How the acido-basic properties of Mg silicates and clays govern the catalytic mechanism of transesterification reactions

Abstract

Choosing acido-basic properties of magnesium silicates to tune the transesterification mechanism in the liquid phase.

Few-Layer ZnIn2S4/Laponite Heterostructures: Role of Mg2+ Leaching in Zn Defect Formation

“…The position of the peak ascribed to the (110) plane of ZnIn 2 S 4 also shifts for ZIS-Lap toward an angle that fits tetragonal In 2 S 3 as well; however, the breadth of this peak and the overlap with ZnIn 2 S 4 and ZnS give less clarity than the prior case (Figure e). The addition of 0.2 mmol of Mg also results in peaks at 19.70, 35.15, and 60.85°, corresponding to the (02,11), (20,13), and (060) planes of Lap (PDF 009-0031), respectively. , Interestingly, the peaks corresponding to Lap appear clearly with 0.2 mmol of Mg 2+ but diminish with decreasing Mg 2+ concentration, suggesting that increased Mg 2+ improves Lap stability at low concentrations (Figure c).…”

“…The addition of 0.2 mmol of Mg also results in peaks at 19.70, 35.15, and 60.85°, corresponding to the (02,11), (20,13), and (060) planes of Lap (PDF 009-0031), respectively. 36,37 Interestingly, the peaks corresponding to Lap appear clearly with 0.2 mmol of Mg 2+ but diminish with decreasing Mg 2+ concentration, suggesting that increased Mg 2+ improves Lap stability at low concentrations (Figure 3c). Elemental compositions of ZIS-Lap nanohybrids were measured by energy-dispersive X-ray spectroscopy (EDX).…”

Few-Layer In2S3 in Laponite Interlayers: A Colloidal Route Toward Heterostructured Nanohybrids with Enhanced Photocatalysis

“…Pure In 2 S 3 shows several diffraction peaks at 14.21, 23.35, 27.41, 28.64, 33.18, 36.28, 40.91, 43.61, 47.74, 50.11, 53.73, 55.90, 56.61, 59.47, 61.42, 64.72, and 66.62°, indexed to (111), (220), (311), (222), (400), (331), (422), (511), (440), (531), (620), (533), (622), (444), (711), (642), and (731) crystal planes of cubic β-In 2 S 3 (PDF 84-1385), respectively. , As shown in Figure a, pure Lap has a broad peak at ∼6.76°, which gives a basal spacing of 1.30 nm by Bragg’s Law. Further peaks were observed at 19.70, 28.04, 35.15, 53.52, and 60.85°, corresponding to the planes (02,11), (005), (20,13), (24,31), and (060) of Lap (PDF 009-0031), respectively. , …”

“…Further peaks were observed at 19.70, 28.04, 35.15, 53.52, and 60.85°, corresponding to the planes (02,11), (005), (20,13), (24,31), and (060) of Lap (PDF 009-0031), respectively. 54,55 The peaks attributed to the (400) and (511) planes of In 2 S 3 in IS-LAP samples become markedly weaker and disappear with increasing CPC (Figure 4b). As noted above, the loss of the (400) peak in the XRD spectra with increasing CPC is also observed via HRTEM; while the (400) lattice fringe was observed for pure In 2 S 3 (Figure 2f), it was not observed for IS-LAP samples (Figure 2b,d).…”

Neighboring Group Participation and Internal Catalysis Effects on Exchangeable Covalent Bonds: Application to the Thriving Field of Vitrimer Chemistry

“…Transesterification was studied in polymers in the second half of the 20th century, as the exchange reaction is more significant in bulk materials; ,,, then this reaction regained popularity among scientists with the development of biodiesel and biofuels. Recently, the interest in biomass valorization and greener fuels has grown, and catalysts such as N -heterocyclic carbenes, calcium oxide, ZrO 2 /SO 4 , silicates and clays, , or aluminum chloride were (re)­discovered. Metal-based catalysis (such as Sn, Ti, or Mg , for instance) draws particular attention as zinc-based catalysts were recently used in the first reported vitrimer .…”