Acidity and basicity of hydrotalcite derived mixed Mg–Al oxides studied by test reaction of MBOH conversion and temperature programmed desorption of NH3 and CO2

Effect of Thermal Treatment on Textural Properties of Natural Montmorillonite

“…The higher temperature caused dehydroxylation reaction to form metakaolin as an effect of broad noisy peaks at 2θ = 15-30°. Kustrowski et al [21] also found when using X-ray on samples of derived hydrotaclites at a higher calcination temperature 600 °C that the formation of mixed oxide phases occurred. The observed XRD patterns of the samples reflections occurred at 2θ 43º and 63° corresponding to a magnesium oxide like phase.…”

Impact of Organic Interlayer Anions in Hydrotalcite Precursor on the Catalytic Activity of Hydrotalcite‐Derived Mixed Oxides

“…This result is consistent with the observations of Kuśtrowski et al, who detected a shorter distance in hydrotalcites with inorganic divalent carbonate in comparison with hydrotalcites containing inorganic monovalent chloride, sulfate, or hydrogen phosphate anions. [6] The charge of the anion seems to be predominant in comparison to the size of the anion, corresponding to the large interlayer distances caused by the Hydrotalcites with aromatic interlayer anions have shown similar tendencies. The interlayer distance decreases with the charge from benzoate to trimesate.…”

“…[4] Thus, the preparation of hydrotalcites with inorganic anions like carbonate, nitrate, sulfate, and halogenides, as well as organic dicarboxylate anions with varying carbon numbers and organic aromatic anions like benzoate and terephthalate have been described in literature. [5][6][7][8][9] The attention hydrotalcite-derived mixed oxides have gained is mainly due to the fact that their catalytic properties can be set and adjusted by the composition of the hydrotalcite precursors during synthesis. Parameters influencing the catalytic properties of hydrotalcite-derived mixed oxides are the nature and ratio of cations within the cationic layers and the nature of anions in the interlayer region of the hydrotalcite precursor as well as the temperature of thermal decomposition, [6,[10][11][12][13] which affects the basic site density.…”

“…[5][6][7][8][9] The attention hydrotalcite-derived mixed oxides have gained is mainly due to the fact that their catalytic properties can be set and adjusted by the composition of the hydrotalcite precursors during synthesis. Parameters influencing the catalytic properties of hydrotalcite-derived mixed oxides are the nature and ratio of cations within the cationic layers and the nature of anions in the interlayer region of the hydrotalcite precursor as well as the temperature of thermal decomposition, [6,[10][11][12][13] which affects the basic site density. [14] The influence of the composition of brucite-type layers in hydrotalcite precursors on the catalytic activity of derived mixed oxides has already been investigated.…”

“…[13] A further study was carried out by Kuśtrowski et al, which focused on the influence of four different inorganic anions and terephthalate on the surface properties and the catalytic activity of the derived mixed oxides in the reaction of 2-methyl-3-butyn-2-ol (MBOH). [6] Towards the goal of sustainable chemistry, transesterification reactions will become more and more important for the conversion of renewable resources, such as the production of biodiesel, [16] which has nearly doubled in Germany from 2005 to 2007. [17] With the history of increasing demand for fuels based on renewable resources, the substitution of the current industrially applied homogeneous base catalysts by heterogeneous catalysts is one of the current challenges.…”