ACS Applied Materials & Interfaces
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2019
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IF 8.456
Junjie Liu,Ning Qi,Bo Zhou,Zhiquan Chen
A series of amorphous melamine-based polymer networks synthesized by Schiff base chemistry (SNW) were successfully prepared by varying the strut length. The pore structure was analyzed by gas adsorption and positron annihilation methods. Positron lifetime measurements indicate the existence of ultramicropores and also larger mesopores in the SNW materials. The sizes of micropores and mesopores are almost the same in these samples, which are about 0.7 and 16.5 nm, respectively. The relative number of micropores increases in the order of SNW-1 < SNW-2 < SNW-3, while the number of mesopores increases in the reverse order. N2 adsorption/desorption measurements also reveal micropores and mesopores in these materials. However, it gives an underestimation of the micropore volume. Benefiting from the abundant nitrogen content and high microporosity, the SNW materials exhibit exceptionally high CO2 capture ability, which reaches a maximum value of 18.3 wt % in SNW-3 at 273 K and 1 bar, followed by SNW-2 and SNW-1. This order is exactly the same as the order of micropore volume revealed by positron annihilation measurement, suggesting that micropores play a crucial role in the CO2 uptake. Our results show that positron can provide more precise information about the structure of micropores and thus can offer an accurate prediction for the adsorption capacity of complex porous materials.
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DOI
高影响因子
CARBON
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2019
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IF 7.466
Ruilong Cai,Bo You,Min Chen,Limin Wu
N-doped carbon/carbon heterojunction holds huge potential for efficient CO 2 capture. Here, a series of site-specific N-doped core-shell carbon spheres with carbon/carbon heterojunction were successfully prepared by carbonization of polypyrrole coated hypercrosslinked polystyrene spheres, followed by chemical activation with KOH. These activated carbon spheres possessed large specific surface area (2080 m 2 g −1 ) and abundant micropores (0.45 cm 3 g −1 ). Despite their low nitrogen content (0.96 wt%), the CO 2 adsorption capacities of activated samples reached 3.69 and 5.80 mmol g −1 measured at 298 and 273 K, respectively, under atmospheric pressure (1 bar). More significantly, the N-doped carbon/carbon heterojunction contributes to a stronger and denser CO 2 packing in this system.
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高影响因子
JOURNAL OF SUPERCRITICAL FLUIDS
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2014
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IF 2.571
Abdul-Rauf Ibrahim,Lihua Zhu,Jing Xu,Yanzhen Hong,Yuzhong Su,Hongtao Wang,Binghui Chen,Jun Li
A CO 2 expanded carbonation technique is proposed for direct synthesis of alumina powders that does not require structure directing substances or templates. Mesoporous amorphous flower-like alumina was synthesized at relatively low volume expansions (lower ethanol to water volume ratio), whereas mesoporous crystalline honey-comb-like alumina was synthesized at high volume expansions. The alumina powders exhibited high surface area and pore size with small crystallite sizes. The alumina structures were stable from 400 to 800 °C. Experimental tests showed that the alumina powders could catalytically convert cyclohexanone to ɛ-caprolactone efficiently. The use of the calcined catalysts (at 400 and 800 °C; flower-like alumina) at equal ethanol to water volume ratio avoids the usual and inevitable hydrolysis of ɛ-caprolactone to ɛ-hydroxyhexanoic acid. The catalyst was recyclable and stable for up to five reaction cycles.
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高影响因子
CARBOHYDRATE POLYMERS
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2016
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IF 4.219
Jisheng Yang,Hongbiao Dong
A new kind of hexyl diethyl tertiary amine-grafted amphiphilic alginate derivative (HDEA-Alg) was synthesized from (6-bromo-hexyl)-diethyl-amine (BHDEA) and sodium alginate (NaAlg) through esterification. The structure of HDEA-Alg was confirmed by FT-IR and NMR spectroscopies. The grafting ratio was calculated according elemental analysis and thermodynamic property was analyzed by TG. The CO 2 /N 2 -responsive performance of HDEA-Alg in aqueous solution was demonstrated by surface tension and conductivity measurements. Stable emulsions of liquid paraffin were easily prepared in the presence of the HDEA-Alg. These emulsions can be de-emulsified by bubbling CO 2 through the emulsions at 5 °C for 30 min, resulting in complete oil/water phase separations. They can be re-emulsified by bubbling N 2 through the solutions at 50 °C for 30 min with the aid of homogenization.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2015
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IF 4.321
Yingchao Hu,Wenqiang Liu,Jian Sun,Mingkui Li,Xinwei Yang,Yang Zhang,Minghou Xu
A novel inert solid support of Nd 2 O 3 was introduced to enhance the cyclic carbonation/calcination performance of CaO-based sorbents. CaO particles were incorporated into Nd 2 O 3 by a wet-mixing method, using three organometallic precursors (OMPs) as calcium precursors and neodymium(III) acetate hydrate as inert support precursor. For comparison, CaO-based sorbents directly produced from precursors and the naturally occurring sorbent (limestone) were also investigated. FSEM and EDAX results revealed that the ultrafine active specie of CaO particles were homogeneously dispersed into Nd 2 O 3 inert support. As a result, an improved durability and higher carbonation conversion were observed owing to the retarded sintering and the delayed diffusion controlled stage respectively for the sorbents investigated. The performance of the synthetic sorbents also relies on the precursor. When calcium dl -lactate pentahydrate (CaL) was used to incorporate CaO into the inert support Nd 2 O 3 , the highest conversion and best durability were obtained. The effect of calcination temperatures on the sorbent durability was also investigated. Under a relatively severe calcination temperature of 900 °C, a high conversion of about 67% were obtained after 100 carbonation/calcination cycles for a sorbent synthesized from calcium dl -lactate pentahydrate (CaL) and neodymium(III) acetate hydrate. When the calcination temperature was changed to a mild one of 800 °C, a significantly high conversion (>92.5%) was maintained over 100 carbonation/calcination cycles. Besides, no apparent capacity decline was observed for the sorbents after granulation.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2022
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IF 9.136
Fan Liu,Yao Shen,Li Shen,Yuchi Zhang,Weiqi Chen,Xiaoxiang Wang,Qiaoli Wang,Sujing Li,Shihan Zhang,Wei Li
The main disadvantage of commercial absorption solution for CO 2 capture from flue gas is extensive energy consumption. A novel amino-functionalized ionic liquid (AFIL) organic solution of tetraethylene pentamine 2-methylimidazolium/N-propanol/ethylene glycol ([TEPAH][2-MI]/NPA/EG) is considered as a promising candidate absorption system because of its efficient CO 2 capture performance and low energy consumption. The thermodynamics and kinetics studies are very essential for evaluating the absorbent and its potential of future practical industrial application. In this work, the performance in these two aspects of [TEPAH][2-MI]/NPA/EG solution were investigated. The regeneration energy consumption was 2.98 GJ·t −1 CO 2 , which was 21.6% lower than that of benchmark monoethanolamine (MEA) aqueous solution, and the energy saving advantage was embodied in sensible heat and latent heat. Kinetic analysis showed that chemical reaction of CO 2 absorption into [TEPAH][2-MI]/NPA/EG solution took place in the pseudo-first-order reaction. The reaction rate constant and enhancement factor increased with the increase of absorption temperature, while those showed a decreasing trend with the increase of absorption loading. The relation between the second-order rate constant and temperature was expressed as k 2 = 5.6192 × 10 8 exp - 3111.6 T , and the activation energy was further calculated as 25.87 kJ·mol −1 . Compared with those of MEA and several traditional ionic liquid solutions, these parameters indicated a stronger reaction ability of the novel system. Moreover, the mass transfer resistance of gas and liquid phase changed constantly during the absorption process, and the dominant role of mass transfer resistance gradually changed from the gas phase to liquid phase. The thermodynamics and kinetics of CO 2 capture revealed that the [TEPAH][2-MI]/NPA/EG solution had an excellent application potential in the future.
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高影响因子
CHINESE JOURNAL OF CATALYSIS
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2022
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IF 12.92
Anxiang Guan,Yueli Quan,Yangshen Chen,Zhengzheng Liu,Junbo Zhang,Miao Kan,Quan Zhang,Haoliang Huang,Linping Qian,Linjuan Zhang,Gengfeng Zheng
The electrocarboxylation reaction is an attractive means to convert CO 2 into valuable chemicals under ambient conditions, while it still suffers from low efficiency due to the high stability of CO 2 . In this work, we report a double activation strategy for simultaneously activating CO 2 and acetophenone by silver-doped CeO 2 (Ag-CeO 2 ) nanowires, featuring as an effective electrocatalyst for electrocarboxylation of acetophenone with CO 2 . Compared to the Ag foil, Ag nanoparticles and CeO 2 nanowires, the Ag-CeO 2 nanowire catalyst allowed to reduce the onset potential difference between CO 2 and acetophenone activation, thus enabling efficient electrocarboxylation to form 2-phenyllactic acid. The Faradaic efficiency for producing 2-phenyllactic acid reached 91% at −1.8 V versus Ag/AgI. This double activation strategy of activating both CO 2 and organic substrate molecules can benefit the catalyst design to improve activities and selectivities in upgrading CO 2 fixation for higher-value electrocarboxylation.
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DOI
高影响因子
ACS Omega
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2022
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IF 4.132
Lisha Sheng,Zhenqian Chen,Xin Wang,Abdul Samad Farooq
Porous liquids (PLs) have both liquid fluidity and solid porosity, thereby offering a variety of applications, such as gas sorption and separation, homogeneous catalysis, energy storage, and so forth. In this research, canopies with varying structures were utilized to modify porous silica nanoparticles to develop Type I PLs. According to experimental results, the molecular weight of canopies should be high enough to maintain the porous materials in the liquid state at room temperature. Characterization results revealed that PL_1_M2070 and PL_1_AC1815 displayed low viscosity and good fluidity. Both low temperature and high pressure positively influenced CO2 capacity. The cavity occupancy resulted in poorer sorption capacity of PLs with branched canopies in comparison with that with linear canopies. Furthermore, the sorption capacity of PL_1_M2070 was 90.5% of the original CO2 sorption capacity after 10 sorption/desorption cycles, indicating excellent recyclability.
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DOI
高影响因子
Journal of Cleaner Production
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2024
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IF 9.7
Song Xiao,Menglei Jin,Junyi Chen,Peng Wu,Ju Tang,Yi Luo,Yi Li
Perfluoroisobutyronitrile (C 4 F 7 N) mixed with CO 2 has emerged as a promising eco-friendly alternative to sulfur hexafluoride (SF 6 ) in gas-insulated equipment (GIE). However, thermal or discharge faults in GIE inevitably lead to the generation of harmful decomposition by-products, necessitating their prompt removal to safeguard equipment operation and personnel safety. In this study, we propose a nanofiber composite material comprising polyacrylonitrile (PAN) as the base and multi-metal organic frameworks (MOFs) as the primary adsorbent material for removing typical decomposition components of C 4 F 7 N/CO 2 gas mixture. Utilizing grand canonical Monte Carlo (GCMC) and molecular dynamics (MD) simulations, we elucidate the selective adsorption mechanisms. Experimental results show that PAN@HKUST-1(Cu) exhibits superior adsorption efficiency for fluorocarbon gases compared to PAN@MIL-101(Cr), while the latter demonstrates better performance for nitrile gases. The PAN@HKUST-1(Cu)/MIL-101(Cr) composite adsorbent effectively removes eight typical harmful decomposition products while minimally affecting C 4 F 7 N. Our findings suggest that PAN@HKUST-1(Cu)/MIL-101(Cr) nanofiber film holds promise as an adsorbent for C 4 F 7 N/CO 2 based GIE.
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Min Zhang,Shipeng Zeng,Zhihong Du,Hailei Zhao
A new series of layered perovskite K 2 NiF 4 structure La 2 Ni 1-x Sb x O 4+δ (LNSx, x = 0, 0.025, 0.05) were used to prepare the LNSx-molten carbonate (MC) dual-phase membrane for CO 2 separation. Sb doping at the Ni site is expected to enhance CO 2 permeability and improve the resistance towards CO 2 /carbonate corrosion. In this work, the CO 2 permeability of the LNSx- MC membrane was investigated for CO 2 -containing atmospheres with and without oxygen, and correlated with the lattice characteristics, microstructure, chemical bond, and conductivity of LNSx support. The result shows that the introduction of Sb improves the structure symmetry and increases the interstitial oxygen concentration, which is beneficial for oxygen ion transport. The superior CO 2 permeability of Sb-doped sample is confirmed by the higher permeation fluxes with value of 0.15 mL min −1 cm −2 at 800 °C of LNS0.025-MC dual-phase membrane in 50% CO 2 + 50% N 2 . In addition, the LNS0.025-MC dual-phase membrane achieves a great enhancement in chemical and structural stability compared to the LNS0. In the simulated flue gas 15% CO 2 + 10% O 2 + 75% N 2 , the LNS0.05-based dual phase membrane shows a high permeation flux of 1.07 mL min −1 cm −2 at 800 °C, which is 2 times higher than that of LNS0-based dual-phase membrane.
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DOI
高影响因子
APPLIED SURFACE SCIENCE
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2022
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IF 7.392
Chunling Li,Zhikun Wang,Wendong Wang,Huafeng Zhu,Shuangqing Sun,Songqing Hu
Synergism has developed to be an important means to improve the foaming, stabilizing and responsive deforming characteristics of foam. Here, CO 2 /N 2 responsive surfactants with tunable lengths of carbon chains are synthesized. Through forming and deforming testing, the obtained 11-dimethylamino-undecyl sulfate sodium (11-DUSNa) with 11 carbons on the linear tail chain has the best comprehensive performance. 11-DUSNa is then mixed with Cocamidopropyl Hydroxyl Sulfobetaine (CHSB) to produce a compound foam with enhanced temperature and salt tolerance. Experimental observations show that the compound foam has the largest stability by adding 3.2 mol/L divalent salts (Ca 2+ , Mg 2+ ), and has improved temperature resistance from 20 to 100 °C compared to singular surfactant foam. The compound foam defoams in response to the injection of CO 2 within 2200 s. The foaming and defoaming processes can be cycled many times by repeat addition of NaOH for deprotonation and CO 2 for protonation of amino groups. Molecular dynamics simulations show that Ca 2+ and Mg 2+ cations distributing around the head groups of surfactants form a stable network liquid film wall, explaining why the compound foam is salt tolerant. The synergistic effect of CHSB and anions increases the liquid film wall thickness and therefore leads to better temperature resistance.
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DOI
高影响因子
Gas Science and Engineering
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2023
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IF 0
Rui Zhang,Haonan Liu,Ruixi Liu,Yingjie Niu,Luning Yang,Francesco Barzagli,Chao'en Li,Min Xiao
The blending of primary amines, with fast reaction kinetic, together with tertiary amines, with a large loading capacity, is an increasingly popular approach to develop high-performance CO 2 capture sorbents with low energy requirements for regeneration. In this study, we investigated the CO 2 absorption performance of several aqueous solutions obtained by mixing ethanolamine (MEA) and diethylethanolamine (DEEA) and compared them with that of individual MEA and DEEA. CO 2 loadings at equilibrium were measured experimentally under a wide range of operating conditions, at temperatures between 298 and 323 K, CO 2 partial pressures in the range 5–60 kPa, and different amine mixing ratios. In addition, 13 C NMR spectroscopy was employed to elucidate the reaction mechanisms and identify the species formed during CO 2 capture. The results of the study reveal the intricate interplay of MEA and DEEA in CO 2 capture, where MEA carbamate formation predominates in the early stages, gradually shifting to bicarbonate formation as the amine concentration decreases. Moreover, excess properties, which reflect non-ideal behaviors in amine blends, were introduced as a key parameter in the study. An excess property model, based on excess CO 2 loading, was developed to accurately predict the CO 2 equilibrium solubility without constant experimental measurement. As a result, good agreement was found between the experimental data and those calculated with the model (excess CO 2 loading) under the same operating conditions, with a average relative deviation of 1.1%.
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