Chemical Science
·
2022
·Vol. 13
·期 21
·6224-6232
·
IF 9.969
Rui Xu,Hongan Tang,Yuanyuan Zhou,Fangzheng Wang,Hongrui Wang,Minhua Shao,Cunpu Li,Zidong Wei
The practical application of lithium–sulfur (Li–S) batteries is seriously hindered by severe lithium polysulfide (LiPS) shuttling and sluggish electrochemical conversions. Herein, the Co9S8/MoS2 heterojunction as a model cathode host material is employed to discuss the performance improvement strategy and elucidate the catalytic mechanism. The introduction of sulfur vacancies can harmonize the chemisorption of the heterojunction component. Also, sulfur vacancies induce the generation of radicals, which participate in a liquidus disproportionated reaction to reduce the accumulation of liquid LiPSs. To assess the conversion efficiency from liquid LiPSs to solid Li2S, a new descriptor calculated from basic cyclic voltammetry curves, nucleation transformation ratio, is proposed.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Ziwei Guo,Ge Bai,Bing Huang,Nan Cai,Pengran Guo,Liang Chen
A novel catalyst RM-BC (HP) was synthesized by hydrothermal treatment and pyrolysis (800 ℃) using red mud and coconut shells. Influence of different preparation conditions on catalyst performance was explored. SEM showed that RM-BC (HP) was porous and RM was successfully loaded on the outside surface and inside the pores of BC. XRD revealed that Fe 2 O 3 in RM was reduced to Fe 0 and Fe 3 O 4 in the pyrolysis process, in which pyrolysis temperature and addition ratio of coconut shells were critical. TGA-MS, FT-IR and XPS were also applied to character the catalyst. 100% of AO7 was removed within 30 min with conditions of 2 mM PS, 50 mg/L AO7 and 0.5 g/L RM-BC (HP) , and the Fe leaching was negligible. High removal rate was obtained in tap, river, and lake water. RM-BC (HP) /PS system also exhibited excellent degradation performance for other dyes (MB, MG and RhB) and antibiotics (TC, OTC and CTC). The mechanism studies demonstrated that PS was mainly activated by Fe 0 and Fe 2+ in RM-BC (HP) to produce different radicals, then 1 O 2 was generated by the reactions among these radicals to degrade AO7. Finally, nine intermediate products of AO7 were identified by FT-ICR-MS and a probable degradation pathway was proposed.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Jiami Ma,Zhixin Hu,Weihong Guo,Cheng Ni,Pan Li,Bosheng Chen,Songhua Chen,Jinlong Wang,Yanbing Guo
Ground−level ozone (O 3 ) pollution poses a significant threat to both ecosystem sustainability and human health. The catalytic decomposition of O 3 presents as a promising technology to address the issues of O 3 pollution. This study undertook the synthesis of various functionalized metal−organic framework (MOF) catalysts ( i.e., X-MIL-53(Fe) (X = H, NH 2 , NO 3 )) to delve into the influence of ligand functional groups on skeletal structure and catalytic efficacy, particularly focusing on unraveling the mechanism of O 3 catalytic decomposition under humid conditions. NH 2 -MIL-53(Fe) catalyst achieved complete O 3 decomposition under ambient temperature and high humidity conditions (RH=75 %), exhibiting a reaction rates (mol·m −2 ·s −1 ) 129 and 10.5 times greater than that of MIL-53(Fe) and NO 2 -MIL-53(Fe). The NH 2 group promotes electron flow within the backbone towards the hydroxyl group (OH) linked to Fe atom. In humid O 3 , H 2 O molecules augment the interaction between O 3 and NH 2 -MIL-53(Fe), and OH is converted to·O 2 − after deprotonation, promoting O 3 decomposition. Additionally, leveraging three−dimensional (3D) printing technology, a monolithic catalyst for O 3 decomposition was prepared for application. This study not only advances understanding of the mechanisms underlying O 3 decomposition but also offers practical solutions for addressing O 3 pollution at humid conditions.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
FUEL
·
2022
·
IF 8.035
Zhaoyang Qi,Huaifang Li,Jie Chen,Changshen Ye,Ting Qiu
The carboxyl functionalized ionic liquid ([mim(CH 2 ) 3 COOH]Cl) was prepared as a linker to combine phosphotungstic acid (HPW) and Zr(IV) ion. The obtained [mim(CH 2 ) 3 COO] 3 PW-Zr composite acted as a heterogeneous catalyst for removing DBT from liquid fuel with H 2 O 2 as an oxidant. As a result, [mim(CH 2 ) 3 COO] 3 PW-Zr possessed high catalytic activity in extractive and catalytic oxidative desulfurization (ECODS). Moreover, the [mim(CH 2 ) 3 COO] 3 PW-Zr was further exploited to grow on the surface of PEI/silica gel. And the fabricated large-grained Zr-PWIL@PEI/silica gel was used in the continuous ECODS process, and the removal of DBT could still reach more than 95% after running continuously for 16 h. More importantly, the synergistic catalytic mechanism between HPW and Zr(IV) in the ECODS process has been investigated in detail by experiments and DFT calculations. As a result, a plausible mechanism has been proposed and verified, which contains two parts: the Lewis acidic center activating H 2 O 2 to form superoxide ion radicals ( OOH), and the OOH oxidizing HPW to peroxotungstate (W(O 2 ) n ), which has a high oxidizability and stability. Thus, the effective combination of Zr(IV) and HPW active sites is a very effective strategy to promote desulfurization efficiency and utilization efficiency of H 2 O 2 . Besides, we also found the distance between the corresponding active sites of catalysts plays an essential role in ECODS reaction as it strongly influences the synergistic effect between different active sites.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
Progress in Natural Science-Materials International
·
2018
·Vol. 28
·期 4
·529-533
·
IF 2.572
Zhenmin Ding,Yufei Ma,Dandan Peng,Lu Zhang,Yumeng Zhao,Yuan Li,Shumin Han
In this work, LiBH 4 –20 wt% PP composite was prepared by ball-milling with as-synthesized hierarchical pyrolysis polyaniline (PP) and LiBH 4 , and the hydrogen sorption performance as well as catalytic mechanism of the composite was studied. It is found that the onset desorption temperature of the composite decreases to 75 °C, almost 235 °C lower than that of the milled LiBH 4 . Moreover, the composite could release 4.1 wt% H 2 and rehydrogenate a total of 4.4 wt% H 2 when the temperature raiseds up to 400 °C, showing an outstanding reversibility, which even 3.9 wt% H 2 can be kept after five cycles. Through scanning electron microscopy (SEM) observation and X-ray diffraction (XRD) analysis, we found that the PP surface forms some nanoholes after hydrogenation-dehydrogenation cycles, which leads to the confinement of some LiBH 4 in the PP nanoporous structure, therefore, the hydrogen sorption kinetics and reversibility are significantly enhanced. In addition, we also found the oxygenic groups of the PP can react with LiBH 4 forming LiBO 2 and Li 3 BO 3 , where the containing Li–B–O bonds loaded in the porous structure of the PP catalyze the hydrogenation reaction of LiBH 4 .
研究领域:
材料科学
·
能源化学
·
纳米材料
·
固态储氢
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL RESEARCH
·
2024
·
IF 1
Wuzhang Liu,Yu Shan,Songtao Liu,Ye Zhou,Yan Wang,Linwei Li,Shu Xu,Yu Chen,Xu Feng,Li Lin,Jinyue Luo,Fei Liu
Tachysterol is an intermediate product in the synthesis of vitamin D2 from ergosterol and vitamin D3 from 7-dehydrocholesterol under ultraviolet irradiation. Recent studies have shown that tachysterol is also a crucial intermediate in the synthesis of the natural anti-tumor product Chaxine C. Although there have been numerous studies on the synthesis of vitamin D2 and other photoisomers from ergosterol, research on the synthesis of tachysterol is relatively limited. In addition, the yield of tachysterol is not high (57.0%), and the mechanism is unclear. In this study, a method was developed for the qualitative and quantitative analysis of tachysterol. Meanwhile, an efficient synthesis process for tachysterol was reported. The qualitative and quantitative analysis of ergosterol isomers, including tachysterol, a precursor of vitamin D2, and photosterol, was conducted using high-performance liquid chromatography, and the quantitative method for tachysterol was confirmed using quantitative nuclear magnetic resonance. There were strong linear relationships between tachysterol content and the testing parameters, with the correlation coefficients of 0.9997 and 0.9971, respectively. The synthesis process of tachysterol from ergosterol through our self-designed photoreactors was optimized, and the effects of reaction temperature, reaction time, photoprotectants, reaction substrate concentration, and the power of ultraviolet lamps were investigated. The yield of the reaction was 85.7%, which is 28.7% higher than the previously reported results. The mechanism and by-products of the reaction were further studied using ultraviolet spectrophotometry and gas chromatography mass spectrometry. This study explored the potential for the large-scale preparation of tachysterol, particularly for the total synthesis of the anti-tumor natural product Chaxine C. It also offered insights into the synthesis of structural similar compounds and the analysis of photocatalytic reaction products.
研究领域:
生物化学
·
药物合成
·
光化学
✓ 已验证
DOI
高影响因子
ChemSusChem
·
2024
·Vol. 17
·期 12
·e202301681
·
IF 7.5
Jing Yi,Yuze Dai,Yuxuan Li,Yuhao Zhao,Yuanpeng Wu,Min Jiang,Guangyuan Zhou
Graphical A green and sustainable −COOH & −OH condensation solution polymerization method for FDCA-based polyesters. A green and sustainable −COOH & −OH condensation solution polymerization method was hereby reported for FDCA-based polyesters to avoid discoloration and toxic solvents. First, taking poly(ethylene 2,5-furandicarboxylate) (PEF) as the representative of FDCA-based polyester, enabling good white appearance PEF with M n =6.51×10 3 g mol −1 from FDCA and ethylene glycol in green solvent γ-valerolactone (GVL), catalyzed by 4-dimethylaminopyridine (DMAP) and N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride (EDC). Additionally, the molecular weight of PEF was rapidly improved ( M n >2.5×10 4 g mol −1 ) via remelting polycondensation within minutes, with the dispersity still kept relatively low dispersity ( Đ <1.40). Importantly, the −COOH & −OH condensation solution polymerization method was successfully applied for the synthesis of various FDCA-based polyesters, including diols with varying carbon chain lengths (3 to 11 carbons) and cycloalkyl diols, especially the applicability of this method to diols containing C=C double bonds, which was found to exhibit low heat resistance. Lastly, assisting with 13 C labeled 1,4-succinic acid and in-situ 13 C-NMR, an in-depth study of the possible catalytic mechanism was proposed, by which, EDC activated FDCA, and then DMAP catalyzed it with diol to yield macromolecular chain of polyester. Overall, the results provided a green and sustainable strategy for the synthesis of FDCA-based polyesters.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2012
·
IF 5.625
Hongying Zhao,Yujing Wang,Yanbin Wang,Tongcheng Cao,Guohua Zhao
A novel electro-Fenton (E-Fenton) system with the Fe 3 O 4 @Fe 2 O 3 /activated carbon aerogel (ACA) composite cathode was firstly constructed in this study. Its application on degrading imidacloprid exhibited highly catalytic efficiency over a wide applicable pH range from 3 to 9. The removal of imidacloprid and TOC achieved to 90% within 30 and 60 min, respectively. The nature of composite cathode was examined by BJH, XRD, SEM, TEM, XPS and FTIR techniques. ACA with high surface area of 2410 m 2 g −1 and multiplicated porosities composed of micropores and mesopores worked not only as cathode but also as Fenton catalyst support, enhancing oxidation activity. We proposed reasonable E-Fenton oxidation mechanisms with Fe 3 O 4 @Fe 2 O 3 /ACA cathode at acidic and basic conditions. At pH 3, it followed a Haber–Weiss mechanism that the dissolved iron ions and surface Fe(II) sites catalyzed the decomposition of H 2 O 2 to generate hydroxyl radicals ( OH). While at pH 9, it was expected the formation and deactivation of H 2 O 2 complex as well as the catalytic decomposition of H 2 O 2 with surface Fe(III) and Fe(II) sites to produce both superoxide anion ( O 2 − /HO 2 ) and hydroxyl radicals ( OH), involving an in situ recycling of iron oxide (FeO·Fe 2 O 3 → Fe 2 O 3 ).
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
iScience
·
2023
·
IF 5.8
Cheng Wang,Zirui Qiao,Yulan Tian,Haijun Yang,Huaqiang Cao,Anthony K. Cheetham
Imines are important intermediates for synthesizing various fine chemicals, with the disadvantage of requiring the use of expensive metal-containing catalysts. We report that the dehydrogenative cross-coupling of phenylmethanol and benzylamine (or aniline) directly forms the corresponding imine with a yield of up to 98%, and water as the sole by-product, in the presence of a stoichiometric base, using carbon nanostructures as the “green” metal-free carbon catalysts with high spin concentrations, which is synthesized by C(sp 2 )-C(sp 3 ) free radical coupling reactions. The catalytic mechanism is attributed to the unpaired electrons of carbon catalysts to reduce O 2 to O 2 ·− , which triggers the oxidative coupling reaction to form imines, whereas the holes in the carbon catalysts receive electrons from the amine to restore the spin states. This is supported by density functional theory calculations. This work will open up an avenue for synthesizing carbon catalysts and offer great potential for industrial applications.
研究领域:
化学
·
材料科学
·
催化反应
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Zeyu Liu,Yao Liu,Lin He,Qiang Xue,Jianwei Zhao,Shengyan Pu
Accurate and rapid detection of trace Cr(VI) in water is essential for environmental pollution control and human health protection. In this study, we developed a novel electrochemical sensor co-modified with polyaniline-functionalized Fe 3 O 4 nanoparticles and a Ce-based metal–organic framework (Ce-MOF). The unique interface morphology and outstanding electrocatalytic properties of the modified electrode enabled ultra-sensitive detection of Cr(VI), with excellent linearity in the range of 1 to 1000 μg/L and a limit of detection (LOD) of 0.05 μg/L. Combined with DFT and XPS analysis, the catalytic mechanism of the Ce and Fe bimetals for Cr(VI) detection was deeply investigated. The Cr d-orbitals are hybridized with Fe d-orbitals and O p-orbitals around −5.0 eV, indicating strong electronic coupling between Cr atoms and Fe/O atoms is achieved based on the optimized model structure (Fe 3 O 4 /Ce-MOF/Cr). Additionally, Ce facilitated the valence cycling of Fe, promoting Fe 2+ generation and enhancing electron donation, which in turn improved the reduction of Cr(VI). Significantly, we firstly integrated this composite with laser-induced graphene technology to create flexible integrated electrodes that meet practical requirements, breaking through the previous limitations of poor portability and expanding application scenarios. This study provides new insights for accurate, efficient, and portable on-site detection of Cr(VI) in water environments.
研究领域:
环境科学
·
材料科学
·
分析化学
✓ 已验证
DOI
高影响因子
Methods in Enzymology
·
2024
·
IF 1.682
Xingming Pan,Liao-Bin Dong
Magnesium ions (Mg 2+ ) are crucial in class II terpene cyclases that utilize substrates with diphosphate groups. Interestingly, these enzymes catalyze reactions without cleaving the diphosphate group, instead initiating the reaction through protonation . In our recent research, we discovered a novel class II sesquiterpene cyclase in Streptomyces showdoensis . Notably, we determined its crystal structure and identified Mg 2+ within its active site. This finding has shed light on the previously elusive question of Mg 2+ binding in class II terpene cyclases. In this chapter, we outline our methods for discovering this novel enzyme , including steps for its purification , crystallization , and kinetic analysis.
研究领域:
生物化学
·
结构生物学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Qinxue Yang,Xiaofang Yang,Ying Yan,Chuang Sun,Hanjun Wu,Jie He,Dongsheng Wang
In this work, ferromanganese oxides (FMOs) synthesized with different Fe and Mn ratio using sol–gel method showed good activity in the activation of peroxymonosulfate (PMS) for tetracycline degradation. The structure and surface characterizations of the FMOs were measured using XRD, BET and XPS. The variation of the catalytic performance of FMOs in the degradation of TC was investigated with varied initial conditions. The FMO-46 structured as FeMnO 3 with cubic structure could activate PMS efficiently due to the large surface area and surface Mn(III) sites. While the high catalytic activity of FMO-73 was attributed to the high percentage content of surface Fe(II) and Mn(II). The more vicinities of Fe and Mn exist on the surface of FMOs result in a better catalytic activity towards PMS and degradation of TC. The catalytic mechanism was elucidated by detecting the reactive oxidation species generated using ESR measurement and radical scavengers. It was found that Mn-oxides with Fe-regulated-surface active sites were expected to enhance the catalytic activity in the generation of SO 4 − . The experimental results demonstrated that SO 4 − had a higher contribution to degrade tetracycline in PMS/FMO system than OH. This study proves that surface regulated FMOs can efficiently activate PMS to degrade refractory organic pollutants as an environmentally friendly catalyst.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）