Glycerol Carbonate Yield Research Articles

Metal-organic framework-derived base catalyst for conversion of dimethyl carbonate to glycerol carbonate

Glycerol carbonate (GLC) offers a range of benefits including biodegradability, versatility, and its potential for carbon capture and utilization. Base catalysts play a crucial role for GLC synthesis by facilitating the activation of reactants, enhancing nucleophilicity, accelerating reaction kinetics, and enabling catalyst regeneration. In this study, metal–organic framework (MOF) derived hybrid structure, CaO-MgO@Al2O3, was developed as a base catalyst to promote transesterification of glycerol with dimethyl carbonate (DMC) to form GLC. The results show that hydrothermal plus wet-impregnation routes formed the hybrid nanostructure with homogenously dispersed Ca, Mg and Al elements. Further, the synthesized catalysts showed significantly high specific surface area and basicity (2.656 mmol g−1). High selectivity (>99 %) and high GLC yield (96.2 %; 208.9 mmol g-cat−1) were achievable. This study demonstrated the rational design concept of MOF-derived hybrid structures used in the enhancement of base catalysis for transesterification of DMC to GLC, offering an effective solution with mild reaction conditions and high conversion.

Resourcification of CO2 to high-value-added glycerol carbonate by ZnAlCe composite oxides with frustrated Lewis pairs

Zinc-aluminum-cerium composite oxide (ZnAlCe) catalysts were prepared by co-precipitation to catalyze the direct synthesis of glycerol carbonate (GC) from carbon dioxide (CO2) and glycerol. The characterization results showed that the lattice oxygen served as Lewis basic centers and Ce4+ served as Lewis acidic centers on Zn4AlCe catalyst, and frustrated Lewis pairs (FLPs) were formed due to the steric hindrance in the catalyst structure. CO2 was easily activated by FLPs because the acidic and basic centers of FLPs bound to the oxygen and carbon atoms of CO2, respectively. The experimental results indicated that Zn4AlCe catalyst presented excellent catalytic performance with good thermal stability and strong regeneration ability. Under the reaction conditions of 0.115 g catalyst, 12 h, 170 °C, 4.5 MPaCO2 and 5 mL acetonitrile dosage, the GC yield and selectivity were 28.9 % and 51.0 %, respectively. The GC yield is relatively high among similar catalysts reported so far, which lays the foundation for future industrial considerations.

Active-site engineering of a frustrated-Lewis-pair Au-loaded Zn-Al catalyst for the highly stable synthesis of glycerol carbonate from co-utilisation of CO2 and glycerol

Solid frustrated-Lewis-pair catalysts, based on Zn-Al composite oxide modified loaded with Au (Aux/ZnAl-CHT), were prepared by calcination of hydrotalcite precursors and tested for the direct synthesis of glycerol carbonate using CO2 as the carbon source. An Au5/ZnAl-CHT catalyst shows the highest catalytic performance with the glycerol carbonate yield of 19.5 % and the selectivity of 50.5 % at 170 °C and 4.0 MPa CO2, while maintaining good thermal stability and excellent regeneration ability. A series of characterization results and density functional theory (DFT) calculations indicated the introduction of Au leads to more frustrated-Lewis-pairs in Zn-Al composite oxide (ZnAl-CHT), which improve the adsorption and activation of CO2. Meanwhile, FTIR analysis indicates that glycerol is activated by Zn2+ for the formation of zinc glycerolate intermediates. The above dual synergistic activation processes effectively enhance the catalytic performance. And the reaction pathway is proposed for the synthesis of glycerol carbonate from CO2 and glycerol.

Construction of DBU–based Poly (ionic liquid)s for the Conversion of CO2, Glycerol, and Propylene Oxide into Glycerol Carbonate

AbstractThe development of efficient heterogeneous catalysts for upgrading CO2, a greenhouse gas, and glycerol (Gly), an untapped biomass resource, into glycerol carbonate (GC) remains a challenge. Herein, 1,8‐diazabicyclo[5.4.0] undec–7–ene (DBU)–based poly (ionic liquid)s (PILs) were constructed for the one–pot synthesis of GC from CO2, Gly, and propylene oxide. Among them, P−DVB−DBUVBI–1 exhibited the best catalytic performance, achieving a GC yield of 90 % under optimal reaction conditions (100 °C, 6 h). The PIL catalyst was easily recovered and reused, as demonstrated by stable activity over five cycles. Density functional theory calculations showed that owing the strong positive charge delocalization ability of DBU onium, DBU–based PILs exhibit high nucleophilicity, which is the key to their efficient catalytic performance in the one–pot reaction.

Structural study of mixed metal oxide catalysts comprising Mg, Ca, and Al used for upgrading biodiesel byproduct glycerol to glycerol carbonate

Glycerol is a by-product in biodiesel production. It is possible to convert glycerol to glycerol carbonate by carbonylation with CO2. In this work, novel mixed metal oxides of Mg-Ca, Mg-Al, and Ca-Al were prepared by co-precipitation method, and used as catalysts for this reaction for the first time. Catalysts were characterized through XRD, BET surface area analyzer, XPS, ICP-OES, SEM, and CO2-TPD analyses. Mg0.75Ca0.25O catalyst showed the highest glycerol conversion of 18.2±0.7%, and glycerol carbonate yield of 12% at initial conditions. Reaction parameters including pressure, temperature, and catalyst loading were optimized, when Mg0.75Ca0.25O catalyst was used, to achieve the highest glycerol carbonate yield. The optimal reaction parameters were pressure of 7 MPa, temperature of 180 ⁰C, and catalyst loading of 8.5%. Glycerol conversion was 25.7% and the glycerol carbonate yield was 16% at optimized condition. Morphology and chemical structure of Mg-Ca catalyst were also investigated.

Reaction Kinetics and Mechanism for the Synthesis of Glycerol Carbonate from Glycerol and Urea Using ZnSO4 as a Catalyst

A series of Zn salts were used as catalysts for the reaction of glycerol and urea to produce glycerol carbonate and it was found that ZnSO4 showed the highest catalytic activity. Furthermore, the effects of reaction parameters on the glycerol conversion and glycerol carbonate yield were studied in detail. The results indicated that the glycerol conversion and glycerol carbonate yield were increased with the reaction temperature, reaction time, and catalyst amount while the optimal reaction conditions were 140 °C, 240 min, catalyst amount of 5 wt% (based on the glycerol weight), and urea-to-glycerol molar ratio of 1.1:1. During the reaction, the ZnSO4 catalyst is transformed into Zn(NH3)2SO4 at the initial stage of the reaction and then further transformed into Zn(C3H6O3). Zn(C3H6O3) and (NH4)2SO4 may be the true active species for the activation of urea and glycerol, respectively. The reaction mechanism is proposed in this article. Based on the experimental results, a reaction kinetics model considering the change in volume of the reaction system was also established, and the model parameters were obtained by fitting the experimental data. The statistical results showed that the established kinetics model is accurate.

Readily available, biocompatible sodium citrate catalyst for efficient glycerol carbonate production through transesterification of glycerol and ethylene carbonate

As a by-product in the biodiesel industry, surplus glycerol (Gly) has attracted considerable concern. The transesterification of Gly is one of the most promising reaction pathways to convert Gly to a value-added chemical such as glycerol carbonate (GC). Currently, development of catalysts for the transesterification with high activity is underway. Herein, a readily available biocompatible sodium citrate (Na3-citrate) catalyst was applied for efficient production of GC through transesterification of Gly and ethylene carbonate (EC). The effects of reaction parameters such as reaction time, EC to Gly molar ratio, reaction temperature, and catalyst loading on the reaction were investigated. Under optimal conditions, 0.01 wt% of Na3-citrate showed high catalytic activities with a Gly conversion of > 99 %, a GC yield of > 99 %, and a high turnover frequency of 16,925 gGC⋅g−1Cat⋅h−1. Furthermore, the reaction kinetic model for transesterification was established, and the activation energy of the Na3-citrate catalyzed transesterification was calculated as 51.3 kJ·mol−1. In addition, density functional theory calculations were used to unveil mechanism of the Na3-citrate catalyzed transesterification. It revealed that citrate anion of Na3-citrate could activate hydroxy of Gly via strong hydrogen bond interaction, thereby efficiently promoting transesterification by reducing energy barrier of rate-determining step.

Glycerol carbonate synthesis via transesterification of enriched glycerol and dimethyl carbonate using a Li-incorporated MCM-41 framework.

Waste crude glycerol was successfully enriched and utilized as an inexpensive source for producing value-added chemicals, such as glycerol carbonate (GC) - a valuable compound with extensive industrial applications. The Li/MCM-41 heterogeneous catalyst was synthesized and used for the transesterification of enriched glycerol and dimethyl carbonate (DMC) to produce GC. The catalyst's physicochemical properties were characterized using thermogravimetric, Hammett indicator, inductively coupled plasma-optical emission spectroscopy, nitrogen adsorption-desorption, X-ray diffractometry, scanning electron microscopy, and Fourier-transform infrared spectroscopy analyses. Reaction conditions were optimized using response surface methodology and analysis of variance, yielding an accurate quadratic model to predict the GC yield under different transesterification variables. The results revealed that 5%Li/MCM-41 served as the optimal catalyst, achieving the highest TOF of 4.72 h-1. The DMC: enriched glycerol molar ratio had the greatest impact on the GC yield, with an R2 = 0.9743 and adjusted R2 = 0.9502. The optimal GC yield (58.77%) with a final purity of 78% was attained at a 5.15 wt% catalyst loading relative to the initial amount of enriched glycerol, DMC: enriched glycerol molar ratio of 4.24 : 1, and a reaction temperature of 86 °C for 165 min. The 5%Li/MCM-41 heterogeneous catalyst could be reused for four cycles with a decreased GC yield from 58.77% to 45.72%. Thus, the Li/MCM-41 catalyst demonstrated a remarkable efficiency and potential as a heterogeneous catalyst for synthesizing GC. This method not only contributes to environmental sustainability by making use of a byproduct from biodiesel production but also aligns with the principles of a circular economy.

LTA zeolites as catalysts for transesterification of glycerol with dimethyl carbonate

The objective of this study was to investigate the use of LTA-structured zeolites as catalysts for synthesizing glycerol carbonate through the transesterification of glycerol with dimethyl carbonate, under mild reaction conditions. To evaluate the catalysts, a range of characterization techniques, including XRD, AES, SEM, TPD-NH3, TPD-CO2, and FT-IR with probe molecules like pyridine and pyrrole, along with elemental analysis, were employed. The investigation focused on various forms of LTA-structured zeolites (with K, Na, and Ca cations) to assess their impact on transesterification activity, with particular attention to the type of ion utilized and their basicity. Among these zeolites, K-Na-LTA (3A) zeolites demonstrated the most promising performance, achieving glycerol conversion rates ranging from 55 % to 77 %. Moreover, increasing basicity in the 3A zeolites led to higher glycerol conversion and glycerol carbonate yield. Encouragingly, all tested samples exhibited 100 % selectivity, exclusively producing the desired glycerol carbonate. However, during catalyst recycling, the decrease in glycerol conversion was observed, likely due to the leaching of active sites from the catalyst into the reaction medium. Methanol, being a one of the products, was identified as a potential agent responsible for the removal of potassium ions, during this process.

Production of glycerol carbonate from glycerol and carbon dioxide using metal oxide catalysts

This work is focused on a green production of glycerol carbonate through converting glycerol, as a by-product of biodiesel production, and a greenhouse gas, carbon dioxide, using metal oxide catalysts of MgO, CaO, and Al2O3. The catalysts were prepared by precipitation method and characterized by surface area and pore size, TGA, XRD, CO2-TPD, and SEM analyses. The catalysts’ performance was mostly influenced by the number of basic sites and the BET surface area of the catalysts. The catalysts’ activity results displayed that MgO showed the highest glycerol conversion of 22.7% and the highest yield of 10.6% among the investigated catalysts. The turnover number of the optimum catalyst was 14.9 μmol glycerol carbonate/μmol CO2. The effect of reaction parameters on the performance of the reaction was also investigated and the highest glycerol carbonate yield of 12.76 % was achieved at a catalyst loading of 5.5 wt% of glycerol amount, the temperature of 150 ⁰C, and pressure of 8 MPa. The physicochemical properties of catalysts were correlated with their activities and abilities for CO2 activation.

Synthesis and Optimization of Glycerol Carbonate from Crude Glycerol Using Sodium Carbonate (Na2CO3) as a Heterogeneous Catalyst.

The essential need for sustainable energy sources to replace fossil fuels has fueled interest in renewable energy and biorefinery processes. Biodiesel production generates a considerable amount of crude glycerol (CG), which poses a challenge for the industry. This study aims to address this challenge by purifying CG through acidification. The acidification process successfully purified crude glycerol (PCG), resulting in a purity of 98.4 wt %. Subsequently, synthesizing glycerol carbonate (GC) from PCG and dimethyl carbonate (DMC) was undertaken by using heterogeneous catalysts. Sodium carbonate (Na2CO3) emerges as the most promising catalyst, considering its suitability in the presence of impurities such as 0.72 wt % of water and 0.57 wt % of matter organic nonglycerol (MONG) in PCG. The optimum catalyst dosage of Na2CO3 was determined as 2.1% mol of PCG. The experiments were carried out using a central composite design (CCD) methodology. By employing the response surface method (RSM), the optimal reaction conditions were determined to be a PCG/DMC molar ratio of 1:2.37 and a reaction time of 1.83 h. Under these conditions, an observed GC yield of 72.13% and PCG conversion of 78.39% were achieved. Despite the purification process, PCG still contains residual water, making Na2CO3 a suitable catalyst capable of tolerating a water content up to 3 wt %. This study not only enhances the effective utilization of CG within the biodiesel industry but also offers valuable insights for further exploration of sustainable chemical processes in future research.

Transformation of glycerol and CO2 to glycerol carbonate over ionic liquids-composite catalysts: Activity, stability, and effect of Li/Al metal oxide

The direct conversion of glycerol and carbon dioxide (CO2) into glycerol carbonate (GC) provides a green pathway for utilizing both the waste glycerol and CO2. However, this reaction is hampered by low CO2 absorbency and H2O generation. Currently, high pressure and H2O trapping agents are employed to elucidate these problems. Our objective is to design a spongy metal oxide/ionic liquids (ILs) blended composite that can solve both limitations under moderate conditions. We created a glycol-modified biphasic cation with various anions aided ILs in combination with electrospin Li/Al nanofibers-500 (LANS-500). It achieved 98.40 % selectivity and 11.45 mmol g−1 cat., GC yield in 6 h at 4 MPa CO2 pressure, 140 °C, and 1.10 g catalyst. Furthermore, even after numerous recyclings, the catalyst yield or selectivity remain unaffected. Also, the LANS-500 catalyst has a porous nature which results in the formation of a strong “adduct” with CO2, as shown by Bode plot, FT-IR, and TGA analysis. ILs, conversely, are acidic, excellent thermal stability, low vapor pressure, and less viscosity. As a result, LANS-500 may be easily incorporated into ILs to produce a highly permeable network with high ratios of surface to volume to create a coordination structure that can absorb more CO2.

The Effect of Different Polyol Precursors on Disordered Spinel ZnAl2O4 Structure Prepared by the Polymeric Citrate Complex Method and the Corresponding Catalytic Behavior in the Glycerolysis of Urea

ZnAl2O4 is a cubic close‐packed oxide with tetrahedral and octahedral sites in the lattice structure. The catalytic activity of ZnAl2O4 is strongly connected with the surface properties caused by the partially inverse spinel ZnAl2O4 structure. In this research, ZnAl2O4 catalysts are prepared for the glycerolysis of urea via the polymeric citrate complex method using polymeric templates made of citric acid with a different polyol precursor. Depending on the polyol precursor, the partial inversion parameters representing the disordered bulk ZnAl2O4 structure are controlled, which results in different surface AlO4/AlO6 ratios and surface acidity. The specific surface areas of the prepared ZnAl2O4 catalysts are proportional to the molecular weight of the polyol precursor. The s–ZnAl2O4 (polyol precursor = sorbitol) prepared via two pathways from citrate complex and polymeric citrate complex shows the highest inversion parameter and surface acidity, leading to the highest glycerol carbonate (GC) yield and glycerol conversion in the glycerolysis of urea. A relationship between the GC yield and the surface properties, such as the acidity and inversion parameters, is established.

Layered double hydroxides modified by transition metals for sustainable glycerol valorization to glycerol carbonate

The surplus of glycerol generated as a by-product in biodiesel production increased interest in the investigation of the catalytic conversion of this platform molecule into valuable chemical products, such as glycerol carbonate. Therefore, the catalytic transesterification of glycerol and dimethyl carbonate for the synthesis of glycerol carbonate was studied using Cu-Zn-Mg-Al mixed oxide catalysts with different Cu-Zn atomic ratios. Layered double hydroxides were the precursors materials to obtain multi metallic oxides. They were synthesized by coprecipitation. The materials were physico-chemically characterized by XRD, MP-AES, N2 sorption, SEM, XPS and TPD-CO2. The addition of Cu and Zn to the Mg and Al matrix improved the catalytic behaviour of the solid materials. First, the highest glycerol carbonate yield was reached with the catalyst with the highest Zn load at 70 °C for 90 min. This result was taken as a basis to modify parameters and find the optimal reaction conditions. They were a temperature of 85 °C, a reaction time of 270 min, a DMC:glycerol molar ratio of 2:1, solvent free and 7.5 wt% of catalyst. The highest yield obtained (82%) was attributable to the synergistic effect of the Cu-Zn load promoted by an adequate distribution of basicity and textural properties. The reuses of the best catalyst were also investigated.

Synthesis of glycerol carbonate from industrial by-products by alcoholysis of urea: Crude glycerol and red gypsum

In this study, a heterogeneous catalyst was developed from red gypsum for the synthesis of glycerol carbonate through a glycerolysis reaction with urea. Under optimum reaction conditions, a simple heat treatment on bare red gypsum in a static air environment produces an 87% yield of the targeted glycerol carbonate product. The higher catalytic activity of the calcined catalyst is due to its basic characteristics and the presence of different phases of anhydrite CaSO4 with additional elements, especially an active hematite (Fe2O3) phase. The catalytic process was also found to be insensitive to the type of flowing gas that was used to remove the evolved ammonia gas, whereby, either inert nitrogen gas or reactive air containing oxygen did not significantly impact the glycerol carbonate yield. Indeed, with a promising yield, the developed catalytic system was able to directly synthesise glycerol carbonate from industrial crude glycerol from a biodiesel plant. The red gypsum-based catalytic system seems resistant to the presence of a certain level of moisture and other impurities in crude glycerol. The catalyst efficiency is being retained for consecutive reaction cycles, which are subsequently reused for the next batch reaction without requiring any pre-treatment.

A Green Approach to Obtaining Glycerol Carbonate by Urea Glycerolysis Using Carbon-Supported Metal Oxide Catalysts.

The results of sustainable and selective synthesis of glycerol carbonate (GC) from urea and glycerol under ambient pressure using carbon-fiber-supported metal oxide catalysts are reported. Carbon fibers (CF) were prepared via a catalytic chemical vapor deposition method (CCVD) using Ni as a catalyst and liquefied petroleum gas (LPG) as a cheap carbon source. Supported metal oxide catalysts were obtained by an incipient wetness impregnation technique using Zn, Ba, Cr, and Mg nitrates. Finally, the samples were pyrolyzed and oxidized in an air flow. The obtained catalysts (10%MexOy/CFox) were tested in the reaction of urea glycerolysis at 140 °C for 6 h under atmospheric pressure, using an equimolar ratio of reagents and an inert gas flow for NH3 removal. Under the applied conditions, all of the prepared catalysts increased the glycerol conversion and glycerol carbonate yield compared to the blank test, and the best catalytic performance was shown by the CFox-supported ZnO and MgO systems. Screening of the reaction conditions was carried out by applying ZnO/CFox as a catalyst and considering the effect of reaction temperature, molar ratio of reagents, and the mode of the inert gas flow through the reactor on the catalytic process. Finally, a maximum yield of GC of about 40%, together with a selectivity to glycerol carbonate of ~100%, was obtained within 6 h of reaction at 140 °C using a glycerol-to-urea molar ratio of 1:1 while flowing Ar through the reaction mixture. Furthermore, a positive heterogeneous catalytic effect of the CFox support on the process was noticed.

Enhanced Lewis basicity of ZIF-8 from metal incorporation (Mg, Cu, or Ce) for glycerol carboxylation using CO2 as a feedstock

Herein, Mg, Ce, and Cu were incorporated into ZIF-8 to improve its Lewis basicity for glycerol carboxylation. Upon metal incorporation, the Ce- and Cu-incorporated ZIF-8 remained structurally intact with slightly increased Lewis basicity, whereas the Mg-incorporated ZIF-8 exhibited a more perturbed structure containing additional exposed N atoms and metal sites (Zn and Mg). The improved Lewis basicity facilitated the increased glycerol conversion of the Mg-incorporated ZIF-8 and its yield of glycerol carbonate in the presence of CH3CN as a homogeneous dehydrating agent. Using NaHCO3 as the heterogeneous dehydrating agent, a much higher selectivity (90%) was obtained over Mg-incorporated ZIF-8 compared to that of CH3CN (∼60% higher), attributed to a high water sorption capability of NaHCO3 that inhibits side reactions. The heterogeneity of NaHCO3 enables efficient recycling (>3 cycles) for repeated catalytic glycerol carboxylation. The results suggested that metal incorporation is an effective and facile approach to improve ZIF-8 Lewis basicity, combined with heterogeneous NaHCO3 as the dehydrating agent, which is beneficial for glycerol carboxylation using CO2 as a feedstock.

The atom-efficient production of glycerol carbonate via transesterification between dimethyl carbonate and glycerol over fluorinated Al2O3-ZrO2 solid solution catalysts with suitable acidic-basic property

A series of Al2O3-ZrO2-nF solid solution catalysts (n was the F: Al atomic ratios) with Al: Zr molar ratio of 0.2, was fabricated by addition of varied amounts of (AlF6)3- into the ZrO2 via a co-precipitation method. To our delight, the acidic-basic properties of Al2O3-ZrO2-nF can be tuned by the change of n. Then, the role of acidic-basic sites was investigated for the glycerol carbonate (GLC) production from glycerol and dimethyl carbonate (DMC). Despite that the more basic samples exhibited higher reactivities compared to that of the more acidic ones, the cooperative effect between the acidic-basic pairs can enhance the catalyst activity strongly. So, the catalyst with F/Al= 1.0 can realize the quantitative and selective transformation of glycerol to GLC applying DMC/glycerol of 1:1 ratio with a GLC yield of 91.2%, owing to its appropriate acidic-basic property. Furthermore, the uniform solid solution structure can prevent the generation of free Al or F species, assuring the catalytic material an excellent stability. More importantly, several green parameters including process mass intensity, environmental factor and atom utilization were calculated to confirm the environmental and economic compatibility of the GLC synthesis over the model catalyst.

Effect of Calcination Temperatures on Surface Properties of Spinel ZnAl2O4 Prepared via the Polymeric Citrate Complex Method-Catalytic Performance in Glycerolysis of Urea.

In this study, we investigated urea glycerolysis over ZnAl2O4 catalysts that were prepared by using a citrate complex method and the influence of calcination temperatures on the surface properties of the prepared catalysts by varying the calcination temperature from 550 °C to 850 °C. As the reciprocal substitution between Al3+ and Zn2+ cations led to the formation of a disordered bulk ZnAl2O4 phase, different calcination temperatures strongly influenced the surface properties of the ZnAl2O4 catalysts, including oxygen vacancy. The increase in the calcination temperature from 550 °C to 650 °C decreased the inversion parameter of the ZnAl2O4 structure (from 0.365 to 0.222 for AlO4 and 0.409 to 0.358 for ZnO6). The disordered ZnAl2O4 structure led to a decrease in the surface acidity. The ZnAl2O4-550 catalyst had a large specific surface area, along with highly disordered surface sites, which increased surface acidity, resulting in a stronger interaction of the Zn NCO complex on its surface and an improvement in catalytic performance. Fourier transform infrared and thermogravimetric analysis results of the spent catalysts demonstrated the formation of a greater amount of a solid Zn NCO complex over ZnAl2O4-550 than ZnAl2O4-650. Consequently, the ZnAl2O4-550 catalyst outperformed the ZnAl2O4-650 catalyst in terms of glycerol conversion (72%), glycerol carbonate yield (33%), and byproduct formation.

Unveiling the complementary mechanism in the one-pot synthesis of glycerol carbonate from CO2 and glycerol

The chemical conversion of inert carbon dioxide (CO2) into high value-added chemicals is a continuing challenge. In this work, an experimental and theoretical mechanism study is presented for one-pot synthesis of glycerol carbonate (GC) from CO2, glycerol (Gly), and propylene epoxide (PO) catalyzed by 1,8-diazabicyclo[5.4.0]undec-7-enenium iodide (HDBUI) ionic liquid. 92% GC yield was obtained in the one-pot reaction through cycloaddition of CO2 with PO to produce propylene carbonate (PC), followed by transesterification of Gly with PC to yield targeted products. Density functional theory (DFT) calculations were used to unveil the HDBUI-mediated catalytic mechanism and key catalytic species. It was revealed that the HDBUI-catalyzed cycloaddition was assisted by the hydrogen bond donor Gly, the transesterification reactant, by promoting the ring-opening of PO and the insertion of CO2. By activating Gly hydroxyl group, alkaline HDBUI-bonded propan-1-ylium-2-yl carbonate, an intermediate in cycloaddition, catalyzed transesterification. The complementary mechanism of cycloaddition and transesterification in the one-pot provides a feasible method for utilizing inert CO2.