Carbonylation Of Glycerol Research Articles

Harnessing Mg–Zn–Ce Ternary Mixed Oxide Nanostructure-Based Catalysts for Efficient Carbonylation of Glycerol with CO2 to Glycerol Carbonate

Harnessing Mg–Zn–Ce Ternary Mixed Oxide Nanostructure-Based Catalysts for Efficient Carbonylation of Glycerol with CO₂ to Glycerol Carbonate

Highly dispersed MgInCe-mixed metal oxides catalyzed direct carbonylation of glycerol and CO2 into glycerol carbonate

Glycerol carbonate, an important glycerol value-added product, has been widely used as the active intermediates and inert solvents in the synthesis of cosmetics, detergents, chemical intermediates, polymers, and so on. The direct carbonylation from glycerol with CO2 is considered as a promising route, but still a tough work due to the thermodynamic stability and the kinetic inertness of CO2. In this work, highly-selective direct carbonylation of glycerol and CO2 into glycerol carbonate has been achieved over highly dispersed MgInCe-mixed metal oxides (MgInCe-MMO), which were prepared through the topological transformation derived from the MgInCe-layered double hydroxides (MgInCe-LDHs). By precisely modulating the surface basic-acidic properties and the oxygen vacancies, an efficient carbonylation of glycerol with CO2 has been achieved with a selectivity of up to > 99% to glycerol carbonate. Deep investigation on the synergistic catalysis of base-acid sites and oxygen vacancies has been clarified.

The Synthesis of Glycerol Carbonate from Glycerol and Carbon Dioxide over Supported CuO-Based Nanoparticle Catalyst.

A series of supported CuO-based nanoparticle catalysts were prepared by the impregnation method and used for the synthesis of glycerol carbonate from glycerol and CO2 in the presence of 2-cyanopyridine as a dehydrant and DMF as a solvent. The effects of supports (activated alumina, silicon dioxide, graphene oxide, graphene, and activated carbon), CuO loading amount, calcination temperature, and reaction parameters on the catalytic activity of the catalyst were investigated in detail. XRD, FTIR, SEM, BET, and CO2-TPD were used for the characterization of the prepared catalysts. It is found that CuO/Al2O3 shows a higher catalytic activity, which depends on the CuO loading amount and calcination temperature. The surface area and number of basic sites of the catalyst exhibit a crucial effect on the catalytic activity of CuO/Al2O3. Furthermore, there is a synergistic effect between the catalyst and 2-cyanopyridine where the former has a higher activation ability for glycerol and the latter acts not only as a dehydrant, but also as a promoter for CO2 activation. Recycling experiments reveal that this catalyst can be reused for at least five cycles without any inactivation. Based on the experiment results and FTIR characterization, a possible reaction mechanism for the carbonylation of glycerol and CO2 is proposed.

N-doped porous carbon-anchored zinc single-atom as an efficient and robust heterogeneous catalyst for glycerol carbonylation with urea

Constructing highly efficient and stable heterogeneous catalysts for glycerol carbonylation is a very significant subject for its importance in promoting the development of biodiesel industry. Herein, a carbon-based single-Zn-atom catalyst (Zn1/NC) was prepared by using N-doped porous carbon material (NC) as support via a wet impregnation technique, following a thermal treatment at 600 °C. Various characterization results demonstrate that Zn2+ cations are atomically dispersed on the surface of NC support by coordination with the existed N- and O-containing groups. The Zn1/NC catalyst exhibited outstanding catalytic activity, selectivity and stability for glycerol carbonylation with urea at mild conditions. Operando ReactIR spectra results show that urea molecules could be easily activated by the single-atom Zn catalyst then react with glycerol molecules to generate the main product of glycerol carbonate via an intermediate of 2,3-dihydroxypropyl carbamate. Density functional theory calculations reveal that NC support could provide a unique coordination environments for the single-atom site of Zn2+, which can guarantee the preferential adsorption of urea molecule (rather than glycerol) and effectively inhibit the generation of the unfavorable Zn-glycerol complex, thus leading to the formation of highly efficient and robust heterogeneous catalyst for glycerol carbonylation with urea.

Porous carbon supported Lewis acid-base sites as metal-free catalysts for the carbonylation of glycerol with urea

Glycerol carbonylation is one of the most efficient reaction pathways to utilize glycerol, one of the by-products in biodiesel industry. So far, the vast majority of the reported glycerol carbonylation catalysts contain metals, which are not environmentally friendly. The recent emerging Lewis acid-base chemistry had provided powerful alternatives for metal-free catalysis. Here, we report the facile preparation of the B,N,P co-doped porous carbon materials, and the Lewis acidic/basic defects were detected in their structures. The obtained material BNP@C-800 exhibits excellent catalytic performance for the catalytic carbonylation of glycerol with urea, which achieved up to 93.6% glycerol conversion and 93.7% glycerol carbonate selectivity under metal-free conditions. The catalyst BNP@C-800 could be easily recycled for five times only by simple treatments without obvious loss in catalytic activity. In addition, the key reaction intermediate glycerol urethane was successfully characterized via React-IR spectroscopy. Furthermore, a heterogeneous Lewis acid-base synergistic catalysis mechanism is proposed.

Activity performance and kinetics for glycerol carbonylation with urea over Zn‐Co mixed metal oxide catalyst

AbstractEfficient carbonylation of glycerol using urea with Zn‐Co mixed metal oxide (MMO) catalyst has been achieved. Various methods of catalyst preparation were explored for glycerol carbonate (GC) synthesis. The optimized method of catalyst preparation was found to be co‐precipitation (CP) with a Zn:Co ratio of 70:30, achieving 81% glycerol conversion with 97% GC selectivity. X‐ray diffraction (XRD) studies revealed the formation of ZnO, Co3 O4, and spinel ZnCo2O4 phases. Thermal treatment given to the catalyst allows insertion of Zn cations into Co3O4 lattice forming ZnCo2O4 phase which was also evidenced in X‐ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Herein, for the first time, reaction kinetics was studied to propose the rate equation, based on which a plausible reaction pathway is proposed involving two‐site adsorption of glycerol (basic site) and urea (acidic site), which undergo carbonylation followed by cyclization into GC. A recycle study and hot filtration test have proven the reusability of the catalyst.

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

Tuning the surface acidity–basicity via molecular level control of the chemical composition of the catalyst is one of the thrust areas of research. Herein, we first report a bifunctional molybdenum phosphate catalyst with tunable acidity–basicity for the sustainable synthesis of glycerol carbonate involving glycerol and urea. The catalyst has been thoroughly characterized by using powder X‐ray diffraction, Fourier‐transform infrared, X‐ray photoelectron spectroscopy, N2 physisorption, field emission scanning electron microscopy, transmission electron microscopy, temperature programmed desorption (TPD), Py‐IR, 31P nuclear magnetic resonance and thermogravimetric analysis. It has been observed that the physicochemical properties of the catalysts changed considerably by varying the metal and phosphorus concentrations. The molybdenum phosphate catalyst with Mo/P molar ratio = 1:3 was found most active, having the highest acidity to basicity ratio. Interestingly, the reason could be associated to the presence of higher Brønsted acidity, as evidenced from the TPD and Py‐IR results. The physicochemical properties of the used catalyst suggest it as a stable and reusable catalyst. A study on operating parameters was carried out to optimize catalytic performance to obtain glycerol conversion up to 95% at a glycerol carbonate selectivity of 99%. This remarkable catalytic performance could be attributed to the bifunctional nature of the catalyst.

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

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

Mingled Metal Oxides Catalyst for Direct Carbonylation of Glycerol into Glycerol Carbonate

AbstractThe escalation of CO2 into the atmosphere has encouraged the development of sustainable pathways to produce materials and chemicals from CO2. In the present manuscript, an attempt has been made for direct carbonylation of glycerol into Glycerol carbonate (GC) by using CO2 over mingled metal oxide (MMO) catalyst. Several single, bi and trimetal oxides catalysts were explored for direct carbonylation of glycerol. Among the tested catalysts, Cu incorporated MMO showed the profound effect to obtain maximum glycerol conversion and GC selectively. However, a series of MMO catalysts with variable Cu loading were synthesized by simple co‐precipitation method and tested for direct carbonylation of glycerol. Of all tested Cu loaded MMO catalyst, 5 % Cu loaded MMO catalyst (CuO/CeO2/ZnO) showed highest GC selectivity (99 %). Furthermore, the process intensification study was conducted to investigate the influence of various reaction parameters on glycerol conversion and GC yield such as catalyst loading, temperature, CO2 pressure, time, and solvent concentration. The intensified process resulted into 57.4 % glycerol conversion with 57.2 % GC yield and 99.65 % selectivity. Moreover, the in‐depth physicochemical characterisations of the synthesised MMO catalyst were conducted by using various surface analytical techniques. The synthesised MMO has showed a synergistic and protagonistic effect for direct carbonylation of glycerol. The recyclability study was performed to examine the robustness and efficency of the MMO catalyst that showed the consistency in the GC yield, conversion and selectivity without any significant loss after six consecutive runs. Also, the plausible reaction mechanism over MMO catalyst was proposed. The reported methodology has explored a simple, robust and efficient process for direct carbonylation of glycerol by using MMO catalyst with higher yield and selectivity of GC.

Porous Carbon Supported Solid State Frustrated Lewis Pairs as Metal-Free Catalysts for the Carbonylation of Glycerol with Urea

Porous Carbon Supported Solid State Frustrated Lewis Pairs as Metal-Free Catalysts for the Carbonylation of Glycerol with Urea

Soft-templating routes for the synthesis of mesoporous tantalum phosphates and their catalytic activity in glycerol dehydration and carbonylation reactions

The craftsmanship in catalyst synthesis becomes very fascinating when the catalytic activity of the material can be enhanced by tuning the synthesis conditions. The underlying fundamental strategy is presented here in tailoring the structural and chemical behavior of the tantalum phosphates (TaP) by using different structure directing agents (SDAs). We found that by employing appropriate template assisted pathway it is possible to tune the morphology and the nature of active sites of TaP. The synthesised catalysts were comprehensively characterised by N2-physisorption, FESEM, HRTEM, powder XRD, FTIR, UV–Vis, XPS, NH3 and CO2-TPD, Py-adsorbed IR, elemental analysis and 31P{1H} NMR techniques. The FESEM and HRTEM analysis revealed the transition of non-spherical to rod-shaped particles upon moving from ionic to non-ionic surfactants. The TPD and Py-IR studies revealed the variation in amount, strength and nature of the acidic-basic sites with the change in SDA. The resultant TaP catalysts were investigated for gas phase glycerol dehydration to acrolein and liquid phase glycerol carbonylation to glycerol carbonate. Among these catalysts, TaPC synthesized by using CTAB as SDA exhibited promising catalytic activity in both gas and liquid phase reactions. The active site elucidation in TaPC catalyst was done by adopting basic probe molecule 2,6-lutidine. The deactivation kinetic study was carried out for the gas phase glycerol dehydration reaction. The investigation on the spent catalyst showed it is stable under both gas-phase and liquid-phase reaction conditions. This study hence provides a pathway for analytical architecture and construction of highly efficient TaP catalysts for glycerol transformation reactions.

In situ fabrication of layered double hydroxide film immobilizing gold nanoparticles in capillary microreactor for efficient catalytic carbonylation of glycerol

• Layered double hydroxides crystallite were in situ fabricated on inner wall of capillary. • Thickness and morphology of LDH film on inner-wall of capillary was finely controlled. • Au NPs were immobilized on layered double hydroxides film. • Au/LDH film showed good catalytic activity in carbonylation of glycerol with urea. • The productivity of glycerol carbonate reached 3.78 g•h −1 •g −1 on Au/LDH catalytic film. Microreactor is capable of intensifying catalytic reaction processes. The fabricating of catalytic film inside microchannels for catalytic reaction remains a challenge. Here we report a facile method for in situ fabrication of layered double hydroxide (LDH) film immobilizing gold nanoparticles in capillary microreactor. Through adjusting the reaction condition of in situ hydrothermal crystallization process and flow deposition process inside microchannel, film thickness, film morphology and Au loading of Au/LDH coating can be finely controlled. Such Au/LDH film inside microchannel exhibited good performance in catalytic carbonylation of glycerol with urea. The yield of glycerol carbonate reached 31.9% at flow rate of 10 µl/min, residence time of 6.62 min and reaction temperature of 413 K under atmospheric pressure. The maximum productivity of 3.78 g∙h −1 ⋅g −1 was obtained at flow rate of 40 µl/min and residence time of 1.65 min under same reaction temperature and pressure. Continuously running the microreactor for 30 h proved the high stability of this catalytic film inside microchannels. This approach could be extended to fabricate other diatomic and triatomic metal LDH films immobilizing metal nanoparticles inside microchannels for heterogeneous catalysis.

Role of preparation parameters of Cu–Zn mixed oxide catalyst in solvent free glycerol carbonylation with urea

Solvent-free carbonylation of glycerol with urea to glycerol carbonate (GC) was achieved over heterogeneous Cu–Zn mixed oxide catalyst. Cu–Zn catalysts with different ratios of Cu:Zn were prepared using co-precipitation (CP) and oxalate gel (OG) methods. As compared to CuO–ZnO(2:1) catalyst prepared by oxalate gel (OG) method, much higher conversion of glycerol and highest selectivity towards glycerol carbonate (GC) was achieved with CuO–ZnO_CP(2:1) catalyst. Physicochemical properties of prepared catalysts were investigated by using XRD, FT-IR, BET, TPD of CO2 and NH3 and TEM techniques. The effect of stoichiometric ratio of Cu/Zn, calcination temperature of CuO–ZnO catalysts and effect of reaction parameters such as molar ratio of substrates, time and temperature on glycerol conversion to GC were critically studied. Cu/Zn of 2:1 ratio, glycerol–urea 1:1 molar ratio, 145 ​°C reaction temperatures were found to be optimized reaction conditions to achieve highest glycerol conversion of 86% and complete selectivity towards GC. The continuous expel of NH3 from reaction the mixture avoided formation of ammonia complex with CuO–ZnO catalyst. As a result of this, CuO–ZnO catalyst could be recycled up to three times without losing its initial activity.

Zn-Doped CeO2 Nanorods for Glycerol Carbonylation with CO2

The chemical industry is facing a major challenge in the design of heterogeneous catalysts for CO2 activation and valorization. The modification of CeO2 nanorods with divalent transition metal ions...

A highly efficient rod-like-CeO2-supported palladium catalyst for the oxidative carbonylation of glycerol to glycerol carbonate.

A rod-like-CeO2-supported Pd catalyst (Pd/CeO2-r) was prepared using two-step hydrothermal impregnation and used in the oxidative carbonylation of glycerol to produce glycerol carbonate. The characterization results showed that the Pd was highly dispersed on the surface of the CeO2-r, and metallic Pd was the main species in the catalyst. The Pd/CeO2-r exhibited good catalytic performance for the oxidative carbonylation of glycerol. Under optimized reaction conditions, the glycerol conversion and glycerol carbonate selectivity were 93% and 98%, respectively, and turnover frequency was 1240 h−1. However, because of the leaching of Pd and the growth of Pd particles, the catalyst was gradually deactivated throughout reuse.

Palladium coordinated in N-heterocyclic carbene-functionalized porous organic polymer for efficient oxidative carbonylation of glycerol

Palladium coordinated in N-heterocyclic carbene-functionalized porous organic polymer (Pd@PQP-NHC) was successfully prepared via a facile copolymerization and successive immobilization method. The obtained Pd@PQP-NHC that featured relatively large surface area, hierarchical pore structure, and strong electron interaction between Pd species and bis-NHC ligand, displayed very high catalytic activity for the oxidative carbonylation of glycerol. A 0.025 mol% of Pd loading was sufficient for 96% conversion of glycerol with a high turnover frequency (TOF) of 1901 h−1. Moreover, the catalyst could be reused at least nine consecutive recycles without obvious loss of its initial activity.

Disordered structure of ZnAl2O4 phase and the formation of a Zn NCO complex in ZnAl mixed oxide catalysts for glycerol carbonylation with urea

The effect of a disordered ZnAl2O4 spinel structure on glycerol carbonylation with urea was investigated with pure ZnAl2O4 (c-ZnAl2O4) and ZnAl mixed oxide (c-ZnAlO) prepared by a citrate complex method, and ZnAl physically-mixed oxide (p-ZnAlO). During catalysts preparation, a disordered bulk ZnAl2O4 phase generated disordered sites on the surface: the Al3+ cations substituting for Zn2+ cations at the tetrahedral sites, and the surface oxygen vacancy corresponding to the Zn2+ cations substituting for Al3+ cations at the octahedral sites. The disordered surface sites increased in order of p-ZnAlO < c-ZnAlO < c-ZnAl2O4, which was proportional to the surface acidity. c-ZnAlO exhibited the best reaction performance due to the existence of a solid zinc isocyanate (Zn NCO) complex on the disordered sites. Here, we proposed that the solid Zn NCO complex preferentially generated glycerol carbonate (GC), while the liquid Zn NCO complex produced both GC and zinc glycerolate.

Photo-thermal synergistically catalytic conversion of glycerol and carbon dioxide to glycerol carbonate over Au/ZnWO4-ZnO catalysts

Converting glycerol and CO2 into glycerol carbonate offers a green pathway for utilizing biodiesel by-product glycerol and greenhouse gas CO2 as well as synthesizing the important chemical compound glycerol carbonate. In this study, for the first time, the abundant visible light was introduced into thermal-driven glycerol carbonylation system, aiming to improve catalyst performance via breaking the thermodynamic equilibrium limitations. Here x%Au/ZnWO4-ZnO catalysts were designed for the photo-thermal catalytic system. It was found that, ZnWO4-ZnO itself was effective in glycerol carbonylation even under thermal-driven condition, and the loading of plasmonic Au further enhanced the catalytic performances especially with visible light irradiation. The visible light responsivity of the catalysts and reaction temperatures played important roles for the photo-thermal performance of x%Au/ZnWO4-ZnO, indicating the strong photo-thermal synergistic effect for the highly promoted catalytic performance. This study suggests the photo-thermal synergistic catalysis is one of efficient approaches for further improving catalytic performance.

Functionalized DVB-based polymer catalysts for glycerol and CO2 catalytic conversion

In the present work, several DVB-based polymer catalysts were prepared and used for the synthesis of glycerol carbonate (GC) from glycerol carbonylation with carbon dioxide (CO2). Propylene oxide (PO) was introduced as a coupling reagent into the reaction to disturb the thermodynamics limitation. The characterization results confirmed the successful preparation of the functionalized polymer catalysts. P-DVB-(vIm-BuBr) showed the best catalytic performance among the prepared polymers. The high catalytic activity of P-DVB-(vIm-BuBr) was attributed to the presence of ionic liquid groups in the structure of the polymer. In addition, the preparation method had a significant influence on the catalytic activity of the polymer. Functionalization of the monomer with n-butyl bromide before polymerization could increase the content of ionic liquid groups of the polymer catalysts. During the reaction process, glycerol served not only as a reactant, but also as a co-catalyst to facilitate the coupling of PO with CO2. P-DVB-(vIm-BuBr) achieved PO conversions as high as 96% and GC yields of 81% under optimal reaction conditions. The catalyst was highly recyclable and maintained its catalytic activity after five reaction cycles.

Transformation of CO2 with glycerol to glycerol carbonate by a novel ZnWO4-ZnO catalyst

ZnWO4-ZnO catalysts with different W content were prepared by conventional hydrothermal and wet impregnation methods and applied in the direct synthesis of glycerol carbonate from CO2 and glycerol. The crystallite structure, texture property, morphology, redox and acid-base properties and the surface chemical situation of the catalysts were characterized by XRD, BET, TEM, H2-TPR, NH3/CO2-TPD and XPS. The possible activation routes of CO2 and glycerol were analyzed with DRIFTS and FTIR. ZnWO4-ZnO composite catalysts showed better catalytic performances with respect to ZnO in the carbonylation of glycerol with CO2. The improved activity of ZnWO4-ZnO catalysts was associated with the formation of ZnWO4, the interaction between ZnWO4 and ZnO, and the enhanced moderate acidic property. DIRFTS results showed that chelating bidentate carbonate species was the main adsorption pattern for CO2 on ZnO, while the introduction of W led to the bridged bidentate carbonate, which became the main adsorption pattern on ZnWO4-ZnO. As for the activation of glycerol, zinc glycerolate played an important role in the reaction process. Based on the reaction and characterization results, a plausible reaction route involved a seven-membered ring esters intermediate was suggested for the reaction of CO2 and glycerol over ZnWO4-ZnO catalysts.