CHEMICAL ENGINEERING JOURNAL
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2019
·
IF 8.355
Tianqi Zhang,Jian Yin,Ying Pan,Enhua Liu,Dongxia Liu,Jianqiang Meng
Synthesis of cyclic carbonates via cycloaddition of CO 2 to epoxides is an important strategy for CO 2 valorization. However, efficient and easy-to-handle catalytic system for this type of reaction at mild conditions is still rare. In this work, we present a polyimide-based catalytic membrane with hierarchical pore structure for flow through synthesis of cyclic carbonates at mild conditions. The membrane was fabricated by incorporating a porous and metallized poly-melamine-formaldehyde (Zn@PMF) into phase inversed polyimide (PI) matrix. Upon in-situ crosslinking with tris(2-aminoethyl)amine, the solvent-resistant PI membrane can not only facilitate the CO 2 adsorption and immobilize the catalysts, but also promote mixing by flow-through operations. As a result, the nanocomposite membrane exhibited an excellent catalytic performance with a maximum TOF value of 3362 h −1 at ambient conditions. This catalytic activity is not only higher than the Zn@PMF particle but also is the highest among reported catalysts under the similar reaction conditions. Its high catalytic performance was also confirmed in CO 2 cycloaddition in a synthetic flue gas stream.
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APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Huiqin Wang,Jingru Guan,Jinze Li,Xin Li,Changchang Ma,Pengwei Huo,Yongsheng Yan
In this work, the ordered mesoporous CeO 2 (m-CeO 2 ) was successfully fabricated via the nanocasting pathway, through using SBA-15 as a hard template. Besides, g-C 3 N 4 /Ag/m-CeO 2 composite was successfully constructed by calcination method. Meanwhile, the obtained samples were investigated by series of test techniques. The XRD, SEM and TEM results show that the m-CeO 2 and Ag/m-CeO 2 with the ordered mesoporous trait. Besides, the EPR, Raman and XPS results suggest that the oxygen vacancies (O v ) and Ce 3+ and Ce 4+ are in g-C 3 N 4 /Ag/m-CeO 2 . In addition, the ordered mesostructure is favorable for the CO 2 molecular movement and adsorption/desorption reaction. The g-C 3 N 4 nanosheets, a promising material possessing suitable conductor band, large specific area, non-toxicity, and outstanding chemical stability, is a candidate semiconductor for CO 2 conversion. The introduction of g-C 3 N 4 nanosheets to Ag/m-CeO 2 overcomes the photocorrosion of Ag nanoparticles and Ag facilitate the transfer of photogenerated electrons. The photocatalytic activity results show that when the loading of Ag is 7 wt%, the g-C 3 N 4 /7Ag/m-CeO 2 composite exhibits the superiority activity for CO 2 photoconversion to CO (13.94 μmol/g) and CH 4 (7.39 μmol/g) under UV-irradiation in 10 h.
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JOURNAL OF FOOD PROCESSING AND PRESERVATION
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2018
·Vol. 42
·期 7
·e13665
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IF 1.51
Jia Liu,Liping Qiao,Xiaolin Ren,Xihong Li
Persimmons are popular worldwide owning to their unique flavor and nutritional value, while for the astringent cultivars, deastringency treatment is needed before processing. The current deastringency methods are limited to CO 2 and ethanol. The aim of this work was to select optimal deastringency methods and assess the bioavailability of polyphenols in persimmon peels treated with 12 different combination of CO 2 and ethanol. The level of soluble and insoluble tannins, total polyphenols bioaccessibility, antioxidant properties, color, and soluble solids were also determined. Results indicated that soluble tannin contents decreased with increasing ethanol concentration, and with an increase in carbon dioxide concentration, the insoluble tannins content increased. Application of 30% ethanol solution and 80% carbon dioxide for 24 hr has a best deastringency effect, while this treatment does not show good phenolics bioaccessibility and antioxidant activity. Therefore, the combination of 30% ethanol solution with 70% CO 2 fumigation for 24 hr at 10 °C is the best deastringency method. Practical applications This project invented a novel deastringency method by CO 2 and ethanol combination, with a feature of applying to lower temperature. The aim of this work was to select optimal deastringency methods and assess the bioavailability of polyphenols in persimmon peels treated with 12 different combination of CO 2 and ethanol.
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ACS Applied Materials & Interfaces
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2018
·
IF 8.097
Hongjie Cui,Qiming Zhang,Yuanwu Hu,Chong Peng,Xiangchen Fang,Zhenmin Cheng,Vladimir V. Galvita,Zhiming Zhou
As a potential candidate for precombustion CO2 capture at intermediate temperatures (200–400 °C), MgO-based sorbents usually suffer from low kinetics and poor cyclic stability. Herein, a general and facile approach is proposed for the fabrication of high-performance MgO-based sorbents via incorporation of CaCO3 into MgO followed by deposition of a mixed alkali metal salt (AMS). The AMS-promoted MgO–CaCO3 sorbents are capable of adsorbing CO2 at an ultrafast rate, high capacity, and good stability. The CO2 uptake of sorbent can reach as high as above 0.5 gCO2 gsorbent–1 after only 5 min of sorption at 350 °C, accounting for vast majority of the total uptake. In addition, the sorbents are very stable even under severe but more realistic conditions (desorption in CO2 at 500 °C), where the CO2 uptake of the best sorbent is stabilized at 0.58 gCO2 gsorbent–1 in 20 consecutive cycles. The excellent CO2 capture performance of the sorbent is mainly due to the promoting effect of molten AMS, the rapid formation of CaMg(CO3)2, and the plate-like structure of sorbent. The exceptional ultrafast rate and the good stability of the AMS-promoted MgO–CaCO3 sorbents promise high potential for practical applications, such as precombustion CO2 capture from integrated gasification combined cycle plants and sorption-enhanced water gas shift process.
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高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2018
·
IF 2.196
Xiaofeng Li,Xiaobang Liu,Dongshun Deng
The solubility data of CO2 in four azole-based deep eutectic solvents (DESs), prepared from azoles (imidazole, Im; 1,2,4-triazole,Tri) and acetylcholine chloride (ACC), were reported at temperatures of 303.15, 313.15, 323.15, and 333.15 K under a pressure range of (20.0- 600.0) kPa using the isochoric saturation method. Henry’s constants and thermodynamic properties of standard Gibbs free energy, enthalpy, and entropy changes of CO2 dissolution were derived by correlating the data. Results demonstrated that ACC-Im DESs (Hm = 1.91–4.46 MPa·kg·mol–1) possess higher capacities of CO2 than CC-Tri ones (Hm = 2.66- 4.58 MPa·kg·mol–1). The CO2 solubility increased with rising pressure, mole ratio of Im to ACC, and decreasing temperature. All the obtained enthalpies of solution were negative. Furthermore, the comparison of dissolution capacities between present DESs and other DESs as well as some ionic liquids in the literature was conducted.
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AICHE JOURNAL
·
2018
·Vol. 64
·期 9
·3400-3409
·
IF 3.326
Weixin Zhang,Dahuan Liu,Xiangyu Guo,Hongliang Huang,Chongli Zhong
Mixed-matrix membranes (MMMs) have shown great advantages but still face some challenges, such as the trade-off between permeability and selectivity, stability, and the lack of efficient ways to enhance them simultaneously. Here, the fabrication of MMMs with metal-organic frameworks derived porous carbons (MOF-PCs) as fillers which exhibit selective-facilitating CO 2 transport passage originating from interactions between fillers and CO 2 is showed. With the aid of the developed multicalcination method, MOF-PCs with variable N-contents were prepared and incorporated into PPO-PEG matrix for the first time to prepare MMMs, which show excellent separation performance for CO 2 /CH 4 mixture with a tunable separation performance by combining different N-contents and surface areas of MOF-PCs. Moreover, the developed MMMs have hydrothermal and chemical stability. This work not only presents a series of MMMs with both good separation properties and stability, it also provides useful information for guiding the fabrication of high performance MMMs for practical application. © 2018 American Institute of Chemical Engineers AIChE J , 64: 3400–3409, 2018
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ENERGY & FUELS
·
2018
·
IF 3.024
Yannan Li,Jun Cheng,Leiqing Hu,Jianzhong Liu,Junhu Zhou,Kefa Cen
An ionic liquid (IL) [P66614][Triz] with a low regeneration temperature was loaded on a graphene nanoplatelet (GNP) and reduced graphene oxide (RGO) to accelerate the CO2 absorption rate. High-resolution transmission electron microscopy (HRTEM) patterns showed that GNP was composed of a regular “honeycomb” lattice, but a regular lattice structure was not observed for RGO as a result of the functional group on it. The CO2 absorption capacity (63.6 mg of CO2/g of IL) and absorption peak rate (22.4 mg of CO2 g–1 of IL min–1) of IL loaded on GNP were increased by 8.2 and 72.3%, respectively, compared to those of neat IL. The supported IL performed better because [P66614][Triz] was oriented in a favorable dispersion as a result of the negative ζ potential of the GNP surface. In contrast, the CO2 absorption rate of RGO–20% IL (mass ratio of RGO/IL = 4:1) was lower than that of IL, which could be attributed to the hydrogen bond between surface oxygen functional groups and IL. 13C nuclear magnetic resonance and Mulliken atomic charge calculated by Gaussian were used to support the CO2 absorption mechanism.
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ENERGY & FUELS
·
2018
·
IF 3.024
Yafei Guo,Chang Tan,Jian Sun,Weiling Li,Chuanwen Zhao,Jubing Zhang,Ping Lu
Nanostructured MgO sorbents show promise for intermediate-temperature CO2 capture from post-combustion flue gas stream. However, their CO2 capture behaviors can be affected by the magnesium precursors applied for sorbent synthesis. To screen potential precursors for fabricating excellent CO2 trappers, MgO nanoparticles (NPs) were synthesized by calcining several organometallic precursors, including magnesium ethoxide, magnesium acetate tetrahydrate, magnesium oxalate dehydrate, magnesium lactate dihydrate, magnesium citrate nonahydrate, and magnesium gluconate hydrate. The precursors and MgO NPs were characterized by thermogravimetric analysis, X-ray diffraction, N2 adsorption–desorption, field emission scanning electron microscopy, and CO2 temperature-programmed desorption. A fixed-bed reactor was used to evaluate the CO2 capture performances of the MgO NPs in a simulated flue gas stream. The effect of organometallic precursors on CO2 capture behaviors of the sorbents was further demonstrated. Results indicated that the different precursors would yield MgO NPs with distinct textural and surface properties, and these could further affect their CO2 capture behaviors. MgO NPs derived from magnesium oxalate dehydrate exhibited the highest CO2 uptake of 4.41 mmol of CO2/g. The excellent CO2 uptake was mainly attributed to its superlative textural properties, uniform surface morphology, and abundant base sites.
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JOURNAL OF MEMBRANE SCIENCE
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2018
·
IF 6.578
Rui Xu,Zhi Wang,Ming Wang,Zhihua Qiao,Jixiao Wang
Under high nanoparticles loadings, the gas separation performance mixed matrix membranes (MMMs) could be limited by the inferior compatibility between polymer and nanoparticles. Herein, we utilized a “bridging-crosslinking” method to connect the polymer and nanoparticles via macromolecule. Specially, the poly(vinylamine) (PVAm) and UIO-66-NH 2 nanoparticles were bridging-crosslinked by using poly(ethylene glycol) diglycidyl ether (PEGDE) to achieve high nanoparticles loadings. By this way, even though the nanoparticles loadings attained 28.5 wt%, the incorporated nanoparticles still showed good dispersion in coating solution without sedimentation for one week. According to the gas permeation test, the fabricated MMMs with amounts of functional groups via “bridging-crosslinking” method displayed excellent gas separation performance and good long-term stability under the simulated flue gas . For CO 2 /N 2 (15/85) mixed gas, the MMMs can achieve a high CO 2 permeance of 1295 GPU and CO 2 / N 2 selectivity of 91 at 0.3 MPa. For CO 2 /CH 4 (10/90) mixed gas and CO 2 /H 2 (40/60) mixed gas, the gas separation performance of MMMs was investigated.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2018
·
IF 5.091
Yahui Sun,Kaixi Li,Jianghong Zhao,Jianlong Wang,Nan Tang,Dongdong Zhang,Taotao Guan,Zuer Jin
Millimeter-sized nitrogen and sulfur co-doped microporous activated carbon spheres (NSCSs) were first synthesized from poly(styrene-vinylimidazole-divinylbenzene) resin spheres through concentrated H 2 SO 4 sulfonation, carbonization and KOH activation. Styrene (ST) and N-vinylimidazole (VIM) were carbon and nitrogen sources, while the sulfonic acid functional groups introduced by the simple concentrated sulfuric acid sulfonation worked simultaneously as cross-linking agent and sulfur source during the following thermal treatments. It was found that the surface chemistries, textural structures, and CO 2 adsorption performances of the NSCSs were significantly affected by the addition of VIM. The NSCS-4-700 sample with a molar ratio of ST: VIM = 1: 0.75 showed the best CO 2 uptake at different temperatures and pressures. An exhaustive adsorption evaluation indicated that CO 2 sorption at low pressures originated from the synergistic effect of surface chemistry and micropores below 8.04 Å, while at the moderate pressure of 8.0 bar, CO 2 uptake was dominated by the volume of micropores. The thermodynamics suggested the exothermic and orderly nature of the adsorption process , which was dominated by a physisorption mechanism. The high CO 2 adsorption capacity, fast kinetic adsorption rate, and great regeneration stability of the nitrogen and sulfur co-doped activated carbon spheres indicated that the as-prepared carbon adsorbents were good candidates for large-scale CO 2 capture.
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高影响因子
Nanomaterials
·
2018
·Vol. 8
·期 5
·275
·
IF 3.504
Jingting Lu,Chengli Jiao,Zeeshan Majeed,Heqing Jiang
Mesoporous carbons (MC) have attracted a tremendous amount of interest due to their efficient molecular transport properties. However, the limited number of active sites and low microporosity generally impede their use for practical applications. Herein, we have fabricated Mg and N co-doped mesoporous carbon (Mg-NMC) with high microporosity via one-pot synthetic route followed by further steam activation. In comparison with the parent N-doped mesoporous carbon, Mg-NMC shows partially ordered mesostructure and improved CO2adsorption capacity attributed to the introduction of basic site after Mg doping. Upon further steam activation, the microporosity is enhanced to 37.3%, while the CO2adsorption capacity is also increased by 70.4% at 273 K and 1.0 bar.Keywords:mesoporous carbon;Mg doping;steam activation;basic site;microporosity;CO2adsorption
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ACS Catalysis
·
2018
·
IF 11.384
Min Zhou,Sibo Wang,Pengju Yang,Caijin Huang,Xinchen Wang
Ternary boron carbon nitride (BCN) semiconductors have been developed as emerging metal-free photocatalysts for visible-light reduction of CO2, but the achieved efficiency is still not satisfying. Herein, we report that the CO2 photoreduction performance of a bulk BCN semiconductor can be substantially improved by surface engineering with CdS nanoparticles. The CdS/BCN photocatalysts are characterized completely by diverse tests (e.g., XRD, FTIR, XPS, DRS, SEM, TEM, N2 sorption, PL, and transient photocurrent spectroscopy). Performance of the CdS/BCN heterostructures is evaluated by reductive CO2 conversion reactions with visible light under benign reaction conditions. Compared with bare BCN material, the optimized CdS/BCN photocatalyst exhibits a 10-fold-enhanced CO2 reduction activity and high stability, delivering a considerable CO production rate of 12.5 μmol h–1 (250 μmol h–1 g–1) with triethanolamine (TEOA) as the reducing agent. The reinforced photocatalytic CO2 reduction activity is mainly assigned to the obviously improved visible-light harvesting and the greatly accelerated separation/transport kinetics of light-triggered electron–hole pairs. Furthermore, a possible visible-light-induced CO2 reduction mechanism is proposed on the basis of photocatalytic and photo(electro)chemical results.
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