FUEL
·
2023
·
IF 7.4
Qihuang Huo,Yahui Wang,Huijun Chen,Yu Feng,Lina Han,Weiren Bao,Liping Chang,Jiancheng Wang,Kechang Xie
It is a win–win strategy to prepare mercury sorbents from low-cost high-sulfur raw materials. In part 1, mercury sorbents with excellent performance were prepared from high inorganic sulfur coal through KOH activation. However, this method does not work for high organic sulfur coal. In this work, a two-step preparation method is developed to prepare mercury sorbents from high organic sulfur coal. The first step is the co-pyrolysis/carbonization of Fe 2 O 3 and coal, during which organic sulfur in coal is converted into FeS x . XPS shows that the percentage of S x 2– /S on the surface of the carbonized samples gradually increases from 5.4% to 22.2% with the m(Fe):m(S o ) ratio from 0:4 to 5:4. The second step is KOH activation, and it converts FeS x into various S species, including C-S, S 0 , S 2 2− and S 2− . Among the prepared mercury sorbents, LF+3Fe/4S-A (m(Fe):m(S o ) = 3:4) shows the best mercury removal performance, and its mercury removal efficiency remains above 84% for 120 min under N 2 +O 2 at 120 °C. The Hg-TPDD and XPS results indicate that S*, including C-S, S 0 and S 2 2− , are the major active sites for mercury removal rather than Fe element, and HgS is the main existing form of mercury on the used sorbents. Besides LF coal, this two-step process is also applicable to other high organic sulfur coals (such as LL coal, WJZ coal, and SY coal) and high-sulfur petroleum coke.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2023
·
IF 4.2
Danxia Lin,Shi Tu,Liang Yu,Yinuo Yuan,Ying Wu,Xin Zhou,Zhong Li,Qibin Xia
The separation of light hydrocarbons like methane, ethane, and propane is an important section of the chemical industry. Herein, we reported a novel porous metal–organic framework (MOF) Cu-IPA and investigated its CH4/C2H6/C3H8 separation performance, particularly for efficient capture of C2H6 and C3H8 at low concentrations. Cu-IPA featured 1D hexagonal channels and triangular channels decorated with extensive oxygen atoms. It showed high C2H6 and C3H8 capacities in the low-pressure region, where C3H8 uptake at 5 kPa was 1.62 mmol/g and C2H6 uptake reached 1.33 mmol/g at 10 kPa, suggesting the strong adsorption affinities toward C2H6 and C3H8. For an equimolar C2H6/CH4 mixture, Cu-IPA exhibited a considerable IAST selectivity of 40, exceeding most reported MOF adsorbents. Excellent CH4/C2H6/C3H8 separation performance for Cu-IPA can be attributed to its appropriate pore size and abundant accessible oxygens atoms in the triangular channel. The molecular simulation revealed that Cu-IPA tended to form stronger C–H···O interactions with C2H6 and C3H8 due to the higher polarizabilities, resulting in larger interaction differences between C2H6/CH4 and C3H8/CH4. Breakthrough tests also supported the excellent dynamic separation performance and recyclability of Cu-IPA.
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高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Guofu Ren,Zhiguo Qu,Xueliang Wang,Guobin Zhang
The gas diffusion layer (GDL) plays a vital role in water management of proton exchange membrane fuel cells. In this study, GDLs with nanoscale gradient pore sizes (nano-GDLs) are fabricated using electrospinning to explore the influence of the gradient layer number and degree of the pore size gradient on the water transport performance. The breakthrough pressure and water saturation tests indicate that nano-GDLs with uniform and gradient structures have higher breakthrough pressures and lower water saturation compared with those of the commercial Toray GDL, which facilitates back diffusion of water through the membrane and water discharge in the GDL. Specifically, among the nano-GDLs with a gradient structure, the three-layer medium-gradient nano-GDL sample (3-MG) possesses the maximum breakthrough pressure and minimum water saturation ratio. The fuel cell test determined that the maximum power density of the 3-MG nano-GDL sample is 14% higher than that with commercial Toray GDL without cathode humidification .
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TALANTA
·
2023
·
IF 6.1
Shutong Yang,Yanqiu Chu,Liancheng Gu,Chuan-Fan Ding,Fengyan Wang
Noncovalent ternary complexes between cyclodextrins (CDs), small molecules and alkali earth cations drew growing attention due to their potential application in many chemical and pharmaceutical fields. To date, the main factors affect the formation mechanism of noncovalent ternary complexes in gas phase have not been fully investigated. In this study, ternary complexes of CDs, divalent metal cations and amino acids (AAs) were investigated by electrospray ionization mass spectrometry (ESI-MS), demonstrating the formation of 1:1:1 stoichiometric noncovalent ternary complex of [CD + cation(II)+AA] 2+ in gas phase. The results revealed that only +2 valence cations can form stable ternary complexes in ESI-MS. The ratio of peak intensities for [β-CD + Mg(II)+AA] 2+ to those for [β-CD + Mg(II)] 2+ hydrophobicity of AAs was also determined to discuss the effect of hydrophobicity of AAs. Exceptions exist for Pro, Gly, and Val indicated that other factors such as side-chain structure and rigidity of AAs can also influence the binding strength for ternary complexes. Collision induced dissociations (CID) were performed to further confirm the formation of the β-CD ternary complexes, revealing the binding strength of [CD + Mg(II)+Phe] 2+ decreased in the order of γ-CD, β-CD, and α-CD. Although Leu and Ile are isomers, the ESI-MS demonstrated the peak intensity for ternary complexe of [β-CD + Mg(II)+Ile] 2+ exhibited stronger than that of [β-CD + Mg(II)+Leu] 2+ , DFT theoretical calculations were conducted to explain the phenomenon. The calculation indicated when Mg 2+ existing, the conformations of the two ternary complexes could be affected due to the electrostatic force . In the complexes, the Leu and Ile turn a way round, inserting to the cavity with their carboxylic acid side into the large rim side of β-CD and interacting with Mg 2+ . This work not only clearly explained the factors influencing the formation of [CD + cation(II)+AA] 2+ in gas phase, but it also provides an insight in designing ternary complexes for areas such as drug design and chiral discrimination.
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PubMed
高影响因子
CHINESE JOURNAL OF STRUCTURAL CHEMISTRY
·
2023
·
IF 2.2
Qian Liu,Yingyi Wen,Jian-Ze Xiao,Shao-Zhen Luo,Guan-E Wang,Peng-Yi Tang,Xiao-Liang Ye,Gang Xu
The poor sensitivity of metal-oxide (MO) sensing material at room temperature can be enhanced by the modification of noble metal catalysts . However, the large size and uncontrollable morphology of metal nanoparticles (NPs) compromise the catalytic activity and selectivity. Downsizing metal NPs to the atomic level is a promising solution because it offers high activity and selectivity. Nevertheless, a facile and universal approach for stable loading atomic-level metal on MO-based sensing materials is still challenging. Herein, we present a strategy to construct synergetic coordination interface for uniform loading of atomic-level metal catalysts on MO-based gas-sensing materials using a difunctional mediator layer. In this work, atomically dispersed Pt catalysts are coordinately anchored on ZnO nanorods (NRs) using polydopamine (PDA) as a mediator. As a result, compared with pristine ZnO NRs, a six-fold enhanced response of 18,489% is achieved toward 100 ppm NO 2 on 0.20 wt%Pt–ZnO@PDA-1.5 nm, and the selectivity is also promoted. Such sensitivity is higher than that of most reported noble metal-modified MO NO 2 -sensing materials. This work provides a simple and general strategy for building highly sensitive and selective gas-sensing materials using atomic-level noble metal catalyst.
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MOLECULES
·
2023
·Vol. 28
·期 5
·2028
·
IF 4.6
Chaohua Song,Longfei Peng,Yinhui Li,Yawei Du,Zan Chen,Weixin Li,Cuijia Duan,Biao Yuan,Shuo Yan,Sibudjing Kawi
Novel polymers applied in economic membrane technologies are a perennial hot topic in the fields of natural gas purification and O2enrichment. Herein, novel hypercrosslinked polymers (HCPs) incorporating 6FDA-based polyimide (PI) MMMs were prepared via a casting method for enhancing transport of different gases (CO2, CH4, O2, and N2). Intact HCPs/PI MMMs could be obtained due to good compatibility between the HCPs and PI. Pure gas permeation experiments showed that compared with pure PI film, the addition of HCPs effectively promotes gas transport, increases gas permeability, and maintains ideal selectivity. The permeabilities of HCPs/PI MMMs toward CO2and O2were as high as 105.85 Barrer and 24.03 Barrer, respectively, and the ideal selectivities of CO2/CH4and O2/N2were 15.67 and 3.00, respectively. Molecular simulations further verified that adding HCPs was beneficial to gas transport. Thus, HCPs have potential utility in fabrication of MMMs for facilitating gas transport in the fields of natural gas purification and O2enrichment.Keywords:6FDA-based polyimide;hypercrosslinking polymers;gas transport;molecular simulations
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PubMed
高影响因子
ANALYTICA CHIMICA ACTA
·
2023
·
IF 6.2
Tao Sun,Ruonan Chen,Qiuchen Huang,Mengyi Ba,Zhiqiang Cai,Haipeng Chen,Yueheng Qi,Hong Chen,Xianming Liu,Donatella Nardiello,Maurizio Quinto
The separation of aromatic isomers, in particular xylene isomers, represents a big issue in chemical and petroleum industries , owing to their similar molecular sizes and boiling points. In this work, the investigation ofpillar[6]arene derivative modified by long alkyl chains (P6A-C10) as a stationary phase for high-resolution gas chromatographic (GC) separations of xylene isomers is presented. Pillar[n]arenes are a new class of macrocyclic hosts that can accommodate specific guests due to their highly symmetrical and rigid pillar architectures with π -electron rich cavities. The P6A-C10 column showed high-resolution performance towards xylene isomers, with peculiar advantages if compared with the commercial HP-5, HP-35, DB-17, and PEG-20Mcolumns.A quantum chemistry calculation has been performed, showing a difference in non-covalent interactions with the P6A-C10 pillar framework, which leads to specific selectivity for xylene isomers.Furthermore, the P6A-C10 column exhibited good repeatability.
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PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2023
·
IF 4.8
Yanshuxian Liu,Yilei Fan,Yin Zheng,Zhongping Huang,Huijun Liu,Zhenlu Shen,Yu Xu,Danxia Yu,Xuedong Xiao
A sensitive and novel method for the determination of methamphetamine (MAMP), 3,4-methylenedioxymethamphetamine (MDMA) and their metabolites amphetamine (AMP), 3,4-methylenedioxyamphetamine (MDA) in human hair was established by the employment of flash evaporation-gas chromatography/mass spectrometry (FE-GC/MS) combined with micro-reaction device. 0.30 mg human hair after cutting was put into a sealed glass capillary and heated at 270 °C in a pyrolyzer for 0.5 min. MAMP, AMP, MDMA and MDA evaporated from the hair were converted into their corresponding trifluoroacetylation product in a 60 °C water bath for 30 min with the acetylation by 2 μL trifluoroacetic anhydride (TFAH). Thus, amphetamines (AMPs) in human hair were separated and detected by GC/MS in SIM mode. The obtained calibration curves showed good linearity with the concentrations of MAMP, MDMA and MDA at 1–100 ng/mg, and AMP at 2–100 ng/mg. The linear correlation coefficients (r) were all larger than 0.996. Limits of detection for MAMP, AMP, MDMA and MDA were 0.67, 0.07, 0.17 and 0.07 ng/mg respectively. Limits of quantification for MAMP, AMP, MDMA and MDA were 2.00, 0.20, 0.50 and 0.20 ng/mg respectively. The precision over a range of 0.63–9.98 % were obtained with the recoveries of 92.7–115.2 % for AMPs. Five positive hair samples, three suspicious hair samples and two negative hair samples were successfully analyzed. The results of FE-GC/MS with micro-reaction device were comparable with those found by the referenced method. It was demonstrated that the developed method had potential applications for the analysis of AMPs in hair.
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Inorganic Chemistry Frontiers
·
2019
·Vol. 6
·期 8
·2043-2049
·
IF 5.934
Di Liu,Guangsheng Pang,Zhiyong Tang,Shouhua Feng
Interfacial engineering has demonstrated a significant effect on fabricating highly efficient membranes for gas separation. Herein, we introduced a new way to prepare a soft MOF membrane with a modified interface using polyelectrolyte branched polyethyleneimine (PEI) as the joint material. Assembled with layered graphene oxide (GO) and zeolitic imidazolate framework-8 (ZIF-8) nanocrystals, branched PEI not only functions as a soft coat onto the ZIF-8 surface to overcome the rigid nature but also well connects with GO nanosheets via electrostatic attraction, thus preventing the fracture of the membrane. When employed as the gas separation membrane for H2/CH4, the long gas diffusion pathway determined by layered GO and the accurate sieving effect endowed by ZIF-8 enable the remarkable permeance and selectivity. Furthermore, by simply altering the content of GO nanosheets and ZIF-8 nanocrystals in the composite membrane, one can easily adjust the permeance and selectivity toward the separation of H2/CH4 gas mixture.
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高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Wenmin Zhang,Cheng Peng,Defang Liu,Yangfang Cheng,Jianqing Wu
In order to improve the gas permeability and thermal shock resistance of the ceramic membranes applied in high temperature gas-solid separation techniques, fused silica and graphite particles were used as the primary raw material and pore-former agent, and the spray coating based-on PVA sealing was applied to prepare the separation membrane. These approaches remarkably decreases filtration resistance by increasing support permeability and reducing the intrusion of ceramic membrane forming particles into the support as well as the thickness of the membrane. The fabricated membrane had an average pore diameter of 9.85 μm and a gas permeability value of 8.2 × 10 4 m 3 /(m 2 h bar), its dust removal efficiency reached 98.6%.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2019
·
IF 5.107
Zimu Xu,Xiaojuan Xue,Shuheng Hu,Yunxia Li,Jie Shen,Yan Lan,Rongxing Zhou,Fan Yang,Cheng Cheng
Norfloxacin (NOR) is a typical kind of Fluoroquinolone antibiotics which is extensively used around the world. Residues of NOR have been found continuously increasing in the water systems thus posing detrimental effects to the aquatic ecosystem and human health. In this study, the degradation effect and mechanism on NOR in aqueous solution are investigated by gas-liquid phase dielectric barrier discharge (DBD) plasma combined with different catalysts (H 2 O 2 or Fe 2+ ). The concentrations of three representative plasma-generated long-lived reactive species (H 2 O 2 , O 3 and N O 3 - ) were measured in dH 2 O and found enhancing with the lengthening discharge period. Variations on the treatment parameters were carried out in discharge power, initial solution pH and the concentration of catalysts. A discharge power at 60 W provided optimal balance on the degradation effect and energy efficiency would be beneficial, while there is not much impact from the initial solution pH on NOR degradation. Both H 2 O 2 and Fe 2+ at low concentration (0.5–10 mg/L of Fe 2+ , 0.1–1.0 mmol/L of H 2 O 2 ) were observed contributing to the improvement on the NOR degradation rate, while inhibition would occur at high concentration (10–20 mg/L of Fe 2+ , 1.0–2.0 mmol/L of H 2 O 2 ). The DBD/H 2 O 2 (0.5 mmol/L)/Fe 2+ (10 mg/L) system was found the optimal condition to achieve a high NOR degradation rate of more than 98% after plasma treatment for only 0.5 min at discharge power of 60 W. Moreover, 72.3 ± 1.7% of the total organic carbon (TOC) in NOR solution have been removed in the DBD/Fe 2+ (10 mg/L) system at 15 min which signifies a high mineralization efficiency. The cleavage of piperazine ring and quinolone ring, defluorination and hydroxylation are considered the major pathways for NOR degradation. The biological toxicity of the plasma/Fe 2+ -induced degradation intermediates has been detected and it fluctuated with the treatment time and finally declined. Therefore, the DBD/catalyst system could be an effective and promising method on pharmaceutical wastewater treatment in the future.
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高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Xiu-Xiu Fang,Wen-Min Liao,Jian-Dong Song,Wen-Zhi Jia,Yun Wang,Ji-Qing Lu,Meng-Fei Luo
A series of 3V-xFe/MgF 2 catalysts with different V/Fe molar ratios were prepared by a sol-gel method, and the effect of Fe promotion on the catalytic performance of gas-phase dehydrofluorination of 1,1,1,3,3-pentafluoropropane (HFC-245fa) was investigated. It was found that proper V/Fe ratio was helpful to improve the activity. The 3V-0.5Fe/MgF 2 catalyst (with a V/Fe ratio of 6/1) gave a HFC-245fa conversion of 76.6% at 320 °C, which was 13.4% higher than that on the 3V/MgF 2 (63.2%). The synergy between V and Fe species resulted in enhanced surface acidity which accounts for the enhanced activity. The VO x and FeO x species in the fresh catalyst could be transformed to VOF x and FeF 3 species during the reaction, which were regarded as the active sites. However, higher content of Fe in the catalyst resulted in the partial coverage of V species, which led to decline of surface acidity and thus the suppressed activity. Also, surface carbon deposition was responsible for the slight catalyst deactivation .
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