ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Jinsong Shi,Nanfu Yan,Hongmin Cui,Jianguo Xu,Yuewei Liu,Shaowei Zhang
Because of their high stability, low cost, and tunable porosity, porous carbons are of great interest as CO2 adsorbents. The influences of porosity and heteroatom doping on CO2 adsorption depend on the specific adsorption conditions. In the current work, nitrogen and sulfur co-doped carbons were prepared with the assistance of an NaCl template, and the effects of different physicochemical parameters on CO2 adsorption at 20 bar were investigated. The co-doped carbons were synthesized with sodium lignosulfonate as the starting material and urea as the nitrogen source. The material showed a high specific surface area and pore volume of 973 m2/g and 0.50 cm3/g, respectively. Sulfur-doped carbons were also prepared without the addition of urea. Sulfur doping demonstrated positive effects on CO2 adsorption at a low pressure. The sulfur-doped carbons showed adsorption properties similar to those of the co-doped carbons. The CO2 uptake at 298 K and 20 bar was in the range of 4.3–7.5 mmol/g. The experiment results also revealed that the uptake at 20 bar correlated to the specific surface area of the carbon, while the doped heteroatoms only had secondary influences.
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2019
·
IF 4.182
Yinpeng Wang,Junqi Nie,Cuifen Lu,Feiyi Wang,Chao Ma,Zuxing Chen,Guichun Yang
Polyimidazolium salts are a class of important catalysts for CO 2 cycloaddition with epoxides. However, initiator like azoisobutyronitrile or metal catalyst is often required to promote their synthetic process. Therefore, developing a clean route to synthesize polyimidazolium salts is still highly desirable. In this study, three crosslinked polymers PIM1, PIM2 and PIM3 containing imidazolium unit were constructed via nucleophilic substitution reaction of 1,3,5,7-tetrakis (4-(imidazole-1-yl)phenyl)adamantane and benzyl bromides. The structure and composition of the polymers were characterized by CP/MAS 13 C NMR, FT-IR and XPS. Different porosities were observed for PIMs, and PIM2 has a larger BET surface are than that of PIM1 and PIM3. Accordingly, the polymeric imidazolium salt PIM2 shows superior activity for catalyzing cyclic addition of CO 2 with a variety of epoxides without any solvent or cocatalyst, giving the cyclic carbonates in excellent yields. In addition, PIM2 shows high stability and easy recyclability.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Bin Han,Jianing Song,Shujie Liang,Weiyi Chen,Hong Deng,Xinwen Ou,Yi-Jun Xu,Zhang Lin
CO 2 adsorption is a critical step for CO 2 photoreduction, especially in diluted CO 2 , whereas an in-depth understanding of CO 2 adsorption effects is still lacking. Herein, isostructural NiCo 2 O 4 and MgCo 2 O 4 hierarchical hollow nanocages (NiCo 2 O 4 HCs and MgCo 2 O 4 HCs) have been ingeniously constructed for diluted CO 2 photoreduction. NiCo 2 O 4 HCs exerts an apparent quantum yield of 1.56% with CO selectivity of 89%, exceeding most previous inorganic catalysts in pure CO 2 . Nevertheless, MgCo 2 O 4 HCs is almost inert, even though it shows higher CO 2 uptake ability. DFT calculations results indicate that CO 2 molecule adsorbed on Ni sites can be readily reduced to CO, while the CO 2 on Mg sites cannot participate in this reaction. Therefore, only adsorbed CO 2 which can participate in reduction reactions, named active adsorption , can accelerate the whole reactions. This work unearths atomic-level insights into the relation between CO 2 adsorption and reduction, providing fundamental guidance to improve photocatalytic performance.
✓ 已验证
产品关联
DOI
高影响因子
POLYMER TESTING
·
2019
·
IF 2.943
Yingying Zhou,Mingfeng Chang,Xiyu Zang,Lan Zheng,Yuqi Wang,Le Wu,Xiaolong Han,Yuqing Chen,Yunsong Yu,Zaoxiao Zhang
The CO 2 capture materials and technology have received much attention in recent years due to the environmental deterioration caused by the greenhouse gas emissions . Several imidazolium polymeric ionic liquids (PILs) were synthesized and immobilized on mesoporous γ-Al 2 O 3 (MA) using ultrasonic immersion method. The prepared adsorbents were characterized by FT-IR, 1 H NMR, EA , TGA , SEM, XRD , BET and TEM, indicating the successful synthesis of the desired PILs/MA. The CO 2 adsorption capacity was investigated under different loading ratios, temperatures, pressures and CO 2 flow rates , whose optimal adsorption conditions were 1/1, 313 K, 5 bar and 10 mL/min, respectively. Moreover, the adsorption curves for P[VCIm]Cl/MA were coincident with pseudo-second order model, and the CO 2 adsorption kinetics model was calculated and obtained. Compared with P[VRIm]Cl and P[VEIm]Cl, P[VCIm]Cl/MA demonstrated an outstanding adsorption amount of 0.562 mmol/g under the suitable conditions, and its regeneration efficiency could achieve 94.8% after 5 times cycle.
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2019
·
IF 3.683
Zidong Zhang,Yuming Tu,Hui Yu,Weidong Liu,Zhiyong Zhou,Zhongqi Ren
Extraction is a common approach to separating aromatics and alkanes, but solvent recovery remains an issue. The polarity, hydrophobic/hydrophilic balance, and other properties of switchable solvents can be reversibly changed in the presence of various triggers, and taking advantage of this property can greatly simplify the process of solvent recovery. In this work, quaternation and anion exchange were used to prepare several switchable solvents by introducing OH– ions to derivatives of the amidine compound 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). The resulting compounds exhibited reversible switching in response to exposure to CO2. Using toluene/n-heptane as a model hydrocarbon mixture, a reversible phase change extraction process was established. Among the four switchable solvents prepared, [C2DBU]OH showed the highest selectivity value and so was used to investigate the effect of various parameters on hydrocarbon separation. The extraction process was found to rapidly reach equilibrium when a two-phase system was generated by bubbling CO2 through the extraction mixture. Increasing the proportion of the solvent increased the selectivity for toluene, while a 1:1 ratio between the solvent and the toluene/n-heptane mixture enhanced the extraction. Increasing the initial toluene concentration reduced the selectivity for toluene, with a value of 5.97 at a toluene concentration of 20%. The switchable solvent recovered its initial state when heated at 60 °C for 1 h. Upon being reused after removal of CO2, the solvent exhibited poor separation characteristics, although the selectivity coefficient remained constant at approximately 3.1 during 10 regenerations. Finally, the mechanism of the switchable solvent effect and modeling of experimental data were investigated.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2019
·
IF 5.107
Meidi Wang,Kaidong Quan,Xiaohong Zheng,Yu Cao,Xiangyu Cui,Ming Xue,Fusheng Pan
Two-dimensional (2D) covalent organic nanosheets (CONs) present versatile 2D materials, which hold great promise in mixed matrix membranes. The facile synthesis of CONs for the fabrication of mixed matrix membranes represents the development trend. Herein, mixed matrix membranes with facilitated transport ability were prepared based on self-exfoliated covalent organic nanosheets (CONs) and poly(ether-block-amide) (Pebax® MH 1657) matrix. The self-exfoliated TpDT CONs were facilely synthesized via Schiff base condensation reaction between 1,3,5-Triformylphloroglucinol (Tp) and 3, 5-diamino-1,2,4-triazole (DT). Abundant amine groups on TpDT CONs skeleton served as facilitated transport carriers to promote the transport of CO 2 by reversible nucleophilic addition reactions. And the highly ordered channels of TpDT CONs allowed the rapid transportation of CO 2 molecules to reach the facilitated transport carriers. Moreover, the incorporated TpDT CONs disturbed the packing of the Pebax chains by the intervention effects and increased the chain mobility. The facilitated transport carriers from TpDT CONs and the optimized structure endowed the as-prepared membranes with elevated permeance and selectivity. Specially, the Pebax-TpDT/PVDF membranes with 1 wt% TpDT CONs achieved an optimum CO 2 /CH 4 separation performance with a separation factor of 36.0 and a CO 2 permeance of 142.3 GPU, which were increased by 68% and 131%, respectively, compared with the pristine Pebax membrane.
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION SCIENCE AND TECHNOLOGY
·
2019
·
IF 1.354
Airong Li,Dan Luo,Lele Jiang,Jie Wang,Yi Zhou
A series of experiments on CO2 hydrate formation were carried out in the presence of titanium dioxide (TiO2), silicon dioxide (SiO2), multi-walled carbon nanotubes (MWNTs) nanoparticles. The effects of these nanoparticles on induction time, final gas consumption, and gas storage capacity have been investigated at the temperature of 274.15 K and the initial pressure of 5.0 MPa.g. The induction time of CO2 hydrate formation was remarkably shortened to 12.5 min in the presence of 0.005 wt% MWNTs nanoparticles. The high thermal conductivity and heat capacity of MWNTs nanoparticles presented better heat transfer, and large surface area provided more suitable sites for heterogeneous nucleation of CO2 hydrate.
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2019
·
IF 5.383
Fajun Li
Metals have proved to be cracking catalysts for electrochemical reduction of CO 2 to formate (ERCO 2 F), but they suffer from a high overpotential caused by weak adsorption of CO 2 . As far as we know, N-containing polymers, with N atoms lowering the activation energy through efficient trapping of CO 2 , can make contributes to ERCO 2 F. Here, a composite electrode of metal and N-containing conjugated polymer at the interface was used for CO 2 reduction. It exhibited superior Faradaic efficiency (94% ± 1%) and space time yield (306 ± 14 μmol h −1 cm −2 ) at the electrolytic potential of −1.70 V for electrochemical reduction of CO 2 to formate. Polyaniline film was obtained by potentiostatic reduction of pre-completed polyaniline nanowires from polymerizing aniline on Ni foam. Then the spontaneous oxidation of base polyaniline was used to promote the reduction of tin deposition on its surface.
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2019
·Vol. 43
·期 44
·17267-17274
·
IF 3.069
Pengcheng Su,Xu Zhang,Zehai Xu,Guoliang Zhang,Chong Shen,Qin Meng
Recently, great improvements have been achieved in the fabrication of adsorbents. However, designing adsorbents with high adsorption capacity and superior selectivity still remains a big challenge. In the present study, a novel cost effective NH2-HCP adsorbent for toxic dyes and CO2/N2 separation was facilely synthesized through the one-step Friedel–Crafts alkylation reaction of m-phenylenediamine (MPD). The adsorption process under different adsorption parameters, namely, contact time and initial dye concentration were investigated in detail to explore the adsorption characteristics of the NH2-HCPs. Moreover, the experimental results demonstrated that the equilibrium adsorption isotherm and adsorption kinetics for anionic dye adsorption onto the NH2-HCPs fitted well with the Langmuir model and pseudo-second-order model, respectively. With a mesoporous structure and a high density of active amino groups, the amino-functionalized hypercrosslinked polymers (NH2-HCPs) not only showed an unprecedented adsorption capacity of 3290 mg g−1 for the anionic dye X-3B and almost no adsorption toward the cationic dye, but also possessed an excellent CO2/N2 selectivity of 122.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Hongyu Cen,Jiaojiao Cao,Zhenyu Chen,Xingpeng Guo
The corrosion inhibition performance of 2-mercaptobenzothiazole (MBTH) for carbon steel in a CO 2 -H 2 O system was investigated by weight loss, surface analysis, electrochemical measurements, and quantum chemical calculations. Results showed that MBTH could effectively protect carbon steel from CO 2 corrosion and inhibition efficiency of MBTH in supercritical CO 2 was higher than that in non-supercritical CO 2 situation. The differential capacitance curves revealed that excess positive charges would be on the surface of carbon steel in the supercritical-CO 2 system while negative charges accumulated on carbon steel surface in non-supercritical CO 2 condition. The adsorption model was proposed to explain the inhibition mechanism of MBTH.
✓ 已验证
产品关联
DOI
高影响因子
Greenhouse Gases-Science and Technology
·
2019
·Vol. 9
·期 2
·349-359
·
IF 1.693
Ji Liu,Xiaoshan Li,Zewu Zhang,Liwei Li,Yajun Bi,Liqi Zhang
The carbon dioxide post-combustion capture process using amine solutions is considered the most appropriate method for CO 2 capture from flue gas in power plants. This paper focuses on the CO 2 capture performance of six common organic amines. Two amines, piperazine (PZ) and diethylenetriamine (DETA), which showed better performance, were then filtered out to form amine blends to improve performance further. The absorption heat from the CO 2 absorbing process was measured directly using an advanced C80 micro calorimeter for more accurate calculation of regenerative energy consumption. Experimental results confirmed the optimal amine blend to be 10% PZ plus 20% DETA, with a 42% increase in absorption capacity and a 9% increase in initial absorption rate compared to traditional 30% monoethanolamine (MEA). The regeneration energy consumption of this chosen PZ-DETA blend was calculated to be 3.979 GJ/ton CO 2 , a decrease of 9% compared with MEA. Moreover, it led to an improvement of about 55% in stable cyclic absorption capacity in comparison with 30% MEA. It was confirmed that this PZ-DETA blend can bring practical economic benefits to industrial applications when replacing the current 30% MEA solution. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2019
·Vol. 10
·期 1
·1-8
·
IF 11.878
Chen Shichuan,Wang Hui,Kang Zhixiong,Jin Sen,Zhang Xiaodong,Zheng Xusheng,Qi Zeming,Zhu Junfa,Pan Bicai,Xie Yi
The photofixation and utilization of CO 2 via single-electron mechanism is considered to be a clean and green way to produce high-value-added commodity chemicals with long carbon chains. However, this topic has not been fully explored for the highly negative reduction potential in the formation of reactive carbonate radical. Herein, by taking Bi 2 O 3 nanosheets as a model system, we illustrate that oxygen vacancies confined in atomic layers can lower the adsorption energy of CO 2 on the reactive sites, and thus activate CO 2 by single-electron transfer in mild conditions. As demonstrated, Bi 2 O 3 nanosheets with rich oxygen vacancies show enhanced generation of •CO 2 – species during the reaction process and achieve a high conversion yield of dimethyl carbonate (DMC) with nearly 100% selectivity in the presence of methanol. This study establishes a practical way for the photofixation of CO 2 to long-chain chemicals via defect engineering.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）