Journal ArticleDOI
Hydrotalcite-supported palladium catalysts: Part I: Preparation, characterization of hydrotalcites and palladium on uncalcined hydrotalcites for CO chemisorption and phenol hydrogenation
Shankar Narayanan,K. Krishna +1 more
TLDR
Palladium hydrotalcite catalysts are obtained by impregnation of PdCl 2 aqueous solution on HTs and are well characterized by XRD, surface area, IR, SEM, DTA as discussed by the authors.Abstract:
Hydrotalcites (HTs) are prepared by low supersaturation and high supersaturation methods, containing CO 2− 3 , Cl − , SO 2− 4 interlayer anions and with different Al(III)/Al(III)+Mg(II) ( x =0.33 and 0.25) ratios. Palladium hydrotalcite catalysts are obtained by impregnation of PdCl 2 aqueous solution on HTs. Different precursors of palladium are used for loading the metal onto HT prepared at high supersaturation. HT and palladium HTs are well characterized by XRD, surface area, IR, SEM, DTA. CO chemisorption is used to estimate palladium dispersion and metal area. The activity is evaluated for phenol hydrogenation reaction. The selectivity to cyclohexanone is always ≥90% even though phenol conversion varies with metal area.read more
Citations
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Chemistry and materials options of sustainable carbon materials made by hydrothermal carbonization
TL;DR: It will be shown that HTC does not only access carbonaceous materials under comparatively mild hydrothermal conditions, but also replaces the more technical and structurally well-defined charring by a controlled chemical process, leading to very different morphologies with miscellaneous applications, including modern carbon nanocomposites and hybrids.
Journal ArticleDOI
Cyclohexane oxidation continues to be a challenge
Ulf Schuchardt,Dilson Cardoso,Ricardo Sercheli,Ricardo Pereira,Rosenira Serpa da Cruz,Mário César Guerreiro,Dalmo Mandelli,Estevam V. Spinacé,Emerson L. Pires +8 more
TL;DR: In this article, the most interesting systems for the cyclohexane synthesis with different oxidants such as hydrogen peroxide, tert -butyl hydroperoxide and molecular oxygen were reviewed.
Journal ArticleDOI
Hydrotalcite-like anionic clays in catalytic organic reactions
TL;DR: In this paper, a review demonstrates that hydrotalcite-like anionic clays (HTs) can be successfully applied in a broad spectrum of organic reactions, with advantages such as improved activity, selectivity, metal dispersion, less waste production, and an improved recuperation of immobilized catalysts.
Journal ArticleDOI
IR spectroscopy in catalysis
TL;DR: In this paper, a review of the most popular IR spectroscopy applications for catalytic applications is presented, starting from the very general basis of the spectroscopic method applied and focusing on the adsorption of chelating compounds on surfaces of mineral oxides.
References
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Journal ArticleDOI
Hydrotalcite-type anionic clays: Preparation, properties and applications.
Journal ArticleDOI
Catalytic Aluminas: Surface Models and Characterization of Surface Sites
Helmut Knözinger,Paul Ratnasamy +1 more
TL;DR: Aluminas have been used extensively as adsorbenu and active catalysrs and catalyst supponsm the pas as discussed by the authors, and they are used as catalysts for the larter process LS also caralyzed by molybdena-alumina.
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Catalytic reactions by thermally activated, synthetic, anionic clay minerals
TL;DR: The thermal decomposition of a number of anionic clay minerals belonging to the pyroaurites-jogrenite group, such as hydrotalcite (Mg6Al2(OH)16(CO2−3) · 4H2O), results in a product (approximately Mg 6Al2O8(OH−)2) which is a fairly strong base (pKa ≤ 35) and a useful catalyst for vapor-phase aldol condensations as discussed by the authors.
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The nature of the thermal decomposition of a catalytically active anionic clay mineral
TL;DR: In this article, the changes which take place during heat activation of hydrotalcite have been studied by 27Al nuclear magnetic resonance-magic angle spinning, Auger and XPS spectroscopy, transmission electron microscopy, and high resolution nitrogen desorption techniques.
Journal ArticleDOI
Base Catalysis for Fine Chemicals Production: Claisen-Schmidt Condensation on Zeolites and Hydrotalcites for the Production of Chalcones and Flavanones of Pharmaceutical Interest
TL;DR: In this article, an optimized hydrotalcite showed excellent catalytic properties for the synthesis of 2′,4,4′-trimethoxychalcone (Vesidryl), a product of pharmacological interest.