn-Ti-based sorbents with different crystal structures

Diagrammatic Separation of Different Crystal Structures of A₂BX₄ Compounds Without Energy Minimization: A Pseudopotential Orbital Radii Approach

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Vibrational spectroscopy study of zinc-containing mixed oxides as regenerable sulphur sorbents at high temperature

Cited by 15 publications

References 13 publications

A Study of Zn−Ti-Based H2S Removal Sorbents Promoted with Cobalt Oxides

A Study of Zn−Ti-Based H2S Removal Sorbents Promoted with Cobalt Oxides

A study of the sulfidation and regeneration reaction cycles of Zn-Ti-based sorbents with different crystal structures

Diagrammatic Separation of Different Crystal Structures of A2BX4 Compounds Without Energy Minimization: A Pseudopotential Orbital Radii Approach

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A Study of Zn−Ti-Based H₂S Removal Sorbents Promoted with Cobalt Oxides

A Study of Zn−Ti-Based H₂S Removal Sorbents Promoted with Cobalt Oxides

Diagrammatic Separation of Different Crystal Structures of A₂BX₄ Compounds Without Energy Minimization: A Pseudopotential Orbital Radii Approach