Tandem Synthesis of Glycidol via Transesterification of Glycerol with DMC over Ba-Mixed Metal Oxide Catalysts

Abstract

Glycerol carbonate (GC) and glycidol (GD) are commercial products possible from glycerol transformation, which has become a subject of great importance. Among several basic catalysts screened in this work, BaO showed the highest glycerol conversion of 71% with almost complete selectivity to GC. A tandem synthesis of GD with a selectivity as high as 80% with 98% glycerol conversion could be achieved with mixed oxides of Ba and lanthanides (La and Ce) prepared by the coprecipitation method. Although BaO alone showed the highest basicity as measured by CO 2 TPD, tuning of basicity by incorporation of CeO 2 resulted in the formation of GD. Incorporation of Ba into the ceria matrix induced oxygen vacancies in the cerium oxide material. The presence of u″/v″ doublets at 888.7 and 903.2 eV, respectively, in XPS of the Ba−Ce sample also confirmed the oxygen vacancies in the lattice. In this tandem approach to GD, the subsequent decarboxylation of initially formed GC was due to the presence of a CeO 2 lattice with defects, which is known to be the best for CO 2 adsorption. Increase in both catalyst loading and temperature showed a dramatic enhancement in GD selectivity. A plausible reaction pathway for the transesterification of glycerol with DMC to give GC followed by its decarboxylation to GD is also proposed based on the structural characterization and activity studies.

First Attempt of Glycidol‐to‐Monoalkyl Glyceryl Ethers Conversion by Acid Heterogeneous Catalysis: Synthesis and Simplified Sustainability Assessment

“…[8,[14][15][16] Furthermore,g lycidol is a very reactive molecule employeda lso for the production of severalinteresting compounds (diols, organic carbonates, pharmaceuticals, polymers, etc.) [25,26] In this work, we show for the first time the selectivepreparation of MAGEsf rom glycidol and severala lcohols by using acid heterogeneous catalysts under very mild reaction conditions (80 8C, 3h,0 .5 mol %c atalyst). [17][18][19][20] Nowadays, the worldwide glycidol market is based on the fossil-based route that involves the oxidation of allyl alcohol, obtained in turn from propylene, promoted by titanium silicate (TS-1) catalysti nt he presence of H 2 O 2 with ac onversiono f 47 %a nd as electivity of 92.5 %t owardg lycidol.…”

“…More recently, new synthetic processes (glycerol carbonated ecomposition and glycerolt ransesterification with dimethylcarbonate catalyzed by mixed oxides, mainly Ba and lanthanides) have been proposed, but they seem to be, at the moment,n ot economically and environmentally viable. [25,26] In this work, we show for the first time the selectivepreparation of MAGEsf rom glycidol and severala lcohols by using acid heterogeneous catalysts under very mild reaction conditions (80 8C, 3h,0 .5 mol %c atalyst). Acid catalysts show high stability under the investigated reaction conditions and ag ood ability to activate the oxirane ring of glycidolt ot he nucleophilic attack of alcohol.…”

Polymers Based on Cyclic Carbonates as Trait d'Union Between Polymer Chemistry and Sustainable CO2 Utilization

“…[56] The transesterification of glycerolw ith DMC by using basic mixed metal oxide catalysts is gaining increasing relevance from the standpoint of sustainability( Scheme 4, route a). [59] By using suitableh eterogeneous catalytic systems, [60,61] GD can be obtainedw ith good selectivity (about 80 %) over GC for quantitative glycerol conversion. [59] By using suitableh eterogeneous catalytic systems, [60,61] GD can be obtainedw ith good selectivity (about 80 %) over GC for quantitative glycerol conversion.…”

“…[57,58] Partiald ecarboxylation of GC may lead to GD as byproduct of the transes-terification process (Scheme 4). [59] By using suitableh eterogeneous catalytic systems, [60,61] GD can be obtainedw ith good selectivity (about 80 %) over GC for quantitative glycerol conversion. An alternative route for the preparation of GD is offered by the deoxydehydration (DODH) of glycerol, followed by epoxidation of the allylic alcoholp roduct (Scheme 4, route b).…”

Carbonylation of glycerol with urea to glycerol carbonate over supported Zn catalysts

“…However, there is no evidence that a direct CO 2 insertion occurred and glycerol carbonate was only produced when another organic carbonate was added as a reactant. The most widely studied route of GC synthesis is the transesterification of glycerol with dimethyl carbonate (DMC) [15,16], ethylene carbonate (EC) [17,18] and propylene carbonate (PC) [19]. However, these cyclic carbonates used for transesterification are typically synthesized either from phosgene utilization or energy intensive route involving epoxide.…”