Propylene Carbonate Research Articles

Mesostructured Bifunctional ZnBr2/g‐C3N4 Catalysts Towards Efficient Cocatalyst‐Free Cycloaddition of CO2 to Propylene Carbonate

AbstractCatalytic cycloaddition of CO2 with propylene oxide (PO) is a sustainable pathway for the synthesis of propylene carbonate (PC), and the design of efficient heterogeneous catalysts is a hot research topic in both C1 chemistry and functional materials. In this work, graphitic carbon nitride (g‐C3N4) materials were prepared using urea (U) and melamine (M) as precursors through one‐step thermal condensation and then applied as catalyst supports for ZnBr2. As heterogeneous catalysts, the synthesized composites (ZnBr2/g‐C3N4‐MU) exhibited higher activity in the cycloaddition reaction of CO2 to PC than ZnBr2/g‐C3N4‐M and ZnBr2/g‐C3N4‐U. The preparation temperature of ZnBr2/g‐C3N4‐MU could affect the distributions of nitrogen species and acidic strength, which thus determined the final catalytic activity. More importantly, the loading of ZnBr2 not only introduced acidic sites but also enhanced the strength of alkaline sites of g‐C3N4‐MU, enabling ZnBr2/g‐C3N4‐MU materials as acid–base bifunctional catalysts in cycloaddition of CO2 with PO.

MnO2 as efficient and robust catalyst for halogen-free synthesis of cyclic carbonate from CO2 and epoxides

Cyclic carbonate is an important fine chemical/intermediate and their synthesis from CO2 and epoxides is economical and green pathway, however, it is still a challenge to develop a efficient and robust catalyst for halogen-free synthesis of cyclic carbonate. Herein, we successfully prepared large-scale MnO2 catalysts by microfluidics method, and the MnO2 especially δ-MnO2 showed >99.9 % propylene carbonate yield under 393 K, 3 MPa CO2 and DMF solvent. Moreover, the initial TOF value over δ-MnO2 on the basis of total catalyst amount was 5.80 h−1, which was the maximum among all the reported heterogeneous metallic oxide catalysts for halogen-free synthesis of propylene carbonate from CO2 and epoxides, and the superior catalytic performance can be ascribed to the abundant moderate acidic–basic active sites on the δ-MnO2 surface and the synergistic effect of δ-MnO2 and DMF. Furthermore, the δ-MnO2 can be reused at least 4 times and exhibited wide substrate applicability.

Molecular modeling and simulation of organic electrolyte solutions for lithium ion batteries.

Multi-criteria optimization is used for developing molecular models for ethylene carbonate (EC) and propylene carbonate (PC), organic solvents commonly used in Li-ion batteries. The molecular geometry and partial charges of the solvents are obtained from quantum mechanical calculations. Using a novel optimization strategy that combines systematic variations of the Lennard-Jones parameters with a reduced units approach, the models are fitted to experimental data on the liquid density, vapor pressure, relative permittivity, and self-diffusion coefficient. Since no experimental data for the self-diffusion coefficient of pure EC were available in the literature, they are measured in this work using a gradient-based nuclear magnetic resonance technique. For all pure component properties, excellent agreement between experiment and simulation is obtained. Moreover, the predictive capabilities of the new solvent models are assessed by comparison to experimental data for the liquid density and relative permittivity of mixtures of EC and PC. In addition, molecular models for the anions PF6-, BF4-, and ClO4- in solutions of their lithium electrolytes in PC are developed using experimental data on the solution densities. Finally, the self-diffusion coefficients of LiPF6 in PC and in aqueous solution are predicted and compared, showing that diffusion is much slower in the organic solution due to the formation of larger solvent shells around the ions. Furthermore, an analysis of the radial distribution functions in these solutions suggests that the ions have much less impact on the structure of the solvent PC than on water.

Insight into behaviors of internal interactions and thermodynamic properties of binary mixtures composed of ether-functionalized ionic liquids and 1,4-butyrolactone or propylene carbonate

A deeper comprehension of the mechanism behind various internal interactions and their influence on system properties encourages the utilization of ionic liquid mixture systems. In this work, the excess molar volume, viscosity deviation, change of electrical conductivity, and ionicity of both binary mixtures for N-methyl-N-methoxyethylpyrrolidinium bis(trifluoromethanesulfonyl)imide ([MOEMPYrr][TFSI]) ether-functionalized ionic liquids (ILs) with 1,4-butyrolactone (GBL) or propylene carbonate (PC) were systematically studied. The specific interactions between ILs and solvent molecules were investigated by using the COSMO-RS model in terms of DFT calculation. The results indicate that [MOEMPYrr]+ tends to act as a hydrogen bond donor and [TFSI]- tends to act as a hydrogen bond acceptor, and GBL (or PC) has a strong hydrogen bond acceptance ability. Furthermore, based on the radial distribution functions (RDFs) from molecular dynamics (MD) simulations, the H1 atom in [MOEMPYrr]+, the O2 atom in [TFSI]-, the O3 atom in GBL, and the O4 atom in PC are selected as reference sites to study the interaction between cations and anions (or solvent molecules). It is found that the interaction between anions and cations in the [MOEMPYrr][TFSI] + PC system is stronger than that in the [MOEMPYrr][TFSI] + GBL system, and the interaction between cations and GBL is stronger than that between cations and PC. This result further explains why the excess molar volumes (VE) of [MOMPYrr][TFSI] + GBL binary mixtures are greater than that of [MOMPYrr][TFSI] + PC binary mixtures from a microscopic perspective.

One-Pot Synthesis of Propylene Carbonate through Tandem Epoxidation-Cycloaddition Reaction from Propylene and CO2

One-Pot Synthesis of Propylene Carbonate through Tandem Epoxidation-Cycloaddition Reaction from Propylene and CO₂

Green co-solvent-assisted one-pot synthesis of high-performance flexible lignin polyurethane foam

Although lignin is a promising candidate as a source of polyol for producing eco-friendly polyurethane foam (PUF), its direct application has limitations, primarily stemming from the brittleness of the resulting products and poor processibility at high lignin loadings. To address these technical challenges, we introduced an effective co-solvent for the lignin-based polyurethane foams (LPUFs) with up to 80 wt% of lignin substitution for petroleum polyols. As a green co-solvent that involves carbon dioxide fixation during its production, propylene carbonate (PC), was blended with lignin and improved the distribution of lignin by decreasing the viscosity, providing a room-temperature reaction. The LPUFs demonstrated a comparable thermal insulation performance (R-values greater than 5 in−1) with commercially available PUF with a uniform size of closed-cell structure induced by the reduced viscosity of lignin-based polyol. LPUFs also showed enhanced fire retardancy and moisture resistance compared to the control PUFs, benefiting from lignin’s intrinsic fire-resistant and hydrophobic properties. To mitigate the brittleness issue at high lignin loadings, flexible polyethylene glycols (PEGs) with a high molecular weight (i.e., PEG-1000) were dissolved in PC at room temperature to further improve the mechanical strength of LPUFs. The compressive strength of LPUFs with 80 wt% lignin substitution content was remarkably improved to 226 kPa by the employment of co-solvent and PEG-1000 compared to the control PUF (<140 kPa). Moreover, the flexibility of the LPUFs was successfully controlled by simply adjusting the PEG-400/PEG-1000 ratio. The results of this study provide valuable insights for accelerating and broadening the utilization of lignin in sustainable materials and manufacturing areas.

Multifunctional Water Additive Enabling Stable Cycling of Chloride‐Free Magnesium Metal Batteries Based on Carbonate Electrolyte

AbstractRechargeable magnesium batteries (RMBs) face with the challenge of interphase passivation between electrolytes and Mg anodes. Compared with ether electrolytes, carbonate solvents possess the superior electrochemical stability at cathode side, but their incompatibility with Mg metal, high viscosity, and desolvation energy barrier restrict their practical utilization in RMBs. Herein, the “unwanted‐impurity” water with high concentration is revisited and employed as multifunctional additive in carbonate electrolyte to improve the reversibility of RMBs. Water additive enables the localized deep eutectic effect, reduces the viscosity of carbonate electrolyte, and improves the Mg ion conductivity. The water molecules also participate the solvation sheath of Mg ions, resulting in the reduction of Mg deposition overpotential and inhibition of parasitic reaction. Furthermore, the co‐intercalated water molecules in V2O5 cathode layers enable the stabilization of intercalation structure and supply of additional magnesiophilic sites. Cooperated with the binder‐decorated Mg powder anode, the propylene carbonate electrolyte with water additive endows Mg||Mg symmetric cells and Mg||V2O5 full cells with satisfactory cycling performance and high‐voltage stability. This work revisits the impact of impurity water and provides a practical strategy for the utilization of conventional low‐cost carbonate electrolyte family, broadening the design and formulation of electrolytes for chlorine‐free and high‐voltage RMBs.

Extraction of poly(3-hydroxybutirate) from Priestia megaterium using non-halogenated solvents: A comparative performance analysis

Solvent extraction using chloroform is the most common industrial process for poly(3-hydroxybutyrate) (P(3HB)) recovery from dried biomass, and still a major barrier to expanding the commercial application of this biodegradable biopolymer. Consequently, there is great interest in alternative non-halogenated solvents for this process and some relevant related results are available in the literature for P(3HB) recovery from Gram-negative bacteria. This work evaluated the potential of a set of non-halogenated solvents for the extraction of P(3HB) from Priestia megaterium, a Gram-positive bacterium of great potential for P(3HB) production. Ethyl acetate (EtAc), methyl ethyl ketone (MEK), dimethyl carbonate (DMC), dimethyl sulfoxide (DMSO), N,N-dimethylacetamide (NNDA), 2-heptanone (2-Hp), propylene carbonate (PC), and isoamyl propionate (IAP) were tested. Preliminary solubilization tests using commercial P(3HB) showed that EtAc, MEK, DMC and IAP had lower P(3HB) solubilization capacity (below 0.08 g/L for EtAc, MEK, and DMC; 1.3–2.5 g/L for IAP) than DMSO (65–70 g/L) and PC, 2-Hp and NNDA (>100 g/L). Then, only DMSO, PC, 2-Hp, and NNDA were evaluated in recovery tests with intracellular P(3HB). DMSO was not selective for P(3HB), causing digestion of cell wall components. PC, 2-Hp, and NNDA outperformed chloroform, but NNDA stood out for its remarkably higher recovery (98.5 %, 30 min, 140 ºC).

Enhancing the stability of sodium-ion capacitors by introducing glyoxylic-acetal based electrolyte

Sodium-ion Capacitors (SICs) are becoming increasingly important energy storage devices. This study presents an in-depth comparison of a largely used electrolyte for said application, sodium hexafluorophosphate in ethylene carbonate:propylene carbonate (NaPF6 in EC:PC), with the novel electrolyte sodium bis(trifluoromethanesulfonyl)imide in 1,1,2,2-tetraethoxyethane:propylene carbonate (NaTFSI in TEG:PC). Firstly, half-cells of the SIC standard electrode materials, hard carbon (HC) and activated carbon (AC), are shown to perform comparably well with the two electrolytes. However, the use of the novel electrolyte in SICs allows for an improved stability during float tests. All in all, the novel electrolyte NaTFSI in TEG:PC appears to be a very promising alternative electrolyte for SIC application.

Rational Optimization of Ammonium and Phosphonium Cations of Bifunctional Organoborane Catalysts for Copolymerization of Propylene Oxide with CO2 to Afford Poly(propylene carbonate)

Rational Optimization of Ammonium and Phosphonium Cations of Bifunctional Organoborane Catalysts for Copolymerization of Propylene Oxide with CO₂ to Afford Poly(propylene carbonate)

Combination of nanoparticles with single-metal sites synergistically boosts co-catalyzed formic acid dehydrogenation

The development of hydrogen technologies is at the heart of a green economy. As prerequisite for implementation of hydrogen storage, active and stable catalysts for (de)hydrogenation reactions are needed. So far, the use of precious metals associated with expensive costs dominates in this area. Herein, we present a new class of lower-cost Co-based catalysts (Co-SAs/NPs@NC) in which highly distributed single-metal sites are synergistically combined with small defined nanoparticles allowing efficient formic acid dehydrogenation. The optimal material with atomically dispersed CoN2C2 units and encapsulated 7-8 nm nanoparticles achieves an excellent gas yield of 1403.8 mL·g−1·h−1 using propylene carbonate as solvent, with no activity loss after 5 cycles, which is 15 times higher than that of the commercial Pd/C. In situ analytic experiments show that Co-SAs/NPs@NC enhances the adsorption and activation of the key intermediate monodentate HCOO*, thereby facilitating the following C-H bond breaking, compared to related single metal atom and nanoparticle catalysts. Theoretical calculations show that the integration of cobalt nanoparticles elevates the d-band center of the Co single atoms as the active center, which consequently enhances the coupling of the carbonyl O of the HCOO* intermediate to the Co centers, thereby lowering the energy barrier.

Volatile organic compound (VOC) emissions from no-added-formaldehyde lignosulphonate/pMDI particleboards and their effect on indoor air quality

ABSTRACT Wood-based panels, for example particleboards, are responsible for releasing formaldehyde and volatile organic compounds (VOCs), consequently polluting indoor air. Thus, the demand for eco-friendly wood adhesives, such as lignosulphonates (LS), has increased in detriment of the traditionally used urea-formaldehyde resins. However, combination with polymeric 4,4′-diphenylmethane diisocyanate (pMDI) is commonly proposed to minimize pressing times. In this study, particleboards were manufactured using a low lab-scale press factor of 7.5 s/mm. The adhesive contents were: 1.3% pMDI with 2.2% propylene carbonate (PC) solvent in the core layer and 15% LS in the surface layers. The VOC emissions of these boards were evaluated against those of commercial urea-formaldehyde boards. Headspace gas chromatography-mass spectrometry analysis indicated that the total VOC emissions were 66% higher for the LS/pMDI boards, comprising mainly of PC and furfural. After 14-days in a 25 L chamber, VOC emissions were examined according to ISO 16000-9:2006. LS/pMDI particleboards emitted four times more VOCs than standard boards, with 80% corresponding to PC and furfural, a suspected carcinogen. Consequently, the need for VOC quantification, even for bio-based boards is highlighted. An extension of EN 16516:2017 + A1:2020 to furniture products is also advised.

Fluorinated ester additive to regulate nucleation behavior and interfacial chemistry of room temperature sodium-sulfur batteries

Room temperature sodium-sulfur (RT Na-S) batteries are considered as advanced energy storage technology due to their low cost and high theoretical energy density. However, challenges such as the growth of sodium dendrite and dissolution of sodium polysulfides significantly hinder the electrochemical performance. Herein, we developed a propylene carbonate (PC)-based electrolyte with Methyl 2-Fluoroisobutyrate (MFB) as an additive. The ester group in the MFB additive is capable of participating in and reconfiguring the coordination of their Na+ solvated structures, thereby lowering the desolvation barrier and regulating the Na anode’s interfacial reaction and nucleation behavior. The polar C−F bond at the other end helps to reduce the lowest unoccupied molecular orbital (LUMO) energy of the MFB additive, enabling the preferential decomposition of MFB to form the F-rich inorganic phase strong polar solid electrolyte interphase (SEI), contributing to the inhibition of Na dendrite growth, the accumulation of dead Na. In addition, NaF-riched cathode electrolyte interphase (CEI) was also observed on sulfur-based cathode, which can effectively inhibited the shuttle effect. Consequently, the developed RT Na-S battery exhibit excellent electrochemical performance.

Dielectric and Shear-Mechanical "Humps" in the Nonlinear Response of Polar Glassformers.

Many glassformers display electrorheological effects and a pronounced maximum in their frequency dependent nonlinear dielectric response. The latter so-called "hump" feature was often linked to correlated-particle motions and, so far, was not explored in the large-perturbation mechanical response of viscous liquids. To first clarify the electro-viscoelastic coupling in the linear domain, using the modified Gemant, DiMarzio, and Bishop model, it is demonstrated how the small-amplitude shear mechanical response of S-methoxy-PC, a derivative of propylene carbonate, can be related to its complex dielectric permittivity. Then, in the nonlinear regime, a "hump" feature is identified in the rheological third-order shear modulus of S-methoxy-PC and of another polar glassformer, propylene glycol. Thus, the observation of a "hump" in the cubic response of viscous liquids does not necessarily rely on the application of electrical fields.

Colloidal dispersions of cobalt ferrite nanoparticles in EMIM TFSI, propylene carbonate and their mixtures

Liquid thermocells are promising devices for the recovery of low-grade waste heat and its conversion into electricity. The present study proposes dispersing charged magnetic nanoparticles in liquids to improve thermoelectric conversion, due to their thermodiffusive and magnetic properties. Core@shell cobalt ferrite@maghemite nanoparticles (NPs) of various sizes with three different kinds of coatings are tested for dispersion in EMIM TFSI (ethyl-methylimidazolium bistriflimide), an ionic liquid (IL) of high electrical conductivity. Among the tested ligands, PAC6MIM±Br− (1-(6-hexylphosphonate) 3-methyl imidazolium bromide) emerges as the most efficient due to its phosphonic group. This ligand leads to dispersions of clusters of a few dozen NPs in water and a few NPs in EMIM TFSI. For improving both the viscosity and the electrical conductivity, dispersions in binary mixtures of propylene carbonate (PC), a polar medium, and EMIM-TFSI are further investigated with the sample based on NPs of ∼ 9 nm diameter. Through a pumping and heating procedure, stable dispersions are obtained with a subsequent reduction of the size of the NP clusters, down to 1 to 2 NPs in EMIM TFSI and a few NPs in PC and their binary mixtures. The mixture with an IL mole fraction ∼0.2–0.3 and maximal electrical conductivity is a promising candidate for further thermoelectric investigations.

Highly Efficient Carbonylation of Propylene Oxide into β‐Butyrolactone Catalyzed over Co‐Al Bimetallic Species†

AbstractRational designation of the catalyst for efficient atom‐economic conversion of propylene oxide (PO) and carbon monoxide (CO) into β‐butyrolactone is of current significance. By employing the O,N,O‐tridentate ligands R1,R2LH2 (1–4), the aluminium compounds (R1,R2LAlCl)2 (R1,R2=H,H (5), tBu,tBu (6), Cl,Cl (7), Br,Br (8)) and the derived anion‐cation pairs [H,HLAl(THF)3]+[Co(CO)4]− (9) and [(R1,R2LAl)2Cl(THF)2]+[Co(CO)4]− (R1,R2=tBu,tBu (10), Cl,Cl (11), Br,Br (12)) as well as the aluminium‐cobalt bimetallic cluster compounds [(R1,R2LAl)2Cl(THF)][Co3(CO)10] (R1,R2=tBu,tBu (13), Cl,Cl (14), Br,Br (15)) were prepared. Compounds 9–12 efficiently catalyzed the PO carbonylation into β‐butyrolactone to achieve up 93.4–98.9 % yields while 13–15 gained 95.2–99.0 % yields all at 25 °C and 0.1 MPa CO pressure. The Lewis acidic property of the aluminium compounds 5–8 was investigated. The kinetic of the catalytic reaction using compound 10 was studied. The cooperatively catalytic reaction mechanism by the Co−Al bimetallic species is proposed.

Propylene carbonate synthesis routes using CO2: DFT and thermodynamic analysis

Propylene carbonate (PC) is utilized to improve performance and stability in lithium-ion batteries as an electrolyte component and as a high-performance solvent in paints, varnishes, and adhesives. It is a versatile chemical used in many different industries. It also functions as a plasticizer in polymers and a solvent in pharmaceutical and cosmetic formulations. In the current work, chemical equilibrium analyses of a number of potential processes involved in the synthesis of PC were conducted. To examine the thermodynamic viability of all five approaches, the fluctuation of ΔGmo with temperature for the key processes of PC synthesis was investigated in a specific temperature range of 25 °C-180 °C and at 1 bar and 60 bar pressures. The heat capacity values were estimated using the Rozicka-Domalski method. Benson Group-Increment Theory (BGIT) was used to evaluate the unknown ΔfH for a molecule. By examining the impact of temperature (25 °C-180 °C) and pressure (0–100 bars) on chemical equilibrium constant and equilibrium conversion of reactants, the main reactions of PC synthesis pathways were compared. It was discovered that the one-pot synthesis route and the o-chloropropanol and CO2 approach were superior. The DFT calculations were performed to study the energy changes taking place to convert propylene, glycerol, and propylene glycol (PG) into PC. Both thermodynamic and DFT calculations proved that the PG and urea route is the least favorable for synthesizing PC.

Large scale atomistic and quantum mechanical study of Na+ ion transport in liquid electrolytes for batteries

Lithium–ion batteries (LIBs) have long dominated energy storage markets due to their high energy density and reliability. However, concerns over lithium scarcity and geographic distribution necessitate alternatives. Sodium-ion batteries (SIBs) offer a promising solution due to sodium's abundance, cost-effectiveness, and favorable electrochemical properties. This study investigates Na+ ion transport, aggregation, and performance in various organic electrolytes using molecular dynamics (MD) simulations and density functional theory (DFT) calculations. The electrolytes studied include ethylene carbonate (EC), propylene carbonate (PC), dimethoxyethane (DME), and dimethyl carbonate (DMC) at 320 K. We focused on conductivity, diffusivity, and survival probability of Na+ ions at different salt concentrations. Furthermore, the solvation structure and the binding energy of ions in the electrolytes are thoroughly analyzed. Key findings reveal that at 2 M salt concentration, Na+ ion diffusivity and ionic conductivity follow the order EC>PC>DME>DMC. Increasing salt concentration decreases self–diffusion coefficients of Na+ and PF6− ions across all electrolytes, affecting conductivity. EC shows the highest ionic conductivity at both 1 M and 2 M salt concentrations. These insights suggest that a 2 M NaPF6 concentration in EC optimizes ionic conductivity, making it ideal for high–performance SIBs. This study provides crucial understanding for optimizing electrolytes in SIBs, advancing their development for scalable energy storage solutions.

The polytannic acid‐Fe(III) functionalized graphene oxide in poly (propylene carbonate) nanocomposite enabling enhanced shape memory, UV‐resistance, and self‐healing performance

AbstractPolypropylene carbonate (PPC) is a promising candidate of substrate materials used for human wearable devices due to its excellent ductility and biocompatibility. However, PPC is prone to be deformed, thus resulting in poor shape recovery property. One effective solution is to construct composites. In this work, poly (tannic acid) with Fe3+ (FPTA) @ graphene oxide (GO) was added to fabricate FPTA@GO/PPC composites. The results show that FPTA@GO can construct a tight network of hydrogen bonds into PPC to improve shape memory and self‐healing properties. By varying the FPTA@GO content, the composites exhibit tunable shape memory property. Dynamic mechanical analysis confirms that FPTA@GO/PPC composites show better shape memory properties compared with pure PPC. 5 wt% FPTA@GO/PPC composite demonstrates superior shape fixation ratio (Rf = 99%) as well as superior shape recovery ratio (Rr = 94%) in 37°C. Moreover, 5 wt% FPTA@GO/PPC composite possesses great self‐healing efficiency of 81% and tensile strength (17.2 MPa). The UV absorption capacity of 5 wt% FPTA@GO/PPC is increased by 150% (far and mid‐UV regions) and 400% (near‐UV region) compared with pure PPC. Thus, FPTA@GO/PPC composites have potential applications in developing shape memory, self‐healing, and UV‐resistant materials for human wearable devices.

Kinetic insights into energy-saving and low-carbon reactive distillation processes for the transesterification to dimethyl carbonate

The transesterification of propylene carbonate (PC) or ethylene carbonate (EC) to dimethyl carbonate (DMC) by using catalytic reactive distillation (RD) is a promising approach for carbon dioxide utilization. However, there is still scarcity of comprehensive comparison between the two RD processes. Hence, using the UNIQUAC model and kinetics calibrated by literature and our experiments, we conduct an extensive comparison of the two RD processes. Based on the kinetic insights, laboratory RD processes for both reactions are modeled, analyzed, and experimentally validated. Consequently, two RD processes designed to produce 60 ktpy of DMC are optimized and compared. The interplay and control factors between reaction and separation are elucidated and clarified via investigating variations of the actual chemical equilibrium constant profile compared with theoretical values along the reactive section at various pressures, liquid holdups, etc. The results reveal that the optimized EC RD process achieves almost 50 % reductions in both total annual cost and carbon dioxide emission compared to the PC RD process. This work facilitates the carbon neutrality and provides an essential guide for quantitatively assessing the two routes.