FTIR Study of Low-Temperature CO Adsorption on MgAl-Hydrotalcite and Its Calcined Forms

Srinivasan, Kannan; Kishore, Dasari; Hadjiivanov, Konstantin; Knözinger, Helmut

doi:10.1021/la030019q

Cited by 17 publications

(18 citation statements)

References 32 publications

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“…Kannan et al used IR spectroscopy of adsorbed CO to monitor the presence of Mg 2 + sites ( % 2160 cm À1 ) and of free Al 3 + sites (2200-2195 cm À1 ) on hydrotalcites calcined and outgassed at different temperatures. [110] Titration: Titration of the basic sites of rehydrated HTs can be made with benzoic acid. [76] In this technique, different amounts of benzoic acid (BA) are added during the reconstruction of the calcined HT.…”

Section: Synthesis Of Hydrotalcitesmentioning

confidence: 99%

“…As explained above, the basicity of the oxygen in a MÀO pair is always connected to the acidity of the partner, that is, the metal (M). Kannan et al [110] have studied a sample with a Mg/Al ratio = 4 that was calcined and outgassed at different temperatures. IR spectroscopy of adsorbed CO revealed a principal carbonyl band around 2160 cm À1 that was assigned to CO adsorbed on Mg 2 + sites.…”

Section: Tuning and Exploiting The Basicity Of Hydrotalcite-based Matmentioning

confidence: 99%

“…Kannan et al. used IR spectroscopy of adsorbed CO to monitor the presence of Mg 2+ sites (≈2160 cm −1 ) and of free Al 3+ sites (2200–2195 cm −1 ) on hydrotalcites calcined and outgassed at different temperatures 110…”

Section: Probing the Basicity Of Hydrotalcitesmentioning

confidence: 99%

“…As explained above, the basicity of the oxygen in a MO pair is always connected to the acidity of the partner, that is, the metal (M). Kannan et al 110. have studied a sample with a Mg/Al ratio=4 that was calcined and outgassed at different temperatures.…”

Section: Tuning and Exploiting The Basicity Of Hydrotalcite‐based Matmentioning

confidence: 99%

See 3 more Smart Citations

Exploring, Tuning, and Exploiting the Basicity of Hydrotalcites for Applications in Heterogeneous Catalysis

Debecker

Gaigneaux

Busca

2009

Chemistry A European J

474

265

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Basic catalysis! The basic properties of hydrotalcites (see picture) make them attractive for numerous catalytic applications. Probing the basicity of the catalysts is crucial to understand the base-catalysed processes and to optimise the catalyst preparation. Various parameters can be employed to tune the basic properties of hydrotalcite-based catalysts towards the basicity demanded by each target chemical reaction.Hydrotalcites offer unique basic properties that make them very attractive for catalytic applications. It is of primary interest to make use of accurate tools for probing the basicity of hydrotalcite-based catalysts for the purpose of 1) fundamental understanding of base-catalysed processes with hydrotalcites and 2) optimisation of the catalytic performance achieved in reactions of industrial interest. Techniques based on probe molecules, titration techniques and test reactions along with physicochemical characterisation are overviewed in the first part of this review. The aim is to provide the tools for understanding how series of parameters involved in the preparation of hydrotalcite-based catalytic materials can be employed to control and adapt the basic properties of the catalyst towards the basicity demanded by each target chemical reaction. An overview of recent and significant achievements in that perspective is presented in the second part of the paper.

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Section: Synthesis Of Hydrotalcitesmentioning

confidence: 99%

Section: Tuning and Exploiting The Basicity Of Hydrotalcite-based Matmentioning

confidence: 99%

Section: Probing the Basicity Of Hydrotalcitesmentioning

confidence: 99%

Section: Tuning and Exploiting The Basicity Of Hydrotalcite‐based Matmentioning

confidence: 99%

See 2 more Smart Citations

Exploring, Tuning, and Exploiting the Basicity of Hydrotalcites for Applications in Heterogeneous Catalysis

Debecker

Gaigneaux

Busca

2009

Chemistry A European J

474

265

View full text Add to dashboard Cite

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“…The probable reason for such a drastic drop in the conversion may be structural change; wherein complete destruction of layered structure occurs at higher temperatures (>500°C), forming mixed metal oxide. Our recent study on probing the acid-base characteristics of calcined MgAl-HT through low temperature CO adsorption by FT-IR showed the presence of Lewis base sites at those temperatures [104]. In other words, eugenol isomerization is not effective on Lewis basic sites and requires Bronsted basic sites (hydroxylated layered network), which abstract protons of methylene carbon to assist in isomerization.…”

Section: Isomerization Of Eugenol Over Mgal Hydrotalcites and Their Mmentioning

confidence: 99%

Catalytic applications of hydrotalcite-like materials and their derived forms

Srinivasan

2006

Catal Surv Asia

Self Cite

109

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Hydrotalcite-like (HT-like) materials have been studied extensively in the last three decades. Although these materials initially perceived as potential anion exchangers, unrelenting efforts have also been attempted to use them as catalytic materials or as catalytic supports. There are varied ways by which one can use them for catalysis viz.; 1. Use them in as-synthesized form 2. Use them after calcining where the structural integrity of layered lattice is lost 3. Use the interlayer as functional spaces with moieties of catalytic interest 4. Use them after destruction or delamination and restructuring and 5. Use them as support or matrix. In this review, we are reporting the catalytic applications of HT-like materials and their derived forms carried out in our research group for the last 15 years in these various ways, covering reactions such as nitrous oxide decomposition, selective oxidation of organic compounds of industrial relevance and base-catalyzed isomerization of chemicals of perfumery interest. Although this review primarily focuses on our work, wherever applicable, related or relevant works from other groups are also presented to bestow comprehensiveness.

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