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1.
Three silole-containing hypercrosslinked microporous organic polymer networks were designed and synthesized via Friedel–Crafts alkylation promoted by anhydrous FeCl3. The results demonstrated that the substitution of methyl group connected with silicon atom by benzene has negligible effect on the surface area and gas uptake ability of the polymer networks. The network-1 produced from 1,1-dimethyl-2,3,4,5-tetraphenylsilole shows a surface area up to 1236 m2 g−1 with the hydrogen uptake ability of 1.33 wt% (77.3 K/1.13 bar) and a carbon dioxide capture capacity of 2.94 mmol g−1 at 273 K/1.13 bar. The isosteric heats of carbon dioxide sorption for all of the polymer networks exceed 25 kJ/mol at the zero coverage because the introduction of silicon atom into the polymer skeleton enhanced the binding affinity between the adsorbent and CO2 molecules. In addition, the selectivity of the polymer networks for CO2/N2 and CO2/CH4 were found to be around 35 and 6 at 273 K, respectively. These results show that these materials are potential candidates for applications in post-combustion CO2 capture and separation.  相似文献   

2.
Microporous polymelamine network was prepared through one-pot catalyst-free polymerization using the Schiff base reaction. Gas adsorption experiments indicate that the network possesses high CO2 uptake capacity, reaching 89.0 cm3 g?1 (17.9 wt%) at 1.0 bar and 273 K, along with high selectivity towards CO2 over N2 and CH4. The porous polymeric network presents a promising potential as efficient adsorbents in clean energy applications.  相似文献   

3.
A series of high performance carbonaceous mesoporous materials: activated carbon beads (ACBs), have been prepared in this work. Among the samples, ACB‐5 possesses the BET specific surface area of 3537 m2 g?1 and ACB‐2 has the pore volume of 3.18 cm3 g?1. Experimental measurements were carried out on the intelligent gravimetric analyzer (IGA‐003, Hiden). Carbon dioxide adsorption capacity of 909 mg g?1 has been achieved in ACB‐5 at 298 K and 18 bar, which is superior to the existing carbonaceous porous materials and comparable to metal‐organic framework (MOF)‐177 (1232 mg g?1, at 298 K and 20 bar) and covalent‐organic framework (COF)‐102 (1050 mg g?1 at 298 K and 20 bar) reported in the literature. Moreover, methane uptake reaches 15.23 wt % in ACB‐5 at 298 K and 18 bar, which is better than MOF‐5. To predict the performances of the samples ACB‐2 and ACB‐5 at high pressures, modeling of the samples and grand canonical Monte Carlo simulation have been conducted, as is presented in our previous work. The adsorption isotherms of CO2/N2 and CO2/CH4 in our samples ACB‐2 and 5 have been measured at 298 and 348 K and different compositions, corresponding to the pre‐ and postcombustion conditions for CO2 capture. The Dual‐Site Langmuir‐Freundlich (DSLF) model‐based ideal‐adsorbed solution theory (IAST) was also used to solve the selectivity of CO2 over N2 and CH4. The selectivities of ACBs for CO2/CH4 are in the range of 2–2.5, while they remain in the range of 6.0–8.0 for CO2/N2 at T = 298 K. In summary, this work presents a new type of adsorbent‐ACBs, which are not only good candidates for CO2 and CH4 storage but also for the capture of carbon dioxide in pre‐ and postcombustion processes. © 2011 American Institute of Chemical Engineers AIChE J, 2011  相似文献   

4.
For the first time, microporous polyamide networks have been synthesized via the interfacial polymerization of piperazine and acyl chloride monomers containing tetrahedral carbon and silicon cores. These polyamides, with Brunauer–Emmett–Teller surface area between 488 and 584 m2 g?1, show a CO2 uptake of up to 9.81 wt% and a CO2/N2 selectivity of up to 51 at 1 bar and 273 K, suggesting their great potential in the area of carbon capture and storage applications. We have developed the interfacial polymerization on the surface of the porous polyacrylonitrile substrate, resulting in the formation of ultrathin microporous membranes with thicknesses of about 100 nm. These nanofiltration (NF) membranes exhibited an attractive water flux of 82.8 L m?2 h?1 at 0.4 MPa and a high CaCl2 (500 mg/L) rejection of 93.3%. These NF membranes follow the salt rejection sequence of CaCl2 > NaCl > Na2SO4, demonstrating the positively charged character of these membranes.  相似文献   

5.
The increase in CO2 concentration in the atmosphere has led to global warming, which draws great attention all over the world. Adsorption is considered as an effective method for CO2 capture and stabilizing the increasing CO2 concentration. Metal–organic frameworks (MOFs) are promising materials for carbon capture. However, the direct use of MOF powders may lead to issues such as high pressure drop, pipe clogging, and handling difficulties in applications. Herein, a phase inversion strategy is reported to prepare SIFSIX-3-Ni@PAN composite beads. The prepared composites exhibit hierarchically porous structure with uniform MOF distribution inside the materials and good mechanical stability. The MOF content can be well controlled and composites with up to 70% loading are prepared. Finally, the obtained materials possess high CO2 capture capacity, even at low CO2 concentrations (1.19 mmol g−1 at 0.01 bar and 298 K).  相似文献   

6.
Due to its toxicity and corrosiveness, it is of enormous significance to efficiently capture and recover sulfur dioxide (SO2) from flue gas and natural gas. Herein, a new type of IL/MIL-0.7 composite was precisely designed to meet this challenge, which exhibits a high adsorption capacity for SO2 (13.17 mmol g−1) at 298 K and 1.0 bar while excludes almost completely carbon dioxide (CO2, 0.27 mmol g−1) and nitrogen (N2, 0.07 mmol g−1). The high IAST selectivity (at least 11,925) of IL/MIL-0.7 for SO2/CO2 can be achieved within the whole test pressure range. In addition, the breakthrough experiment also confirmed the excellent performance of the composite for deep removal of 2000 ppm SO2. Furthermore, the IL/MIL-0.7 composites can maintain excellent performance after four adsorption/desorption cycles and the thermostability can up to ~450 K. Therefore, this stable IL/MOF composite has the potential application as an effective adsorbent for SO2 removal from flue gas and natural gas.  相似文献   

7.
Novel hypercrosslinked microporous organic polymers (MOPs) derived from N‐functionalized siloles as basic building units have been designed and synthesized via Friedel–Crafts alkylation reaction. The resulting N‐functional silole‐containing polymer networks exhibit high thermal stabilities and moderate Brunauer–Emmett–Teller surface area ranging from 666 to 1137 m2 g?1. The incorporation of carbazole or triphenylamine moieties into the polymer skeleton increases the number of electron donating basic nitrogen sites in the porous frameworks. Thus, the corresponding polymer PDMCzS shows enhanced CO2 adsorption capacities of 3.23 mmol g?1 at 273 K and 1.13 bar, and higher CO2/N2 selectivity (43.99) at 273 K than the analogous silole‐containing polymers P1–P3. These results demonstrated that the N‐functionalized silole‐containing polymer network is a very promising candidate for potential applications in post‐combustion CO2 capture and sequestration. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45907.  相似文献   

8.
S-doped microporous carbon materials were synthesized by the chemical activation of a reduced-graphene-oxide/poly-thiophene material. The material displayed a large CO2 adsorption capacity of 4.5 mmol g−1 at 298 K and 1 atm, as well as an impressive CO2 adsorption selectivity over N2, CH4 and H2. The material was shown to exhibit a stable recycling adsorption capacity of 4.0 mmol g−1. The synthesized material showed a maximum specific surface area of 1567 m2 g−1 and an optimal CO2 adsorption pore size of 0.6 nm. The microporosity, surface area and oxidized S content of the material were found to be the determining factors for CO2 adsorption. These properties show that the as synthesized S-doped microporous carbon material can be more effective than similarly prepared N-doped microporous carbons in CO2 capture.  相似文献   

9.
Developing absorbents with both high absorption capacity of H2S and large selectivity of H2S/CO2 is very important for natural gas sweetening process. To this end, a class of novel hydrophobic protic ionic liquids (ILs) containing free tertiary amine group as functional site for the absorption of H2S were designed in this work. They were facilely synthesized through a simple neutralization‐metathesis methodology by utilizing diamine compounds and bis(trifluoromethylsulfonyl)imide as the building blocks for cation and anion, respectively. Impressively, the solubility of H2S can reach 0.546 mol mol?1 (1 bar) and 0.225 mol mol?1 (0.1 bar), and the selectivity of H2S/CO2 can reach 37.2 (H2S solubility at 1 bar vs. CO2 solubility at 1 bar) and 15.4 (H2S solubility at 0.1 bar vs. CO2 solubility at 1 bar) in the hydrophobic protic ILs at 298.2 K. Comparing the hydrophobic protic ILs with other absorbents justifies their superior performance in the selective absorption of H2S from CO2. © 2016 American Institute of Chemical Engineers AIChE J, 62: 4480–4490, 2016  相似文献   

10.
Porous Polymer Networks (PPNs) are an emerging category of advanced porous materials that are of interest for carbon dioxide capture due to their great stabilities and convenient functionalization processes. In this work, an intrinsically-functionalized porous network, PPN-101, was prepared from commercially accessible materials via an easy two-step synthesis. It has a BET surface area of 1095 m2/g. Due to the presence of the benzimidazole units in the framework, its CO2 uptake at 273 K reaches 115 cm3/g and its calculated CO2/N2 selectivity is 199, which indicates its potential for CO2/N2 separation. The great stability, large CO2/N2 selectivity and low production cost make PPN-101 a promising material for industrial separation of CO2 from flue gas. Its H2 and CH4 uptake properties were also investigated.  相似文献   

11.
A cobalt-organic framework (1) consisted of close-packed polyhedral cages is isostructural to CPM-35-Ni. The activated sample (1a) can adsorb high H2 uptake of 88.3 cm3 g 1 (0.79 wt.%) at 77 K and 1.0 bar. Remarkably, 1a shows high CO2 adsorption capacity and good adsorption selectivity for CO2 over CH4 and N2.  相似文献   

12.
A series of renewable nitrogen-containing granular porous carbons with developed porosities and controlled surface chemical properties were prepared from poplar anthers. The preparation conditions such as pre-carbonization and activation temperatures and KOH amount significantly influence the structures and chemical compositions of the porous carbons, the CO2 adsorption capacities of which are highly dependent on their pore structures, surface areas, nitrogen contents and adsorption conditions. The sample with developed microporosity, especially with the pores between 0.43 and 1 nm and high nitrogen content shows high CO2 adsorption capacity at 1 bar and 25 °C. In contrast, when the adsorption pressure is higher than 5 bar, its CO2 adsorption capacity is dominated by its surface area, and more accurately by its pore volume. Irrespective of this, if the pressure was decreased to 0.1 bar, its CO2 capture ability is closely correlated to its nitrogen content but not to its porosity. By optimizing the preparation conditions, a porous carbon with a surface area of 3322 m2 g−1 and a CO2 adsorption capacity as high as 51.3 mmol g−1 at 50 bar and 25 °C was prepared.  相似文献   

13.
In this work, we examine the use of the amidoxime functional group grafted onto a hierarchical porous carbon framework for the selective capture and removal of carbon dioxide from combustion streams. Measured CO2/N2 ideal selectivity values for the amidoxime-grafted carbon were significantly higher than the pristine porous carbon with improvements of 65%. Though the overall CO2 capacity decreased slightly for the activated carbon from 4.97 mmol g−1 to 4.24 mmol g−1 after surface modification due to a reduction in the total surface area, the isosteric heats of adsorption increased after amidoxime incorporation indicating an increased interaction of CO2 with the sorbent. Total capacity was reproducible and stable after multiple adsorption/desorption cycles with no loss of capacity suggesting that modification with the amidoxime group is a potential method to enhance carbon capture.  相似文献   

14.
We herein report an optimal modulated hydrothermal (MHT) synthesis of a highly stable zirconium metal‐organic framework (MOF) with an optimum aperture size of 3.93 Å that is favorable for CO2 adsorption. It exhibits excellent CO2 uptake capacities of 2.50 and 5.63 mmol g?1 under 0.15 and 1 bar at 298 K, respectively, which are among the highest of all the pristine water‐stable MOFs reported so far. In addition, we have designed a lab‐scale breakthrough set‐up to study its CO2 capture performance under both dry and wet conditions. The velocity at the exit of breakthrough column for mass balance accuracy is carefully measured using argon with a fixed flow rate as the internal reference. Other factors that may affect the breakthrough dynamics, such as pressure drop and its impact on the roll‐up of the weaker component have been studied in details. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4103–4114, 2017  相似文献   

15.
Yongde Xia  Yanqiu Zhu  Yi Tang 《Carbon》2012,50(15):5543-5553
Structurally well ordered, sulfur-doped microporous carbon materials have been successfully prepared by a nanocasting method using zeolite EMC-2 as a hard template. The carbon materials exhibited well-resolved diffraction peaks in powder XRD patterns and ordered micropore channels in TEM images. Adjusting the synthesis conditions, carbons possess a tunable sulfur content in the range of 1.3–6.6 wt.%, a surface area of 729–1627 m2 g?1 and a pore volume of 0.60–0.90 cm3 g?1. A significant proportion of the porosity in the carbons (up to 82% and 63% for surface area and pore volume, respectively) is contributed by micropores. The sulfur-doped microporous carbons exhibit isosteric heat of hydrogen adsorption up to 9.2 kJ mol?1 and a high hydrogen uptake density of 14.3 × 10?3 mmol m?2 at ?196 °C and 20 bar, one of the highest ever observed for nanoporous carbons. They also show a high CO2 adsorption energy up to 59 kJ mol?1 at lower coverages (with 22 kJ mol?1 at higher CO2 coverages), the highest ever reported for any porous carbon materials and one of the highest amongst all the porous materials. These findings suggest that S-doped microporous carbons are potential promising adsorbents for hydrogen and CO2.  相似文献   

16.
17.
In this work a comprehensive study was undertaken to characterize the porous nature of a fully exchanged potassium chabazite zeolite (KCHA) and evaluate its adsorption properties under different conditions. A synthetic chabazite was prepared from the decomposition of zeolite Y and ion-exchanged to produce a fully exchanged potassium chabazite with Si/Al ratio of 2.4. In addition, sodium chabazite (NaCHA) and lithium chabazite (LiCHA) were synthesized for comparison purposes. Equilibrium isotherms for N2 and CO2 were measured at 273 K for further characterization. Our results show that the porous structure characterization by N2 at 77 K and Ar at 87 K following the standard methods of BET for surface area, t-plot, DR and DFT for pore size distribution and volume reveal pore blockage phenomenon with substantially diminished adsorption capacities. However, CO2 adsorption capacity on KCHA at 273 K reveals magnitudes of 70.1% and 78.7% of those on LiCHA and NaCHA, and a DFT pore volume of 0.214 cm3 g?1. The surface area of KCHA calculated from the CO2 isotherm using the Tóth model in its revised form demonstrates a surface area of 584.4 m2 g?1. This is in contrast to 17.82 and 13.48 m2 g?1 obtained from the BET model using N2 and Ar at 77 and 87 K, respectively. It was concluded that the reliability of standard methods (viz. BET using N2 at 77 K) for characterizing these particular porous solids is questionable under certain circumstances leading to misevaluation of adsorbent properties.  相似文献   

18.
The development of ethane (C2H6)-selective adsorbents for ethylene (C2H4) purification, although challenging, is of prime industrial importance. Pillared-layer metal-organic frameworks (MOFs) possess facilely tunable pore structure and functionality, which means they have excellent potential for high-performance C2H6/C2H4 separation applications. Herein, we report a family of isostructural pillared-layer MOFs with various metal centers M and co-ligands L, M2(D-cam)4L2 (denoted M-cam-L; M = Cu, Co, Ni; L = pyz, apyz, dabco), with a variety of pore surface properties. All of the M-cam-L materials exhibit preferential adsorption for C2H6 over C2H4. In particular, Ni-cam-pyz exhibits the highest C2H6 capture capacity (68.75 cm3 g−1 at 1 bar and 298 K), Cu-cam-dabco possesses the greatest C2H6/C2H4 adsorption selectivity (2.3), and the lowest isosteric heat of adsorption is demonstrated for Cu-cam-pyz (20.1 kJ mol−1). Dynamic column breakthrough experiments also confirmed the excellent separation performance of M-cam-pyz and M-cam-dabco materials. The synthesis route of the M-cam-L materials is easily scaled-up under laboratory conditions, and hence this class of MOFs is promising for practical C2H4 purification.  相似文献   

19.
Anion functionalized strategy has been proposed for the synthesis of macro‐porous resins [IRA‐900][An] through the neutral reaction of the basic resin [IRA‐900][OH] with the corresponding donors. Combining CO2 adsorption results and FT‐IR, solid‐state 13C NMR characterization as well as quantum chemical calculations, chemical adsorption mechanism was verified and tunable capture of CO2 was realized. Among them, the anion functionalized resin [IRA‐900][Triz] exhibits an extremely high adsorption capacity (4.02 mmol g?1 at 25°C, 0.15 bar), outperforming many other good adsorbents. Finally, we discuss the thermostability and recycling stability of [IRA‐900][Triz], which shows a great potential in the industrial capture of CO2. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3008–3015, 2017  相似文献   

20.
Synthesis of covalently linked porous polymers with high surface area and larger pore volume for two or more task-specific functionalities is always a big challenge. In this article, the facile Friedel–Crafts reaction is employed to construct the hierarchical hybrid porous polymers (HPPs) from tetraphenyladamantane and octavinylsilsesquioxane. The resulting polymers, HPP-1 to HPP-3, possessed the surface areas from 1356 to 1511 m2 g−1, and the pore volumes from 2.05 to 2.67 cm3 g−1. All these polymers feature micropores, mesopores, and macropores in nature. The resultant polymers exhibit high CO2 adsorption capacity up to 2.0 mmol g−1 (8.82 wt %), at 273 K, 1.0 bar, and the maximum Rhodamine B (RB) sorption capacity of 653.6 mg g−1. To illustrate the adsorption process, the effects of factors, contact time, initial concentration, temperature, and pH value on the adsorption capacity of RB were studied. The adsorption equilibrium data displayed a better fitting to the Langmuir isotherm model than the Freundlich model and the adsorption kinetics fitted well with the pseudo-second-order kinetic model. The recycle experiments displayed that the capacity recovery was still higher than 95% after four cycles. Theses polymers are promising to be the adsorbents for capturing CO2 and removing RB. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 136, 48572.  相似文献   

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