COMBUSTION AND FLAME
·
2020
·
IF 4.57
Zhi-Hao Jin,Jin-Tao Chen,Shu-Bao Song,Dong-Xu Tian,Jiu-Zhong Yang,Zhen-Yu Tian
The pyrolysis of three-component surrogate fuel for jet fuel has been studied experimentally in flow reactor using synchrotron photoionization and molecular beam mass spectrometry techniques with temperature range of 850–1150 K. Alkenes are the most abundant products in the decomposition process . Other important intermediates such as alkanes, alkynes, polycyclic aromatic hydrocarbons were also identified and quantified. Detailed kinetic reaction model involving 462 species and 3170 reactions have been developed by validating against the measured results as well as oxidation data reported previously with reasonable predictions. Detailed rate of production and sensitivity analysis indicated T135MCH mainly decay through demethylation and H-abstraction reactions. Moreover, n-propylbenzene consumption is more sensitive to CH 3 than H, while n-dodecane and T135MCH prefer H radical. The reactions between fuel and fuel-derived radicals show limited effect on surrogate fuel consumption. Reactivity changes of NPB and NC 12 H 26 were investigated through the comparison of fuel conversion ratio. The coupling effect was displayed via the common and important sensitive reactions which are related to the H and CH 3 radicals. Present experimental data and reaction model will contribute to a better understanding of combustion behavior of 3C surrogate fuel. Thus, the results of present work could contribute to comprehensive investigation of jet fuel combustion properties .
研究领域:
化学工程
·
燃烧科学
·
能源研究
✓ 已验证
DOI
高影响因子
ENERGY & FUELS
·
2024
·
IF 5.2
Wenbo Jia,Yueyuan Wang,Shaohua Ling,Liren He,Binghe Chen,Songtao Liu,Chuanmin Chen,Yue Cao
Fast selective catalytic reduction (SCR) atmosphere can significantly improve the NOx removal activity of VWTi catalysts, while the catalytic performance and reaction pathway of Hg0 oxidation in a fast SCR atmosphere are still unclear. In this paper, the catalytic activity of simultaneous NOx removal and Hg0 oxidation over VWTi catalysts in a simulated fast SCR atmosphere was investigated for the first time. The results showed that VWTi catalysts possessed a wide NOx removal active temperature window and a high Hg0 oxidation activity in a fast SCR atmosphere. The X-ray photoelectron spectroscopy (XPS) and Hg temperature-programmed desorption (Hg-TPD) methods were used to investigate the Hg0 oxidation process over VWTi catalysts in a fast SCR atmosphere. Combined with the homogeneous Hg0 oxidation experiment results, two domination reaction routes of Hg0 oxidation over VWTi catalysts in a fast SCR atmosphere were proposed. One was that the adsorbed Hg0 could react with the surface active species to form HgO. The other reaction route was a gaseous homogeneous route that the gaseous Hg0 could be oxidized directly to Hg(NO3)2 by gaseous NO2. Particularly, the gaseous homogeneous Hg0 oxidation process could notably weaken the inhibition effect of NH3 on Hg0 oxidation, thus improving the Hg0 oxidation activity of VWTi catalysts in a fast SCR atmosphere.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2021
·Vol. 28
·期 44
·62519-62529
·
IF 4.223
Chang Jingyi,Xiang Wenrui,Qu Ruijuan,Sun Cheng,Wang Zunyao,Zhu Feng,Huo Zongli
Bisphenol AF (BPAF), commonly used as a substitute for bisphenol A (BPA), is also an endocrine disruptor with cytotoxicity, neurotoxicity, genotoxicity, and biotoxicity. In this study, we found that BPAF could be effectively degraded by free chlorine. The second order rate constant of the reaction ranged from 1.67 to 126.67 M −1 ·s −1 in the pH range of 5.0–11.0. Nineteen products were detected by LC-Q-TOF-MS analysis, including chlorinated BPAF (i.e., mono/di/tri/tetrachloro-BPAF), 8 dimers, and 6 trimers. According to the identified products, two transformation pathways of electrophilic substitution and electron transfer are proposed. Humic acid (HA) could inhibit the degradation rate of BPAF due to its ability to reduce the reactive BPAF radical intermediates to the parent compound. The addition of low concentrations of Br − and I − accelerates the reaction rate of BPAF, due to the formation of HOBr and HOI with a higher oxidizing capacity. In seawater, BPAF degraded rapidly, and 16 new halogenated products were formed. Theoretical calculation shows that electrophilic substitution is more prone to occur at the ortho position of the hydroxyl group to form chlorinated products, while electron transfer tends to occur at the hydroxyl oxygen, resulting in the formation of BPAF radical and its subsequent coupling products.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Environmental Sciences
·
2024
·
IF 5.9
Xuan Liang,Jin Zhang,Juntai Tian,Zenghua Xie,Yue Liu,Peng Liu,Daiqi Ye
Herein, three supported catalysts, CuO/Al 2 O 3 , CeO 2 /Al 2 O 3 , and CuO-CeO 2 /Al 2 O 3 , were synthesized by the convenient impregnation method to reveal the effect of CeO 2 addition on catalytic performance and reaction mechanism for toluene oxidation. Compared with CuO/Al 2 O 3 , the T 50 and T 90 (the temperatures at 50% and 90% toluene conversion, respectively) of CuO-CeO 2 /Al 2 O 3 were reduced by 33 and 39 °C, respectively. N 2 adsorption-desorption experiment, XRD, SEM, EDS mapping, Raman, EPR, H 2 -TPR, O 2 -TPD, XPS, NH 3 -TPD, Toluene-TPD, and in-situ DRIFTS were conducted to characterize these catalysts. The excellent catalytic performance of CuO-CeO 2 /Al 2 O 3 could be attributed to its strong copper-cerium interaction and high oxygen vacancies concentration. Moreover, in-situ DRIFTS proved that CuO-CeO 2 /Al 2 O 3 promoted the conversion of toluene to benzoate and accelerated the deep degradation path of toluene. This work provided valuable insights into the development of efficient and economical catalysts for volatile organic compounds.
研究领域:
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER
·
2025
·
IF 4.5
Junjie Liu,Jianmin Wu,Qiwen Sun,Jiancheng Wang,Yan Sun
The high viscosity index poly-alpha-olefin was prepared by 1-decene polymerization under [EBIZrCl 2 /Al( i Bu) 3 /[Ph 3 C] + [B(C 6 F 5 ) 4 ] - system (EBI = rac-C 2 H 4 (1-Ind) 2 ), and its mechanism was investigated by in situ UV–Vis, 1 H NMR and ESI-MS. The results show that the kinematic viscosity at 100 °C (KV 100 ), viscosity index (VI) and yield of product reach to 336.3 cSt, 268 and 90.76 % under optimum reaction condition, wherein Zr/1-decene content, Al/Zr content, B/Zr content, reaction temperature and time are 10 −4 , 200, 2, 90 °C and 120 min, respectively. Meanwhile, temperature plays a crucial role in controlling the KV 100 and VI of product, with impact index of 55.43 % and 44.32 %, respectively. In situ UV–Vis, 1 H NMR, and ESI-MS analyses confirm the simultaneous generation of active (EBIZr-σ-polydecenyl cations) and inactive species (EBIZr-η 3 -(1-propyl-C 7 H 8 ) + ). The active and inactive species are generated through posing complexation to the terminal allyl of 1-decene and H 2 loss of EBIZr(u- i Bu) + , respectively. The second inactivate species (EBIZr-η 3 -(x-propyl-(3-x)-polydecenyl-C 3 H 3 ) + (x = 1 or 2)) can be activated by seizing isobutyl group in Al( i Bu) 3 . Subsequently, the polymer with an Al-capped saturated chain end is formed through chain migration. The polymerization process follows the reaction pathway: [1-decene]+[catalyst]→[active species]+[inactive species]. This is supported by the fact that all fitting curve of conversion versus time, 1-decene consumption and polymer generation conform to the Boltzmann (R 2 = 0.999). Based on those findings, a possible mechanism in ansa-zirconocene catalyzed polymerization of 1-decene is proposed.
研究领域:
高分子化学
·
催化化学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Na Li,Yuping Fan,Xianshu Dong,Qingxia Liu,Xiaomin Ma,Ruxia Chen
In this study, in order to improve the flocculation efficiency of natural organic flocculant in coal mine wastewater, guar gum (GG) and [2-(methacryloyloxy) ethyl] trimethyl ammonium chloride (DMC)were used to synthesize a type of graft copolymer of GG with DMC (GG-g-DMC) with flocculating function by free radical polymerization under ultraviolet (UV) light initiation conditions. Performance testing and structural characterization of the composites including FTIR, NMR, XRD, SEM, TG, and XPS were conducted to verify the synthesis of the graft polymer. The GG-g-DMC was applied to treat coal mine wastewater, according to the sedimentation index and the optimal flocculation solution was determined, and the flocculation settling mechanism was studied using focused beam reflectance measurement (FBRM), Zeta potentiometer and adhesion force meter. The results indicated that GG-g-DMC synthesis by UV-initiated polymerization was feasible and the settling effect increased significantly; 0.5 mg/g (s) GG-g-DMC 4 was excellent in all aspects, its sedimentation speed reached 20.64 cm/min, the light transmittance was 95.00%, and the compression layer thickness was 1.89 cm; the mechanism is mainly the synergy of charge neutralization, bridging, and improve hydrophobicity.
研究领域:
环境科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2025
·
IF 4.3
Shuang E,Zhao Gao,Xinran Cong,Chuang He,Lidan Gao,Zhenxing Yin
Nitrogen-doped carbon dots (NCDs) serve as promising green corrosion inhibitors for carbon steel in acidic environments. However, the influence of nitrogen doping levels on their inhibition performance remains unclear. This study synthesizes five NCDs with varying nitrogen contents (8.34 %, 10.98 %, 13.04 %, 18.52 %, and 19.64 %) through a controlled method and confirms their long-term colloidal stability. Corrosion inhibition efficiencies are evaluated in 1 mol/L HCl using electrochemical measurements. More importantly, the inhibition mechanism is elucidated from both molecular-level calculations and microscopic characterization. The results show a non-monotonic relationship between nitrogen content and inhibition efficiency, with NCDs-4 (18.52 % N) exhibiting the highest performance, reaching 95.27 % efficiency at 100 mg/L. Adsorption isotherm analysis, surface morphology characterization, and quantum chemical calculations reveal the inhibition mechanism. The superior performance of NCDs-4 is attributed to its balanced electron-donating ability and favorable molecular geometry, which promote strong parallel adsorption on the steel surface. This work clarifies the role of nitrogen content in modulating NCD performance and provides guidance for their rational design as corrosion inhibitors.
研究领域:
材料科学
·
腐蚀与防护
·
绿色化学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Dian Lv
In this paper, air-dried lake sludge was pretreated by ball milling, and then pyrolysed at 600°C to prepare lake sludge-derived ball milling biochar, and Fe 3 O 4 was loaded on lake sludge-derived ball milling biochar by chemical precipitation. Scanning electron microscopy-energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction were used to investigate and characterize the adsorbents. The results demonstrated that ball mill pretreatment and Fe 3 O 4 -loaded can effectively increase the content of O-containing groups in the adsorbent. The batch adsorption experiments revealed that Cd(II) removal followed the pseudo-second- order kinetic model and the Langmuir model. Additionally, the Cd(II) maximum adsorption by biochar (BC), MBBC and Fe 3 O 4 @MBBC was 31.33, 47.36 and 92.42 mg/g, respectively. The Cd(II) removal mechanisms were complexation, ion exchange, co-precipitation and electrostatic interaction. The Cd(II) removal efficiency on Fe 3 O 4 @MBBC was maintained at 91.35% after 5 adsorption– desorption experiments, indicating that Fe 3 O 4 @MBBC had the ability to be better applied for the removal of Cd(II)-containing wastewater.
研究领域:
环境科学
·
材料科学
·
水处理技术
✓ 已验证
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2011
·
IF 2.594
Jun Chen,Shumei Liu,Jianqing Zhao
A novel flame retardant containing silicon and caged bicyclic phosphate groups, tri(2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane-1-oxo-4-hydroxymethyl) phenylsilane (TPPSi) was successfully synthesized. The chemical structure of TPPSi was characterized by FTIR, 1 H NMR and 31 P NMR. The application of TPPSi (25 wt%) as a flame retardant in polyamide 6 (PA6) not only gains satisfied flame retardancy and smoke suppression, but also retains the high toughness and inherent appearance of pure PA6. The influence of TPPSi on the decomposition pathway of PA6 was discussed based on TG–FTIR and FTIR analysis. The interaction between TPPSi and PA6 at high temperature alters the decomposition pathway of PA6 resulting in the formation of the residue containing phosphorus and silicon. The heat and smoke release behaviors at different external heat fluxes were measured by cone calorimeter, and the fire residue was analyzed by SEM–EDX. The condensed phase action resulting from the barrier effect of residue is proposed to be the major flame retardancy mechanism of TPPSi in PA6, with the fuel reduction action as the minor.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Jing Wang,Tong Zheng,Chen Cai,Yanxiang Zhang,Huiling Liu
The oxidation of ethanethiol (C 2 H 5 SH), as a representative odorous pollutant, by ferrate (Fe(VI)) in aqueous alkaline solution was investigated to understand its kinetics, stoichiometry, and reaction pathways. The reaction kinetics and fraction of different intermediates were found highly dependent on pH. The reaction behaved as a 5/2-order reaction in a pH range of 8.0–10.0, and a second-order reaction in a pH range of 10.5–12.0. The rate constants decreased with increased pH, and the speciation of Fe(VI) and C 2 H 5 SH during the reaction were further discussed. C 2 H 5 SH was finally oxidized to nonvolatile and odorless sulfonic acid (C 2 H 5 SO 3 H) with the intermediates of sulfinic acid (C 2 H 5 SO 2 H) and disulphide (C 2 H 5 SSC 2 H 5 ). A plausible mechanism involving two competing reactions for C 2 H 5 S radicals was proposed to explain the pH-dependent reaction order. In addition, kinetics and products of C 2 H 5 SH degradation by Fe(VI) were compared with other oxidants (O 3 , chlorine, ClO 2 , KMnO 4 , H 2 O 2 , and OH). Our results provided a deep understanding of C 2 H 5 SH degradation by Fe(VI) in aqueous alkaline solution.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2015
·Vol. 133
·期 6
·
IF 1.768
Maolin Li,Yuhua Zhong,Zheng Wang,Andreas Fischer,Florian Ranft,Dietmar Drummer,Wei Wu
A novel flame-retardant composite was prepared by introducing a phosphorus-nitrogen flame retardant and DOPO-SiO 2 into PA6. DOPO-SiO 2 was synthesized successfully in a one-step process. PA6/OP1314/DOPO-SiO 2 achieved a UL 94 V-0 rating with an LOI value of 31%. The maximum mass loss rate of decomposition decreased significantly and char residue increased to 11.6 wt % compared with that of pure PA6. The compacted and dense char was formed due to the combination of the P-N flame retardant and DOPO-SiO 2 . The complex viscosity of PA6/OP1314/DOPO-SiO 2 increased considerably which tend to prevent the dripping phenomenon. The flame-retardant mechanism of PA6/OP1314/DOPO-SiO 2 was also investigated by Fourier transform infrared spectroscopy FTIR at different temperatures and the pyrolysis products were investigated by pyrolysis gas chromatography/ mass spectrum (Py-GC/MS). It was assumed that DOPO-SiO 2 and the hypophosphite of OP1314 possess excellent flame retardancy during the gaseous phase. Meanwhile, melamine and phosphate reacted with the pyrolytic products of PA6 to protect the matrix during the condensed phase. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133 , 42932.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Zhipeng He,Huichao Liu,Shuo Zhang,Jinglong Yang,Chi Jiang,Muwei Ji,Jiali Yu,Mingliang Wang,Caizhen Zhu,Jian Xu
Cyclization reaction is a crucial step during the heat treatment process of polyacrylonitrile (PAN)-based carbon fibers (CFs). In this work, in situ infrared spectroscopy and two-dimensional (2D) correlation spectroscopy are employed for the investigation of the cyclization mechanisms of PAN and poly(acrylonitrile-co-ethylenesulfonic acid) [P(AN-co-ESA)] copolymer during different temperature treatments under air atmosphere. The cyclization reaction of PAN was promoted by an acknowledged free radical mechanism. The cyclization reaction of P(AN-co-ESA) copolymer was promoted by an autocatalytic cyclization mechanism. A key step during this process was that the association structures generated by the interaction of hydrogen bond under heat treatment and the bond of S═O change before the cyclization structures composed of C═C and C═N bonds. The new insight about the cyclization mechanism of P(AN-co-ESA) copolymer was verified by Fourier transform infrared spectroscopy and 2D correlation analysis. It is useful for further studies of the comonomer in PAN copolymers as a precursor of CFs.
研究领域:
材料科学
·
化学工程
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）