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Synthetic hydrotalcites from different routes and their application as catalysts and gas adsorbents: a review

“…The use of microwave radiation as a source of heating not only reduces the aging time considerably but also enhances the kinetics of crystallization. [76,91] A well-crystallized material was reportedly obtained in 12 min, in comparison with 1530 min for a conventionally synthesized samples. [60] The extent of the crystallization rate upon irradiation was influenced largely by the nature of the trivalent cation present in the HT-like network and the orientation of water molecules in the interlayer spaces.…”

Increasing the basicity and catalytic activity of hydrotalcites by different synthesis procedures

“…Other authors have reported a crystallization rate enhancement of LDHs using microwaves [12,13]. More specifically, in the case of Mg/Al LDHs, Fetter et al [14] have found that microwave irradiation of the coprecipitated gel allows well-crystallized and pure hydrotalcite-like phases to be obtained, and the ageing time can be reduced from 18-24 h to 2-10 min. Moreover, these authors have found that hydrotalcites obtained by this method present smaller crystallite sizes and higher specific surface areas than conventional samples, synthesized aging of the gels at 423 K for 24 h. Recently, Tichit et al [15] have studied the structural and acid-base properties of Mg/Al and Mg/Ga LDH obtained by microwave irradiation of the coprecipitated gels, that were compared with those conventionally aged by prolonged hydrothermal treatment (18 h at room temperature).…”

Tuning Nanomaterials' Characteristics by a Miniaturized In‐Line Dispersion–Precipitation Method: Application to Hydrotalcite Synthesis

“…[6,7] They are often synthesized by batch coprecipitation and several parameters have been varied in the preparation in order to alter the physicochemical characteristics of the final product, such as conducting the precipitation at different pH, [3] levels of supersaturation, [6] and temperature [8] or by means of sol-gel synthesis. [9] Postsynthesis modifications such as aging and hydrothermal treatments have also been performed, [8,10,11] in conjunction with application of microwaves [12,13] or ultrasound. [14] However, despite much effort, a solid understanding of the nucleation and crystal-growth phenomena associated with the precipitation and post-treatments in order to tune hydrotalcite characteristics is not yet achieved.…”