JOURNAL OF MEMBRANE SCIENCE
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2020
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IF 7.183
Songlin Dong,Zhi Wang,Menglong Sheng,Zhihua Qiao,Jixiao Wang
Preparation of CO 2 separation membrane with high gas permeance and CO 2 selectivity is always desirable. In this work, inspired by pesticides and cosmetics, through the use of a variety of additives, good compatibility between the water-based coating solution of low concentration and the hydrophobic surface of the intermediate layer (or gutter layer) had been achieved. A membrane with high gas permeance and moderate CO 2 selectivity was prepared preliminarily, and the synergistic mechanism among various additives was clarified. Then, through simple cross-linking modification of the membrane surface, a multi-layer composite membrane for CO 2 separation was prepared with CO 2 selectivity being improved greatly. The degree of cross-linking on the membrane surface and the thickness of the cross-linked layer was studied by XPS etching analysis. Separation performance for CO 2 /N 2 , CO 2 /CH 4 , and CO 2 /H 2 mixture had been tested, and the prepared multi-layer composite membrane exhibited excellent CO 2 separation performance. Moreover, the simulated flue gas test showed that the prepared membrane was of good long-term stability and impurity resistance.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2020
·
IF 10.652
Ruijie Xie,Jianping Cao,Xiaowen Xie,Dongxue Lei,Kaiheng Guo,Hong Liu,Yuxuan Zeng,Haibao Huang
Chlorobenzene is a typical chlorinated volatile organic compound (CVOC), and the degradation of chlorobenzene frequently produces high-toxic byproducts such as dioxins in the treatment process. To prevent this, complete oxidation of chlorobenzene into harmless CO 2 is highly desirable. Wet scrubber coupled with advanced oxidation processes (AOPs) for gaseous VOCs treatment has been widely reported, but their mineralization capacity and mechanism are still poorly understood. Herein, this study developed an efficient technology for chlorobenzene oxidation via wet scrubbing process coupled with UV/peroxydisulfate (PDS), with UV/H 2 O 2 as comparison. The mineralization efficiency of chlorobenzene was much higher in UV/PDS (75.4%) than that in UV/H 2 O 2 (42.0%), although the removal efficiencies in both AOPs were similar at 90–97%. Sulfate radical (SO 4 •− ) was predominant for the initial oxidation of chlorobenzene, forming the intermediates that were favorable for the mineralization process. Then, O 2 and HO • played important roles on the formation of CO 2 in the complete oxidation of chlorobenzene in UV/PDS. The role of O 2 was further comfirmed by the result that high-toxic dimeric products, rather than CO 2 , were generated in UV/PDS in the absence of O 2 . The possible pathway on chlorobenzene oxidation was proposed based on the evolution of intermediates and Density Functional Theory (DFT) calculation. Carbon cation radical was formed from the initial oxidation of chlorobenzene by SO 4 •− , followed by the ring-opening and more CO 2 yields via the synergetic effect of SO 4 •− , O 2 and HO • . This study not only provides an environment-friendly method to improve the VOC removal efficiency, but also gets a deep understanding of the different functions of SO 4 •− , HO • and O 2 on the mineralization process.
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高影响因子
FUEL
·
2020
·
IF 5.578
Chufei Lv,Leilei Xu,Mindong Chen,Yan Cui,Xueying Wen,Cai-e Wu,Bo Yang,Fagen Wang,Zhichao Miao,Xun Hu,Qinghui Shou
In this work, we reported that the fibrous silica nanosphere, also called as KCC-1, was facilely synthesized by the improved microemulsion hydrothermal fabrication strategy. The obtained KCC-1 was investigated as the support of the Ni based catalysts toward CO 2 methanation. The obtained catalysts with unique dendrimeric mesopore structure and outstanding structural properties could provide easily accessible as well as highly dispersed Ni nanoparticles to the gaseous reactants. Besides, the Ni based catalysts with commercial SiO 2 and MCM-41 as supports were also prepared as the reference catalysts to demonstrate the advantages of the dendrimeric mesoporous channels. Various techniques, such as X-ray powder diffraction (XRD), N 2 physisorption, transmission electron microscopy (TEM), H 2 temperature programmed reduction (H 2 -TPR), CO 2 temperature programmed desorption (CO 2 -TPD), X-ray photoelectron spectroscopy (XPS), etc., were used to characterize the catalytic supports and corresponding catalysts. It was found that the metallic Ni nanoparticles could be highly dispersed over the catalysts supported on fibrous KCC-1 with dendrimeric mesoporous channels. Furthermore, the catalytic performances toward CO 2 methanation had been further evaluated over these catalysts at different temperatures. It was found that the KCC-1 supported catalyst performed much higher low-temperature catalytic activities than the reference catalysts supported on commercial SiO 2 and MCM-41, suggesting that the fibrous and dendrimeric mesoporous channels displayed distinctive advantages by accommodating enough metallic Ni active sites. The kinetic study also revealed that the topology of the mesoporous channel could obviously influence the apparent activation energy in the CO 2 methanation reaction. Besides, the temperature programmed surface reaction (TPSR) and in-situ Diffused Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) of the CO 2 methanation were also carried out to reveal the possible reaction pathway and mechanism. We also found that the fibrous silica nanosphere (KCC-1) supported catalyst demonstrated much better sintering-proof property of the metallic Ni nanoparticles than the reference catalysts during the 40 h stability tests at 400 °C. Therefore, the present fibrous silica nanosphere (KCC-1) could be considered as the promising support for Ni based catalysts toward CO 2 methanation.
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高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
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IF 3.573
Tengjiao He,Yonghou Xiao,Qidong Zhao,Mengxue Zhou,Gaohong He
Separation of carbon dioxide (CO2) from a CO2/ethylene (C2H4) mixture represents an important and challenging field in industrial applications. Selective adsorption has become an attractive option as an energy-saving and environmentally friendly CO2 capture technology. In this work, an ultramicroporous metal–organic framework (MOF) Qc-5-Cu was prepared by solution method and applied for the highly selective separation of CO2 from an C2H4 stream. The performance of Qc-5-Cu was evaluated by static and dynamic adsorption experiments. It was found that the single-component adsorption capacities of CO2 and C2H4 on Qc-5-Cu at 298 K and 1 bar were 2.48 and 0.74 mmol/g, respectively. The measured breakthrough curves further illustrate that Qc-5-Cu could effectively separate CO2 from the C2H4 stream for more than 10 cycles. The pore size of the obtained Qc-5-Cu was ∼3.3 Å, as characterized by nitrogen adsorption. The ultramicroporous structure of Qc-5-Cu benefits the separation of CO2, as evidenced by the selectivity values of the CO2/C2H4 binary mixture (1:99, v/v) based on the ideal adsorbed solution theory (SIAST ≈ 39.95 avg.), which are larger than some MOFs with open metal sites, owing to the weak interaction between organic ligands with high aromaticity and C2H4, as well as the porous screening effect of Qc-5-Cu on ethylene. The observed high selectivity, excellent stability, and regeneration performance demonstrate that Qc-5-Cu is a promising adsorbent for the separation of the CO2/C2H4 mixture.
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高影响因子
FUEL PROCESSING TECHNOLOGY
·
2021
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IF 7.033
Shuzhen Chen,Changlei Qin,Weiyang Yuan,Dawid P. Hanak,Jingyu Ran
Li 4 SiO 4 is acknowledged as a promising sorbent candidate in high-temperature CO 2 adsorption. However, reaction kinetics for the regeneration process of Li 4 SiO 4 , especially its dependence on CO 2 pressure is lack of understanding. This work designed and carried out a series of isothermal tests on the regeneration of pure Li 4 SiO 4 and K-Li 4 SiO 4 under CO 2 partial pressure of 0–0.5 atm and temperature of 625–725 °C. For the first time, the expression of ( P eq − P CO 2 ) n is introduced into the regeneration rate equation so as to reveal its dependence on CO 2 pressure. The reaction order ( n ) is found to grade according to the value of ( P eq − P CO 2 ), and the apparent activation energy is calculated as 284.42 kJ•mol −1 and 146.31 kJ•mol −1 for the regeneration of Li 4 SiO 4 and K-Li 4 SiO 4 , respectively. Furthermore, this work proposes that power law model with m = 4/3 is the most probable mechanism function for the regeneration of Li 4 SiO 4 -based sorbents.
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高影响因子
Materials Chemistry Frontiers
·
2021
·Vol. 5
·期 16
·6160-6170
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IF 6.482
Xinxin Yang,Chunyu Ren,Xiuxiu Liu,Penghao Sun,Xu Xu,He Liu,Minggui Shen,Shibin Shang,Zhanqian Song
As one of the important reasons for the greenhouse effect, CO2 can be effectively fixed by reacting with epoxides to synthesize the raw material cyclic carbonate of non-isocyanate polyurethanes (NIPUs). Thus, the environmental problems caused by CO2 and toxic isocyanates can be alleviated. Hence, we reported a strategy to use CO2 by preparing bio-based NIPUs using cyclic carbonated soybean oil with amines. The effect of the structure of the NIPUs on their mechanical properties, thermal properties, and dynamic thermomechanical properties was explored. More importantly, stress relaxation was performed to confirm the bond exchange behavior of hydroxyl with carbamate. The mechanical properties of NIPUs after physical hot pressing and chemical degradation recycling can be restored to at least 85% of their original values, indicating excellent reprocessing. The shape of the NIPUs is almost completely recovered, confirming the attractive shape memory. This work reveals an effective method for preparing bio-based NIPUs using the cyclic carbonate obtained by fixing CO2 with epoxy soybean oil; as expected, they exhibit interesting reprocessing and shape memory performance.
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JOURNAL OF MEMBRANE SCIENCE
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2021
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IF 8.742
Tianqi Sun,Wenji Zheng,Jiahong Chen,Yan Dai,Xiangcun Li,Xuehua Ruan,Xiaoming Yan,Gaohong He
The electrospun nanofiber mat (NFM) with 3D networks has advantages of high porosity and large specific surface area, but its porous structure limits the application in gas membrane separation . Therefore, in this work, a novel and defect-free nanofibers interpenetrating composite membrane is proposed for CO 2 /N 2 separation. And it is constructed by in-situ polymerization of low-molecular-weight polyethylene glycol (PEG) into the inner-voids within PAN NFM. In this nanofiber composite membrane (NFCM), PAN nanofibers interpenetrate into PEO matrix to form a “reinforced-concrete” structure with good interfacial compatibility between them, which has been demonstrated by SEM, EDS , ATR-FTIR and C1s XPS characterizations. Particularly, the PAN nanofiber acts as “Rebar” framework, while the void-sealing polymer PEO serves as “Concrete”. They are bonded into a whole through adhesive force to bear the external force together, resulting in elevated mechanical properties than the pure PEO membrane. Furthermore, the CO 2 permeability of each PEO/PAN NFCM shows a minor decease in contrast with corresponding pure PEO membrane due to the barriers of PAN nanofibers to CO 2 molecules. However, the CO 2 /N 2 selectivity of each NFCM has been increased by 13–15 in contrast with its corresponding pure PEO membrane. This enhancement can be explained by the size screening from PAN nanofibers overlapping and stacking and the tortuous transport pathway along the impermeable PAN nanofibers. As a result, the 3:7/PAN NFCM exhibits a CO 2 permeability of 343 Barrer and a CO 2 /N 2 selectivity of 65.4, exceeding the Robeson upper bond of 2008. Together with the excellent mechanical properties, the proposed nanofibers interpenetrating composite membrane displays a bright prospect for CO 2 capture.
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APPLIED CATALYSIS B-ENVIRONMENTAL
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2021
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IF 19.503
Minzhi Ma,Zeai Huang,Dmitry E. Doronkin,Wenjun Fa,Zhiqiang Rao,Yanzhao Zou,Rui Wang,Yunqian Zhong,Yuehan Cao,Ruiyang Zhang,Ying Zhou
Cobalt species as active sites for photocatalytic reduction of CO 2 to valuable products such as methanol have received increasing attention, however, it remains a huge challenge to achieve the high activity. Herein, a pyrolysis-induced-vaporization strategy was successfully employed to fabricate Co/g-C 3 N 4 single-atom catalysts (Co/g-C 3 N 4 SACs) with surface Co atom loading up to 24.6 wt%. Systematic investigation of Co/g-C 3 N 4 SACs formation process disclosed that concentrated-H 2 SO 4 exfoliation of g-C 3 N 4 nanosheets (g-C 3 N 4 NSs) as the substrate followed by a two-step calcination process is essential to achieve ultrahigh metal loading. It was found that the ultrahigh-density of Co single-atom sites were anchored on the g-C 3 N 4 substrate surface and coordinated with two nitrogen and one carbon atoms (Co-N 2 C). These single dispersed Co-N 2 C sites on the g-C 3 N 4 surface were found to act not only as electron gathering centers but also as the sites of CO 2 adsorption and activation, subsequently, boosting the photocatalytic methanol generation during light irradiation. As a result, the methanol formation rate at 4 h (941.9 μmol g −1 ) over Co/g-C 3 N 4 -0.2 SAC with 24.6 wt% surface Co loading was 13.4 and 2.2 times higher than those of g-C 3 N 4 (17.7 μmol g −1 ) and aggregated CoO x /g-C 3 N 4 -0.2 (423.9 μmol g −1 ), respectively. Simultaneously, H 2 (18.9 μmol g −1 h −1 ), CO (2.9 μmol g −1 h −1 ), CH 4 (3.4 μmol g −1 h −1 ), C 2 H 4 (1.1 μmol g −1 h −1 ), C 3 H 6 (1.4 μmol g −1 h −1 ), and CH 3 OCH 3 (3.3 μmol g −1 h −1 ) products were detected over Co/g-C 3 N 4 -0.2 SAC. Besides, the photocatalytic activity of the Co/g-C 3 N 4 -0.2 SAC for the reduction of CO 2 to methanol was stable within 12-cycle experiments (~48 h). This work paves a strategy to boost the photoreduction CO 2 activity via loading ultrahigh surface density single atomically dispersed cobalt active sites.
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高影响因子
CELLULOSE
·
2021
·Vol. 28
·期 16
·10373-10384
·
IF 5.044
Cao Qinghua,Dai Jinyue,Bao Xin,Zhang Zhenyu,Liu Fei,Feng Yuhong,Na Haining,Zhu Jin
Abstract A series of cellulose-based fluorescent materials are prepared under relative mild conditions by use of the DMSO/1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)/CO 2 system to utilize as coating pigments. Through the observation under 365 nm UV light, the cellulose-based fluorescent materials exhibit good fluorescence response and bright color. Furthermore, due to the limitation of the molecular skeleton of cellulose, the intrinsic aggregation caused quenching phenomenon commonly existed in conventional organic fluorescent pigments can be effectively inhibited, which is very helpful to retain good fluorescence response in epoxy-based coating material and its coating films. Moreover, the addition of cellulose-based fluorescent materials also increases the mechanical properties of the coating film. The increase of tensile strength and tensile modulus respectively reaches ~39% and ~66%. Solvent resistance and thermal property of the coating films generally remain unchanged. The fabrication of cellulose-based fluorescent materials in DMSO/DBU/CO 2 system provides a feasible way to develop the functional application of cellulose. Graphic abstract
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高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2021
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IF 8.128
Ahmed Mahmoud Idris,Xinyan Jiang,Jun Tan,Zhenzhi Cai,Xiaodan Lou,Jin Wang,Zhengquan Li
Dye-sensitized system holds great potential for the development of visible-light-responsive photocatalysts not only because it can enhance the light absorption and charge separation efficiency of the systems but also because it can tune the band structure of catalysts. Herein, two-dimensional (2D) Fe-MOF nanosheets (Fe-MNS) with a LUMO potential of 0.11 V ( vs. RHE) was prepared. Interestingly, it has been found that when the 2D Fe-MNS catalyst was functionalized with visible-light-responsive [Ru(bpy)] 3 2+ as a dye-sensitizer, the electrons from the [Ru(bpy)] 3 2+ can effectively inject into the 2D Fe-MNS, which resulted in a negative shift of the LUMO potential of the 2D Fe-MNS to −0.15 V ( vs. RHE). Consequently, the [Ru(bpy)] 3 2+ /Fe-MNS catalytic system exhibits a sound photocatalytic CO 2 -to-CO activity of 1120 μmol g -1 h −1 under visible-light-irradiation. The photocatalytic CO production was further ameliorated by regulating the electronic structure of the 2D Fe-MNS by doping Co ions , achieving a remarkable photocatalytic activity of 1637 μmol g -1 h −1 . This work further supports that the dye-sensitized system is an auspicious strategy worth exploring with different catalysts for the development of visible-light-responsive photocatalytic systems.
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PubMed
高影响因子
Membranes
·
2021
·Vol. 11
·期 9
·693
·
IF 4.106
Fei Guo,Bingzhang Li,Rui Ding,Dongsheng Li,Xiaobin Jiang,Gaohong He,Wu Xiao
Mixing a polymer matrix and nanofiller to prepare a mixed matrix membrane (MMM) is an effective method for enhancing gas separation performance. In this work, a unique UiO-66-decorated halloysite nanotubes composite material (UiO-66@HNT) was successfully synthesized via a solvothermal method and dispersed into the Pebax-1657 matrix to prepare MMMs for CO2/N2separation. A remarkable characteristic of this MMM was that the HNT lumen provided the highway for CO2diffusion due to the unique affinity of UiO-66 for CO2. Simultaneously, the close connection of the UiO-66 layer on the external surface of HNTs created relatively continuous pathways for gas permeation. A suite of microscopy, diffraction, and thermal techniques was used to characterize the morphology and structure of UiO-66@HNT and the membranes. As expected, the embedding UiO-66@HNT composite materials significantly improved the separation performances of the membranes. Impressively, the as-obtained membrane acquired a high CO2permeability of 119.08 Barrer and CO2/N2selectivity of 76.26. Additionally, the presence of UiO-66@HNT conferred good long-term stability and excellent interfacial compatibility on the MMMs. The results demonstrated that the composite filler with fast transport pathways designed in this study was an effective strategy to enhance gas separation performance of MMMs, verifying its application potential in the gas purification industry.Keywords:composite material;UiO-66;HNT;mixed matrix membrane;CO2/N2separation
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PubMed
高影响因子
ChemSusChem
·
2021
·Vol. 14
·期 16
·3293-3302
·
IF 8.928
Dawei Zhao,Yimin Xuan,Kai Zhang,Xianglei Liu
Graphical Photocatalytic CO 2 reduction : Benefiting from the synergistic effect of local high electron density at active sites and thermodynamic bicarbonate assistance, the hierarchical Bi@Bi 2 MoO 6 composite simultaneously shows good photocatalytic CO 2 reduction activity and high ethanol selectivity (92 %). Furthermore, bicarbonate ions play an important role in the formation of long-chain products due to the C−C coupling between derivative carbene intermediates and other carbon-containing intermediates. Photocatalytic CO 2 reduction is a sustainable and inexpensive method to solve the energy crisis and the greenhouse effect. However, the major stumbling blocks such as poor product selectivity, low yield of the multi-carbon products, and serious recombination of electron-hole pairs hinder practical application of photocatalysts. Herein, a high-performance Bi@Bi 2 MoO 6 photocatalyst, Bi nanoparticles grown on the surface of Bi 2 MoO 6 nanosheets with oxygen vacancies, was fabricated via a simple solvothermal approach. Benefiting from the abundant active sites and effective separation of photogenerated carriers of Bi 2 MoO 6 nanosheets, and the localized surface plasmon resonance effect of Bi nanoparticles, the Bi@Bi 2 MoO 6 sample exhibited great photocatalytic CO 2 reduction activity. Furthermore, adding NaHCO 3 into the system not only significantly increased the C 2 H 5 OH generation rate but also enhanced the product selectivity. In the photocatalytic measurement (0.17 mol L −1 CO 2 -saturated NaHCO 3 solution), the highest formation rates of CO, CH 3 OH, and C 2 H 5 OH were reached at 0.85, 0.59, and 17.93 μmol g −1 h −1 (≈92 % selectivity), respectively.
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高影响因子
危险品化学品经营许可证（带存储）