Metal-Free Phosphate Modified Hierarchically Porous Carbon–Silica Nanocomposites for Solvent-Free Glycerol Carbonylation and Esterification Reactions

Abstract

Mesostructured carbon−silica nanocomposites with hexagonally ordered pore channels have been synthesized from sucrose as a sustainable carbon source via a rotary evaporation induced self-assembly (REISA) method. Phosphate functionalization was performed on the resultant nanocomposite to obtain a strong acid catalyst with bimodal pores. The synthesized materials were thoroughly characterized by X-ray diffraction (XRD); Fourier transform infrared spectroscopy (FTIR); N 2 physisorption; field emission scanning electron microscopy (FESEM); acid titration; energy-dispersive X-ray (EDX) mapping; high-resolution transmission electron microscopy (HRTEM); X-ray photoelectron spectroscopy (XPS); 13 C, 29 Si, and 31 P solid-state magic angle spinning nuclear magnetic resonance (MAS NMR); and thermogravimetric analysis (TGA) techniques. The well-ordered mesopores facilitate the entrance and fast transport of molecules during reaction. The catalytic efficiency of the materials was tested for solventless glycerol carbonylation with urea and glycerol esterification involving acetic acid. The efficient catalytic performance could be associated to the higher acidity and better communicating hierarchically organized porous channels. The catalyst showed good reusability for both the reactions without any significant leaching. Therefore, the specified methodology here provides a useful pathway for the eco-friendly and effective preparation of hierarchically mesoporous carbon−silica composites and alteration of their physicochemical properties. This study opens new avenues for the development of sustainable, robust materials in rapid and facile conversion of biorenewable glycerol to fine chemicals.

Nest-Type ZNC⊂PtZnδ/C as a Highly Efficient Catalyst for Methanol Electro-Oxidation

“…The leaching resistance in 4 M sulfuric acid at 353 K, more harsh than the working conditions of DMFCs, is tested for catalysts of ZNC⊂PtZn δ /C and Pt 1 Zn 1 /C, and the results show that only ∼23.9 wt % Zn and ∼0.4 wt % Pt in ZNC⊂PtZn δ /C but ∼72.3 wt % Zn and ∼5.6 wt % Pt in Pt 1 Zn 1 /C were dissolved after 60 h, respectively. The dissolved Zn 2+ from ZNC⊂PtZn δ /C may be due to the destruction of Zn-N x coordination in the peripheral frameworks by the high concentration of sulfuric acid (Figure S14), which show more advantages in stability compared with the uncovered transition and noble metal alloy catalysts. , Therefore, ZNC⊂PtZn δ /C may be a practical catalyst to promote the development of DMFCs and even for green energy conversion. − …”

Bifunctional molybdenum phosphate catalyst with tunable acidity–basicity for the sustainable synthesis of glycerol carbonate via solvent‐free carbonylation of glycerol with urea

“…After the reaction ceased, methanol was added to it, and the reaction mixture was analyzed as mentioned in the earlier reports. [ 9,10 ]…”

“…After the reaction ceased, methanol was added to it, and the reaction mixture was analyzed as mentioned in the earlier reports. [9,10] 3 | RESULT AND DISCUSSIONS Figure 1b shows FTIR spectra of the catalysts. The broad band at 3390 cm À1 is due to O H stretching vibration, while the sharp band at 1630 cm À1 is due to O H bending vibration.…”

“…[7] Glycerol conversion can be achieved via several routes. [8][9][10] Glycerol carbonate is among the utmost significant chemicals within the family of glycerol derivatives. Its versatility lies within its physicochemical properties.…”

Metal‐Free Carbonaceous Catalytic Materials: Biomass Feedstocks for a Greener Future

“…Recently, phosphorus‐doped carbonaceous samples have also been reported as efficient metal‐free catalysts [52–56] . The main advantage of P dopants lies in the lower electronegativity of phosphorus atoms with respect to carbon (2.19 vs. 2.55, respectively) which could increase the electron donation capability.…”