Green synthesis of hydrocalumite-type compounds and their evaluation in the transesterification of castor bean oil and methanol

Effect of microwaves, ultrasounds and interlayer anion on the hydrocalumites synthesis

“…On the whole, all samples showed low surface areas and low pore volumes. This agrees with the results reported by other authors for conventionally prepared hydrocalumites [17,18]. Interestingly, samples HC2 precipitated from nitrate salts using ultrasounds for stirring had the highest surface areas values ( Table 2).…”

“…Hydrocalumites have been extensively used in the immobilization of toxic cations [4][5][6][7][8][9][10][11], the optimization of concrete properties [2,3,[12][13][14], and, in less extent, for catalysis due to their basic properties [15]. The structure of hydrocalumites collapses at temperatures between 400 and 600°C due to the dehydroxylation of their octahedral layers, giving rise to the formation of an amorphous, basic Ca-Al mixed oxide, Ca(Al)O x , which may be also used as catalyst for organic reactions such as the Meerwein-PonndorfVerley reaction [16], the isomerization of 1-butene [17] or the transesterification of castor bean oil and methanol [18].…”

Innovative method for hydrocalumite-like compounds' preparation and their evaluation in the transesterification reaction

“…HLCs obtained by coprecipitation were synthesized by the method described elsewhere (Sánchez-Cantú et al, 2013). 75.884 g of Ca(NO 3 ) 2°4 H 2 O and 60.333 g of Al(NO 3 ) 3°9 H 2 O were dissolved in 417 mL of deionized and decarbonated water (solution A).…”

“…This reaction time was selected since we considered that at low reaction times the basic sites originated after their thermal activation are responsible for carrying out the reaction. At higher reaction times it has been demonstrated that the catalyst suffers a structural transformation caused by the solid's leaching (Sánchez-Cantú et al, 2013). Conversions of 13, 15, 15, 19 and 22% (for CP, HD, THL, DC and DI, respectively) were determined.…”

Catalytic Constructive Deoxygenation of Lignin-Derived phenols: New C–C Bond Formation Processes from Imidazole-Sulfonates and Ether Cleavage Reactions

“…Various ceramic materials have been investigated for the production of biodiesel [106,[109][110][111][112][113][114][115]. Some of these solid catalysts include alkali and alkaline-earth metal carbonates and oxides such as magnesium oxide (MgO), calcium oxide (CaO), barium oxide (BaO), strontium oxide (SrO) [124- transition metal oxides and derivatives (titanium oxide, zinc oxide, mixed oxides catalysts [148][149]); ion exchange resin type acid heterogeneous catalysts [150]; MCM-metal impregnated materials [114]; layered double hydroxides (hydrotalcite-like hydroxides) [151][152][153][154]; hydrocalumite-like compounds [110,155]; supported bases [156][157][158][159][160][161][162][163]; and zeolites [164][165].…”