MPa Of CO2 Research Articles

Construction of the Co3O4/Nb2O5 Composite Catalyst with a Prickly Spherelike Architecture for CO2 Cycloaddition with Styrene Oxide.

A high-performance Nb2O5-based catalyst for the cycloaddition of CO2 with SO is designed by properly unifying the concepts of compositional regulation and architectural engineering. The Co3O4/Nb2O5 composite catalyst shows an intriguing prickly spherelike morphology. It exhibits a high styrene carbonate (SC) yield of 94.3% within 4 h (0.0824 mol g-1 h-1) under mild reaction conditions (0.4 MPa of CO2 and a reaction temperature of 90 °C) assisted by tetrabutylammonium bromide (TBAB). The coupling of Co3O4, which chemically interacts with Nb2O5, can effectively modulate the electronic structures of Nb2O5, constructing abundant acid/base sites for effectively activating the reactants and boosting the intrinsic activity. The high activity, cost-effectiveness, and good recyclability make the tailor-made Co3O4/Nb2O5 prickly spheres more appealing for commercial applications. This work offers new insights into designing and constructing well-integrated metal oxide composites for the cycloaddition of CO2 with an epoxide.

High-concentrated synthesis of surface modified iron oxide nanoparticles using ethanol-enhanced supercritical CO2 media

In the synthesis of surface modified metal oxide nanoparticles (NPs), supercritical CO2 is an attractive medium to achieve a simple and green chemistry approach without waster liquor. However, the mass production of surface-modified NPs is still a serious challenge for their industrial utilization. In this work, we aimed to demonstrate the high-concentrated synthesis of surface-modified iron oxide NPs in ethanol-enhanced supercritical CO2. The synthesis and phase observation were performed at 30.0 ± 0.8 MPa of CO2, 100 °C and 18 h, while changing the total concentration of iron(Ⅲ) acetylacetonate, water and oleic acid and ethanol ratio. As a result, lower total concentration gave single nano-sized α-Fe2O3 nanocrystal under uniform phase while higher one gave aggregated α-FeOOH under ununiform phase. However, ethanol entrainer successfully homogenized the reaction field by drastically raising the solubilities of components, allowing the high-concentrated synthesis of single nano-sized α-Fe2O3 nanocrystal. Furthermore, synthesized nanocrystal had chemically and densely modified surface, showing the unimodal size distribution in cyclohexane. These results conclusively show that supercritical CO2 with ethanol entrainer is a promising medium to allow the mass production of densely modified nanocrystal and subsequent their industrial utilization in thin film fabrication and drug delivery system.

Iron(III) Complexes with Pyridine Group Coordination and Dissociation Reversible Equilibrium: Cooperative Activation of CO2 and Epoxides into Cyclic Carbonates.

Herein, a series of [ONSN]-type iron(III) complexes were synthesized. A binary catalytic system in combination with iron complexes and tetrabutylammonium bromide (TBAB) exhibited high activity for the synthesis of cyclic carbonates from CO2 (1 atm) and terminal epoxides at room temperature. Additionally, single-component iron complexes without using additional TBAB as nucleophiles also showed high activity for the cycloaddition of CO2 and terminal epoxides under 80 °C and 0.5 MPa of CO2. This study demonstrates that single-component iron catalysts provide a competitive alternative to binary catalytic systems for the synthesis of cyclic carbonates from CO2 and epoxides. Mechanistic studies on a single-component iron catalytic system suggest that the temperature serves as a role of responsive switch for controlling the coordination and dissociation of pyridine bearing iron catalysts detected using in situ infrared spectroscopy, and uncoordinated pyridine activates CO2 to form carbamate. Studies of electrospray ionization high-resolution mass spectrometry reveal that an iron center was used as a Lewis acidic site, free halogen anions from the iron center were used as a nucleophilic site, and coordinated pyridine was released from iron complexes to activate CO2.

Recyclable N-Heterocyclic Carbene Porous Coordination Polymers with Two Distinct Metal Sites for Transformation of CO2 to Cyclic Carbonates.

Single-component catalysts with integrated multiple reactive centers could work in concert to achieve enhanced activity tailored for specific catalytic reactions, but they remain underdeveloped. Herein, we report the construction of heterogeneous bimetallic porous coordination polymers (PCPs) containing both porphyrin and N-heterocyclic carbene (NHC) metal sites via the coordinative assembly of the NHC functionalities. Three heterobimetallic PCPs (TIPP-Zn-Pd, TIPP-Cu-Pd and TIPP-Ni-Pd) have been prepared to verify this facile synthetic strategy for the first time. In order to establish a cooperative action toward the catalytic CO2 cycloaddition with epoxides, an additional tetraalkylammonium bromide functionality has also been incorporated into these polymeric structures through the N-substituent of the NHC moieties. The resulting heterogeneous bimetallic catalyst TIPP-Zn-Pd exhibits the best catalytic performance in CO2 cycloaddition with styrene oxide (SO) under solvent-free conditions at atmospheric pressure and is applicable to a wide range of epoxides. More importantly, TIPP-Zn-Pd works smoothly and is recyclable in the absence of a cocatalyst under 1.0 MPa of CO2 at 60 °C. This indicates that TIPP-Zn-Pd is quite competitive with the reported heterogeneous catalysts, which typically require a high reaction temperature above 100 °C under cocatalyst-free conditions. Thus, this work provides a new approach to design heterogeneous bimetallic PCP catalysts for high-performance CO2 fixation under mild reaction conditions.

Single-component systems of iron(II) half-sandwich complexes catalyze epichlorohydrin/CO2 condensation

Half-sandwich Fe(II) complexes bearing 2-(diphenylphosphino)ethylamine chelating ligand [(η5-C5H5)Fe(CO)(NH2(CH2)2PPh2)]X, where X = I (1), Br (2), Cl (3), OTf (4) were successfully prepared under mild reaction conditions. Their catalytic activity was evaluated systematically on the (chloromethyl)ethylene carbonate synthesis starting from CO2 and epichlorohydrin. The influence of the counterion has been established, where the single-component catalyst 1 showed low catalytic activity under mild conditions for CO2 and epoxide condensation. The exchange of iodide by bromide showed a higher catalytic activity and a higher conversion with compound 2 as a catalyst, while a decrease and no conversion were observed for 3 (X = Cl) and 4 (X = OTf), respectively. Optimization of the catalytic conditions was carried out using epichlorohydrin in dry chloroform, along with modification of the reaction conditions. Of the synthesized compounds (1–4), only 2 showed conversions to (chloromethyl)ethylene carbonate >99 % at 100 °C, 0.34 MPa of CO2, 14 h and 2 % mol of catalyst, or by modifying the temperature to 80 °C and the pressure to 0.69 MPa of CO2. Catalyst 2 proved to be very selective, although it has modest activity, reaching low values of TON (124) and TOF (8.17 h−1).

Synthesis of dimethyl carbonate from CO2 and methanol over CeO2 catalysts prepared by soft-template precipitation and hydrothermal method

Direct synthesis of dimethyl carbonate (DMC) from methanol (MeOH) and carbon dioxide (CO2) is a promising environmentally-friendly process for utilizing CO2 as a source of useful chemicals. For this reaction, CeO2 is known as an effective catalyst, and a variety of CeO2 catalysts prepared via various synthetic methods for controlling textural and surface properties of CeO2 such as facets, particle shapes, acidity, basicity, and oxygen vacancies have been employed. In this study, CeO2 catalysts were prepared via the combination of soft-template precipitation and hydrothermal treatment followed by calcination at different temperatures, and their catalytic performance for the DMC synthesis was investigated in the presence of 2-cyanopyridine (2-CP) as a dehydrating agent. CeO2 calcined at 650 °C (CeO2(650)) exhibited the highest DMC yield among the catalysts prepared in this study under the identical conditions. Its catalytic performance represented by the DMC formation rate at 110 °C was 31 mmol gcat−1 h−1 at 5 MPa of CO2 and MeOH/2-CP molar ratio of 1.0, and this rate was comparable to the previously reported highest value of 42 mmol gcat−1 h−1 under the similar reaction conditions consisting of reaction temperature of 110 ± 20 °C, CO2 pressure of 5 ± 1 MPa, and molar ratio of MeOH/2-CP of 0.5–2.0. Among the surface acidity and basicity examined by the temperature-programmed desorption measurements, the amount of base sites with medium strength of the prepared CeO2 catalysts was in the same order as the DMC amount. The infrared spectroscopy for the CO2 species chemisorbed on the CeO2 surfaces suggested the formation of bicarbonate species on the base sites with medium strength.

Itraconazole cocrystal formation using fatty acid media under high pressure CO2

In pharmaceutics, rapid and safe cocrystallization of drugs with large molecular weight is still a serious challenge. In this research, we develop a new cocrystallization method using fatty acid under high-pressure CO2. The cocrystallization of itraconazole, which has large molecular weight, and succinic acid was performed at 0.1–15.0 MPa of CO2 and 50–60 °C for 2 h while using stearic acid, oleic acid and linoleic acid as fatty acids. As a result, fatty acid under high-pressure CO2 (more than 5.0 MPa) significantly promoted the itraconazole cocrystallization compared to those in only fatty acid or in high-pressure CO2. Additionally, the main roles of fatty acid and high-pressure CO2 are suggested to be the cocrystallization field and the reduction of its viscosity, respectively. These findings support that fatty acid under high-pressure CO2 is a new promising filed to rapidly and safely achieve the cocrystallization of drugs with large molecular weight.

Formation mechanism of surface modified iron oxide nanoparticles using controlled hydrolysis reaction in supercritical CO2

In the synthesis of surface modified nanoparticles (NPs), supercritical CO2 is one of appealing reaction fields to realize simple and green chemistry approach without using an organic solvent. In this work, surface modified iron oxide NPs was synthesized in supercritical CO2 with various amounts of water between 5.0 and 90.0 mmol to elucidate the formation mechanism of surface modified NPs with the hydrolysis reaction. The synthesis was performed at 30.0 ± 0.9 MPa of CO2, 18 h and 100 °C, where iron(Ⅲ) acetylacetonate, water and oleic acid were used as starting materials. As a result, the smaller amount of water was revealed to be key factor to synthesize more densely modified iron oxide NPs without the aggregation and iron oxyhydroxide formation while the larger amount of water caused the sever aggregation of less modified NPs and the formation of iron oxyhydroxide. Additionally, the detailed analysis of iron oleate complex and the phase state prediction suggested that the smaller amount of water allowed more dominated formation of iron oleate and subsequent its hydrolysis reaction in uniform supercritical CO2 phase, resulting in the formation of densely modified NPs without the aggregation.

I-LDH as a heterogeneous bifunctional catalyst for the conversion of CO2 into cyclic organic carbonates

In this work, we prepared a new active heterogeneous, single-component, catalyst (I-(Mg/Al)LDH) for the cycloaddition reaction of CO2 to epoxides. I-LDH was able to catalyze this reaction selectively to cyclic organic carbonates. From a mechanistic point of view, iodide anions within the interlayer and the hydroxide group of the LDH cooperate in the cycloaddition reaction. The reaction conditions (T = 80 °C, 2 MPa of CO2, methyl ethyl ketone as a solvent, PO:I-LDH wt ratio of 1.7, 24 h) were optimized using propylene oxide, with a conversion up to 47% and a total selectivity to the cyclic carbonate and then the study was extended to other commercial epoxides with encouraging results. The reversible I-LDH poisoning due to the absorption of CO2 as unreactive carbonate interlayer anion was also investigated and the catalyst was reactivated by treatment in a concentrated KI aqueous solution.

Preparation of several novel Salen-Co(III) visible photocatalysts and their application in the copolymerization of carbon dioxide with propylene oxide

Carbon dioxide (CO2) is a renewable carbon source, which can be copolymerized with epoxide to prepare aliphatic polycarbonate and cyclic carbonate. In this paper, a series of novel SalenCo(III) photocatalysts were synthesized for the first time, and the copolymerization of CO2 and propylene oxide (PO) was studied. The effects of reaction conditions on catalytic activity and selectivity were investigated. The results show that the catalyst 3 with strong polarity Schiff base and planar conjugated dye has the highest activity and selectivity for CO2 and PO photocopolymerization among the four SalenCo(III) photocatalysts. Due to the synergistic action of the catalyst and Mn4Ca nanocluster, the ring-opening of PO is promoted and the photocatalytic efficiency is greatly improved. The introduction of visible light improves the catalytic efficiency, and increasing light intensity can better improve the catalytic efficiency. The optimal copolymerization condition was 60 °C, 6 h, 200 W, 2 MPa of CO2 with Mn4Ca nanocluster/catalyst 3.

Novel MOF catalysts based on calix[4]arene for the synthesis of propylene carbonate from propylene oxide and CO2

In this study, novel composite materials based on calix[4]arene with hydroxyl groups in the arene “bowl” (K-OH) and the aluminum(III) 2-aminoterephthalate metal organic framework (NH2-MIL-101(Al), MIL) have been synthesized according to in situ or “bottle around ship” strategy. The effect of the synthesis method, i.e., MW-assisted technique (MW) and the solvothermal procedure (Solv), on the structural, morphological, textural and catalytic properties of MIL/K-OH composites was demonstrated. Catalytic performance of the MIL/K-OH(MW) and MIL/K-OH(Solv) composites was studied in solvent-free coupling of CO2 and propylene oxide (PO) to produce propylene carbonate (PC) at 0.8 MPa of CO2 and 80 °C. The activity of the MIL/K-OH(Solv) catalyst was higher in comparison with MIL/K-OH(MW) material as a result of the differences in the textural properties. The binary system MIL/K-OH(MW)/[n-Bu4N]Br was demonstrated to be a promising catalyst for cycloaddition of CO2 to PO. In its presence, the conversion of PO was 77 % with 99 % selectivity towards PC at 1.2 MPa of CO2, 50 °C for 24 h.

Surface analyses of low carbon steel and stainless steel in geothermal synthetic Na-Ca-Cl brine saturated with CO[formula omitted

In a geothermal power plant, certain precautions should be taken to ensure a good efficiency. Indeed, it is important to avoid degassing of the geothermal fluid and to prevent corrosion issues. To address these problems, the gas–liquid equilibrium has to be controlled and the characteristics (composition, temperature…) of the fluid known as well as the nature of the material used.For this reason, in this paper, a laboratory-scale device was developed in order to simulate natural like conditions and achieve corrosion tests. The corrosion behaviour of two materials, a carbon steel (DC01) and a stainless steel (304 L), has been investigated. The testing materials have been exposed to a synthetic brine which composition is similar to the Upper Rhine Graben water formation. The brine was saturated with 2 MPa of CO2 and heated up to 50 °C and 100 °C.Surfaces of tested metals were analysed by spectroscopic (XPS) and microscopic (SEM) methods in order to characterize corrosion products and to get more information onto the corrosion mechanisms process.The use of the laboratory prototype coupled with surface analysis methods allowed to better understand CO2 corrosion in geothermal environment. The role of the brine chemistry and the impact of temperature and CO2 dissolved concentration have been studied in this work. Indeed, different natures of corrosion products regarding the material composition and microstructure have been highlighted. A mixture of CaCO3 and FeCO3 scale is identified on the carbon steel whereas the stainless steel exhibits a mixture of Cr(OH)3 and FeCO 3 on its surface.

Application of pervaporation membranes to the direct carboxylation of ethene glycol using CeO2-based catalysts—Comparison of the batch reaction to a flow reaction in SC-CO2

The reaction between ethene glycol-EG and CO2 to afford the cyclic ethene carbonate-EC has been studied in solvent-less conditions and in absence of water traps but using pervaporation membranes to eliminate water. The parameter space of the reaction (temperature, pressure, catalyst loading, time of reaction) has been investigated, filling a gap existing in the scientific literature, and the optimal reaction conditions set as: 408 K, 2 h, 10% w/w cat, 5.0 MPa of CO2. Under such conditions an equilibrium constant equal to 8.3 × 10−4 has been calculated based on the equilibrium composition of the reaction mixture that contains 0.33% mol of EC. Such value is higher than that calculated from available thermodynamic data in the scientific literature (3 ×10−26) showing that they need a correction to be adapted to a condensed phase. Using a SC-mixture of EG and CO2 (with a molar ratio CO2/EG equal to 60), 0.25 ± 0.01% EC is formed in a contact-time of the order of 4–6 min with respect to 120 min in a batch reaction, justified by the higher CO2/EG molar ratio. Water is formed in excess with respect to the reaction stoichiometry, due to parasite reactions that bear to the formation of di- and tri-ethers and linear carbonate. Such excess water (up to ten times the expected value) strongly influences the equilibrium composition and disfavour the formation of EC. The application of a NaA-type pervaporation membrane can increase the EC-equilibrium concentration of 3–4 times. EG is shown to be less performant than ethanol due to the easier etherification that causes extra-formation of water, that pushes the equilibrium to the left, and to its viscosity that affects the performance of the membrane. The reaction time must be kept under control as a long reaction time favours the formation of ethers, more than EC. A DFT study aimed to explore suitable intermediate species in the catalysed reaction explains that etherification and carbonation are competitive reactions.

Synthesis of surface-modified iron oxide nanocrystals using supercritical carbon dioxide as the reaction field.

In the synthesis of surface-modified nanocrystals (NCs), a simple and green chemistry approach to reduce liquid waste, particularly a solventless process, has been desired. In this study, we applied the supercritical CO2 technology, which is an excellent solventless process, to the synthesis of surface-modified iron oxide NCs. The synthesis was performed at 30.0 ± 0.8 MPa of CO2, 18 h and 100 °C, where iron(iii) acetylacetonate, pure water and decanoic acid were used as starting materials. As a result, the supercritical CO2 medium gave the NCs of α-Fe2O3 and γ-Fe2O3 with unimodal size distribution, where the mean size was 7.8 ± 2.0 nm. In addition, they were self-assembled on the TEM substrate and the mean nearest-neighbor spacing was close to the chain length of decanoic acid. Furthermore, FT-IR and TG analyses indicate that decanoic acid chemically attaches to the surface of iron oxide NCs that are dispersed in cyclohexane. These results suggest that the supercritical CO2 medium could be the new appealing reaction field to fabricate densely modified NCs without liquid waste.

Synthesis of diethyl carbonate from CO2 and orthoester promoted by a CeO2 catalyst and ethanol

The combination of a CeO2 catalyst and ethanol effectively promotes the direct synthesis of diethyl carbonate (DEC) from CO2 and an orthoester. The reaction temperature, initial CO2 pressure, and the ethanol/orthoester volume ratio were found to significantly influence DEC formation and were systematically studied to determine the optimum conditions. DEC amount of 5.2 mmol was obtained at 160 °C, 5 MPa of CO2, and a reaction time of 20 h, providing high productivity (1.21 mmolDEC mmolcatalyst−1 h−1) using a CeO2 catalyst. The recovered CeO2 catalyst was recyclable at least four times without any significant loss of activity when both triethyl orthoacetate and triethyl orthovalerate were used. A series of orthoesters bearing various alkyl substituents, aromatic substituents and halide moieties were evaluated for their activities with and without ethanol. In the presence of ethanol, orthoesters bearing longer alkyl substituents led to higher DEC yields, and orthoesters bearing aromatic and halide moieties negatively impacted DEC formation. In the absence of ethanol, triethyl orthoacetate provided the highest DEC yield; in all cases, the use of ethanol resulted in a greater DEC formation than when the reaction was performed without ethanol.

Synthesis of Diverse Polycarbonates by Organocatalytic Copolymerization of CO2 and Epoxides: From High Pressure and Temperature to Ambient Conditions

AbstractOrganophosphazenes combined with triethylborane (TEB) were selected as binary organocatalyts for the copolymerization of CO2 and epoxides. Both the activity and selectivity were highly dependent on the nature of phosphazenes. 2,4,6‐Tris[tri(1‐pyrrolidinyl)‐iminophosphorane]‐1,3,5‐triazine (C3N3‐Py‐P3) with a relatively low basicity (pKa=26.5 in CD3CN) and a bulky molecular size (φ=1.3 nm) exhibited an unprecedented efficiency (TON up to 12240) and selectivity (>99 % polymer selectivity and >99 % carbonate linkages) toward copolymerization of CO2 and cyclohexene oxide (CHO), and produced CO2‐based polycarbonates (CO2‐PCs) with high molar masses (Mn up to 275.5 kDa) at 1 MPa of CO2 and 80 °C. Surprisingly, this binary catalytic system achieved efficient CO2/CHO copolymerization with TOF up to 95 h−1 at 1 atm pressure and room temperature.

Synthesis of Diverse Polycarbonates by Organocatalytic Copolymerization of CO2 and Epoxides: From High Pressure and Temperature to Ambient Conditions.

Organophosphazenes combined with triethylborane (TEB) were selected as binary organocatalyts for the copolymerization of CO2 and epoxides. Both the activity and selectivity were highly dependent on the nature of phosphazenes. 2,4,6-Tris[tri(1-pyrrolidinyl)-iminophosphorane]-1,3,5-triazine (C3 N3 -Py-P3 ) with a relatively low basicity (pKa =26.5 in CD3 CN) and a bulky molecular size (φ=1.3 nm) exhibited an unprecedented efficiency (TON up to 12240) and selectivity (>99 % polymer selectivity and >99 % carbonate linkages) toward copolymerization of CO2 and cyclohexene oxide (CHO), and produced CO2 -based polycarbonates (CO2 -PCs) with high molar masses (Mn up to 275.5 kDa) at 1 MPa of CO2 and 80 °C. Surprisingly, this binary catalytic system achieved efficient CO2 /CHO copolymerization with TOF up to 95 h-1 at 1 atm pressure and room temperature.

Effect of MAF-6 Crystal Size on Its Physicochemical and Catalytic Properties in the Cycloaddition of CO2 to Propylene Oxide

Zeolitic imidazolate frameworks MAF-5 and MAF-6 based on Zn2+ and 2-ethylimidazole were demonstrated to be efficient heterogeneous catalysts in solvent-free coupling of CO2 and propylene oxide (PO) to produce propylene carbonate (PC) at 0.8 MPa of CO2 and 80 °C. Activity of MAF-5 was lower in comparison with MAF-6 due to the difference in their structural and textural characteristics. MAF-6 samples with particle size of 190 ± 20, 360 ± 30, and 810 ± 30 nm were prepared at room temperature from [Zn(NH3)4](OH)2 and 2-ethylimidazole. Control of particle size was achieved by variation of type of alcohol in alcohol/cyclohexane media for the preparation of MAF-6. According to this comprehensive study, the yield of PC was found to decrease with increasing crystal size of the MAF-6 material, which was related to the change in textural properties and the number and localization of active sites. The combination of MAF-6 with particle size of with particle size of 190 ± 20 nm and tetrabutylammonium bromide ([n-Bu4N]Br) as co-catalyst led to an approximately 4-fold enhancement in the yield of PC (80.5%). Compared with reported ZIFs catalysts, the efficiencies of MAF-5/[n-Bu4N]Br and MAF-6/[n-Bu4N]Br binary systems were comparable and higher under similar reaction conditions.

A Bio-Based Alginate Aerogel as an Ionic Liquid Support for the Efficient Synthesis of Cyclic Carbonates from CO2 and Epoxides

In this work, the ionic liquid [Aliquat][Cl] was supported into alginate and silica aerogel matrices and applied as a catalyst in the cycloaddition reaction between CO2 and a bio-based epoxide (limonene oxide). The efficiency of the alginate aerogel system is much higher than that of the silica one. The method of wet impregnation was used for the impregnation of the aerogel with [Aliquat][Cl] and a zinc complex. The procedure originated a well-defined thin solvent film on the surface of support materials. Final materials were characterised by Fourier Transform Infrared Spectroscopy, N2 Adsorption–Desorption Analysis, X-ray diffraction, atomic absorption and Field Emission Scanning Microscopy. Several catalytic tests were performed in a high-pressure apparatus at 353.2 K and 4 MPa of CO2.

Accelerated phase transition and synthesis of magnesite from hydromagnesite in aqueous mono-ethylene glycol solution

Magnesite was successfully synthesized from hydromagnesite by undergoing a phase transition process in mono-ethylene glycol (MEG) solution. The process can be achieved at 393 K under 0.5 MPa of CO2 in 5 h, and the formed particle size of magnesite ranges from 1 to 10 µm depending on the synthesis temperature. This study discloses the effect of MEG concentration with adequate amount of sodium chloride (NaCl) or sodium carbonate (Na2CO3) on the magnesite synthesis process, both of which accelerates the mass transfer rate of CO2 during the transition process. The mixed-solvent electrolyte (MSE) model was applied by constructing the phase diagram of hydromagnesite -magnesite in the Mg-Na-Cl-CO3-CO2-MEG-H2O system. Both the experimental and the calculated results unveiled that the addition of MEG reduces the water activity significantly, which allowed for the phase transition to occur. Additionally, rhombic magnesite can be obtained from hydromagnesite in an aqueous solution at a condition that contains 95 wt% of MEG, 1 mol/kgw. NaCl and 0.285 mol/kgw. of Na2CO3.