MgFeCe Ternary Layered Double Hydroxide as Highly Efficient and Recyclable Heterogeneous Base Catalyst for Synthesis of Dimethyl Carbonate by Transesterification

Abstract

A series of Mg3:Fex+Ce1-x LDHs (3:1) were synthesized by co-precipitation method by varying molar ratio of Fe:Ce between 1:0 to 0:1 (LDH-1 to LDH-6). All synthesized LDHs were characterized by XRD, FT-IR, TEM, N2 sorption, benzoic acid titration and XPS in detail and evaluated for selective synthesis of dimethyl carbonate by transesterification of ethylene carbonate with methanol. It was demonstrated that the structural and basic properties of synthesized LDHs were strongly dependent on the Fe:Ce molar ratio (Ce concentration). The correlation between their physicochemical properties and catalytic performance was studied in detail. Among all synthesized LDHs the best result was obtained with LDH-3 (Fe:Ce=0.85:0.15) where LDH structure remained intact, and showed high number of strong basic sites on LDH surface. LDH-3 was recycled 7 times while maintaining high catalyst activity and selectivity towards DMC. The obtained results elucidate the important role of Ce in modifying the basic properties of LDH in enhancing the catalytic activity for DMC synthesis.

Flame retardancy of silicone rubber foam containing modified hydrotalcite

“…The characteristic absorption peak at 1379 cm −1 is attributed to the interlayer anion carbonate, and the CO 3 2− (1433 cm −1 ) peak position of the absorption peak in CaCO 3 has a red shift, indicating a strong hydrogen interaction between CO 3 2− and H 2 O in the layers. This finding also shows that CO 3 2− successfully enters the interlayer containing different Ce 3+ LDHs 29,30 . In the range of 1050–400 cm −1 , interlayer lattice (ZnO, CeO, CeOZn, MgO, and AlO) vibration peaks are observed.…”

Template-Free Preparation of α-Ni(OH)2 Nanosphere as High-Performance Electrode Material for Advanced Supercapacitor

“…The weak peak at 635 cm −1 is assigned to the Ni-O bending vibration, confirming the successful preparation of Ni(OH) 2 [38]. The peak at ~1390 cm −1 is attributed to the C-O stretching vibration, indicating the intercalation of carbonate anions in the interlamination due to the dissociation of the urea [23,39]. In addition, two bands at 3445 and 1630 cm −1 are related to the O-H vibration from the hydroxyl groups or adsorbed water molecules of Ni(OH) 2 .…”

Mechanism and regeneration of sulfur-poisoned Mn-promoted calcined NiAl hydrotalcite-like compounds for C3H6-SCR of NO

“…The characteristic peaks located at 11,22,35,38, and 46 are assigned to the hydrotalcite structure (JCPDS 22-700). [22][23][24] Meanwhile, there are no additional peaks derived from Mn species for MnNiAl-HT samples, suggesting that Mn is well dispersed on the surface of the carrier. The unit cell parameters a and c of the hydrotalcite can be calculated assuming a 3R stacking sequence; therefore, a ¼ 2d 110 and c ¼ d 003 + 2d 006 + 3d 009 , where the value of a is the average distance of two metal cations in adjacent unit cells and c is the interlayer distance regulated by the size and charge of the anion placed between the brucite-like layers.…”