Atmosphere
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2022
·Vol. 13
·期 2
·333
·
IF 3.11
Chao Wang,Lingdong Kong,Shengyan Jin,Lianghai Xia,Jie Tan,Yuwen Wang
Soot and aged soot are often found to be mixed with atmospheric particles, which inevitably affect various atmospheric heterogeneous reactions and secondary aerosol formation. Previous studies have investigated the heterogeneous reaction of NO2with different types of soot, but there are few studies on the heterogeneous reaction of NO2with mixtures containing diesel soot (DS) or aged DS and mineral dust particles. In this study, the effects of DS and aged DS on the heterogeneous reaction of NO2on the surface of γ-Al2O3were investigated via in-situ diffuse reflectance infrared Fourier transform spectrometry (DRIFTS). The results showed that the DS or DS n-hexane extract significantly inhibited the formation of nitrate on γ-Al2O3particles and promoted the formation of nitrite. At 58% RH, with the increase of DS or DS n-hexane extract loading amount, the effect of DS or DS n-hexane extract on the formation of nitrate changed from promotion to inhibition, but DS or DS n-hexane extract always promoted the formation of nitrite. The results also showed that light was conducive to the formation of nitrate on the DS-γ-Al2O3or DS-n-hexane extract-γ-Al2O3particles. Furthermore, the influence of soot aging on the heterogeneous reaction of NO2was investigated under light and no light. In the dark, O3-aged DS-γ-Al2O3or O3-aged DS-n-hexane extract-γ-Al2O3firstly inhibited the formation of nitrate on the mixed particles and then promoted it, while the effect of aged DS on nitrite formation was complex. Under light, the O3-aged DS-γ-Al2O3firstly promoted the formation of nitrate on the mixed particles and then inhibited it, while the O3-aged DS-n-hexane extract-γ-Al2O3promoted the formation of nitrate on the mixed particles. Our results further showed that the production of nitrate on the O3-aged particles under light or no light was greater than that of the UV-nitrate-aged particles. This study is helpful to deeply understand the atmospheric chemical behavior of soot and the heterogeneous conversion of atmospheric NO2.Keywords:soot;NO2;heterogeneous reaction;aged soot;γ-Al2O3
研究领域:
大气化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2022
·Vol. 12
·期 6
·596
·
IF 4.501
Silun Zhu,Shuying Shi,Xinhua Zheng,Xinqiang Wang,Gang Yu,Yonggang Jiang,Jian Feng,Luyi Zhu,Guanghui Zhang
In this paper, cerium was incorporated into polyhydroxyltriacetictin (PHTES) using the sol-gel method combined with electrospinning technology to prepare a series of composite oxide fiber catalysts SnxCe1−xO2in different proportions. The structures and soot catalytic activities of SnxCe1−xO2fibers were studied under loose contact conditions. When Ce entered the crystal lattice of SnO2, the structural symmetry of the SnO2was destroyed, which inhibited the crystallization and grain growth of the fiber, and fiber catalysts with a larger specific surface area were obtained. Moreover, the introduction of Ce improved the number of oxygen vacancies and redox ability of the catalyst, thus promoting the catalytic activity of the catalyst for soot particles. In particular, among them, the Sn0.7Ce0.3O2fiber catalysts had the strongest catalytic oxidation ability regarding soot particles and could oxidize soot particles at a lower temperature and faster catalytic rate. The results of the temperature-programmed oxidation of Sn0.7Ce0.3O2fiber catalyst, conducted three times under the same conditions, were basically consistent, indicating that the experimental results are reliable and repeatable. In addition, the Sn0.7Ce0.3O2fiber catalyst showed good cycle stability.Keywords:electrospinning;SnxCe1−xO2fiber catalyst;soot combustion
研究领域:
材料科学
·
环境催化
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2024
·Vol. 14
·期 2
·135
·
IF 3.8
Baofang Jin,Yuxin Liu,Yue Ma,Zhenguo Li,Kaixiang Li,Shuang Liu,Rui Ran,Xiaodong Wu
A series of Ag-modified manganese-mullite (SmMn2O5) catalysts with different Ag contents (1, 3, and 6 wt.%) were prepared via a citric acid sol–gel method for catalytic soot oxidation. The catalysts were characterized by powder X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), Raman spectroscopy, transmission electron microscopy (TEM), high-resolution transmission electron microscopy analysis (HRTEM), X-ray photoelectron spectroscopy (XPS), and H2temperature-programmed reduction (H2-TPR). The soot oxidation activity of the mullite was significantly promoted by the addition of silver and affected by the loading amount of the metal. Herein, the influences of silver loading on the metal size distribution and its interactions with the mullite were studied. Based on these characterizations, a possible soot oxidation reaction mechanism was proposed for silver-modified SmMn2O5.
研究领域:
催化材料
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Dehua Zeng,Chen Yang,Ziqing Huang,Yanjun Liu,Sijia Liu,Zhiyu Zhang,Weilin Huang,Zhi Dang,Chengyu Chen
Heteroaggregation between polystyrene nanoplastics (PSNPs) and soot nanoparticles (STNPs) in aquatic environments may affect their fate and transport. This study investigated the effects of particle concentration ratio, electrolytes, pH, and humic acid on their heteroaggregation kinetics. The critical coagulation concentration (CCC) ranked CCC PSNPs > CCC PSNPs-STNPs > CCC STNPs , indicating that heteroaggregation rates fell between homoaggregation rates. In NaCl solution, as the PSNPs/STNPs ratio decreased from 9/1 to 3/7, heteroaggregation rate decreased and CCC PSNPs-STNPs increased from 200 to 220 mM due to enhanced electrostatic repulsion. Outlier was observed at PSNPs/STNPs= 1/9, where CCC PSNPs-STNPs = 170 mM and homoaggregation of STNPs dominated. However, in CaCl 2 solution where calcium bridged with STNPs, heteroaggregation rate increased and CCC PSNPs-STNPs decreased from 26 to 5 mM as the PSNPs/STNPs ratio decreasing from 9/1 to 1/9. In composite water samples, heteroaggregation occurred only at estuarine and marine salinities. Acidic condition promoted heteroaggregation via charge screening. Humic acid retarded or promoted heteroaggregation in NaCl or CaCl 2 solutions by steric hindrance or calcium bridging, respectively. Other than van der Waals attraction and electrostatic repulsion, heteroaggregation was affected by steric hindrance, hydrophobic interactions, π − π interactions, and calcium bridging. The results highlight the role of black carbon on colloidal stability of PSNPs in aquatic environments.
研究领域:
环境科学
·
胶体化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2018
·
IF 11.698
Fan Fang,Nengjie Feng,Lei Wang,Jie Meng,Geng Liu,Peng Zhao,Pengfei Gao,Jing Ding,Hui Wan,Guofeng Guan
Perovskite-type macro/mesoporous nanotube shows large specific surface area and high utilization of catalytic sites, which gives rise to the enhancement of catalytic activity and broaden their application. In this work, perovskite-type La 1-x K x FeO 3-δ nanotubes were prepared for efficient soot oxidation by a simple electrospinning technique following calcination. The as-prepared samples were characterized by XRD, FI-IR, FE-SEM, TEM, XPS, N 2 adsorption-desorption, H 2 -TPR and O 2 -TPD techniques to investigate the physical-chemical properties. A certain amount of K + doped in to LaFeO 3-δ nanotubes sample could inhibit the growth of crystallites during the calcination at a high temperature, which could prevent the destruction of macro/mesoporous tubular structure and contribute to the more contact between soot particles and active sites. Meanwhile, it could also bring about the higher oxygen vacancy density responsible for the enhancement of redox abilities. However, excessive doping of K + could lead to the collapsing of macro/mesoporous tubular structure, ascribable to the formation of low-melting compounds or eutectics with other components of the catalyst, which would have a negative influence on the catalytic performance. The performance for soot catalytic oxidation was evaluated in a temperature programmed oxidation device using O 2 (without or with NO) as oxidant. Among the as-prepared catalysts, the well-structured La 0.8 K 0.2 FeO 3-δ nanotubes catalyst is the best candidate for soot removal.
研究领域:
材料科学
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环境催化
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Fan Fang,Nengjie Feng,Peng Zhao,Chong Chen,Xue Li,Jie Meng,Geng Liu,Li Chen,Hui Wan,Guofeng Guan
The PrBa 0.5 Sr 0.5 Co 0.2 Fe 1.8 O 5+δ double perovskite porous nanotubular webs are prepared by a simple electrospinning technique following calcination. It shows better catalytic activity compared with the bulk PrBa 0.5 Sr 0.5 Co 0.2 Fe 1.8 O 5+δ prepared by citrate method, due to its larger specific surface area and higher utilization of active sites. On basis of this, introducing multiple active sites is conducive to enhancing the catalytic activity. In this work, the PrBa 0.5 Sr 0.5 Co 0.2 Fe 1.8 O 5+δ double perovskite porous nanotubular webs are further reduced at 750 °C in a 10% H 2 /N 2 gas flow, which can give rise to the in situ exsolution of Co core-shell nanoparticles and obtain double active sites. Meanwhile, series of related catalysts are also prepared for comparison, and the physicochemical properties of these catalysts are studied by a lot of characterization techniques. The catalytic performance for soot combustion is evaluated by a temperature programmed oxidation test, which can simulate the soot combustion process. Turn of frequency (TOF) and activation energy ( E a ) are calculated by isothermal studies to further evaluate the activity of the as-prepared catalyst. Among all the prepared catalysts, the PrBa 0.5 Sr 0.5 Co 0.2 Fe 1.8 O 5+δ porous nanotubular webs after reductive treatment at 750 °C in H 2 atmosphere exhibits the best catalytic activity for soot combustion, showing the lowest activation energy and the highest TOF values. Furthermore, its catalytic activity is significantly promoted compared with the bulk-type catalyst. Firstly, it may be associated with the synergistic effects of sufficient Co core-shell nanoparticles and oxygen vacancies in double perovskite functioned as active sites. Secondly, the structure of porous nanotubular webs can make full use of these active sites.
研究领域:
材料科学
·
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL POLLUTION
·
2023
·
IF 8.9
Tengteng Shi,Baoqiang Xu,Jilin He,Xinyang Liu,Zibin Zuo
The efficient release of arsenic in copper smelting flue dust (CSFD) with complicated production conditions and composition under the premise of environmental safety is difficult for the copper smelting industry. The vacuum environment is conducive to the volatilization of low-boiling arsenic compounds , which is beneficial to the physical process and chemical reaction of increasing the volume. In the present study, combined with thermodynamic calculations, the roasting process of pyrite and CSFD mixed in proportion in vacuum was simulated. Additionally, the release process of arsenic and the interaction mechanism of the main phases were performed in detail. The addition of pyrite facilitated the decomposition of stable arsenate in CSFD into volatile arsenic oxides. The results indicated that exceeding 98% of arsenic in CSFD volatilized into the condenser, while the arsenic content in the residue was reduced to 0.32% under optimal conditions. Pyrite could reduce the oxygen potential during the chemical reaction with CSFD, reacting with sulfates in CSFD to convert into sulfides and magnetic iron oxide (Fe 3 O 4 ) simultaneously, and Bi 2 O 3 would be transformed into metallic Bi. These findings are significant for developing arsenic-containing hazardous waste treatment routes and the application of innovative technical approaches.
研究领域:
冶金工程
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2022
·
IF 8.035
Hua Yang,Xingchuan Yang,Jieyu Xiao,Yi Yu,Li Xu,Xingang Li,Chunmei Cao,Guoji Liu
Highly active spinel-derived monolithic catalysts loading Ag (xAg/NiCo-NS) have been successfully designed and synthesized and used to catalytic soot elimination. The crossed macro-porous of NiCo 2 O 4 nanosheets and the three-dimensional porous structure of Ni foam not only provides a convenient gas mass transfer channel, but also provides a large number of contact points between soot and catalyst. After loading Ag on the NiCo-NS, the catalytic performance for soot oxidation is improved remarkably. Among the xAg/NiCo-NS catalysts, the 4.5Ag/NiCo-NS sample has the highest catalytic performance with the lowest T 50 (333 °C), which is 50 °C lower than that of the NiCo-NS catalyst and lower than that of other prove metal catalysts (Pt/Pd/Au) in the atmosphere of 500 ppm NO/10 % O 2 /N 2 . The metal-support interaction between Ag and NiCo-NS weakens the Co-O bond, increases the amount of surface oxygen vacancies and improves the intrinsic activity determined by turnover frequency (TOF) of the catalyst. Moreover, Ag can also adsorb and activate gaseous oxygen to produce the low-temperature active oxygen species (O 2 − ), which can promote the soot combustion in the low temperatures. Based on the catalytic performance for soot oxidation and activation Energy (Ea), the reaction paths for the catalytic combustion of soot on Ag/NiCo-NS are identified.
研究领域:
材料科学
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环境科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Longwen Chen,Feng Liu,Xiaoqian Li,Qiuzhen Tao,Zhaoqin Huang,Qi Zuo,Yanwu Chen,Tan Li,Mingli Fu,Daiqi Ye
Metal oxide-oxide interface on supported catalyst has been rarely studied due to the complex interfacial structure and synthetic challenge. Herein, different Ag-supported CeO 2 /Co 3 O 4 samples with various covered-state of CeO 2 were prepared for catalytic soot oxidation. In comparison, catalytic activity was significantly improved by grafting CeO 2 on Co 3 O 4 , in which the best performing Ag/CoCe-2 exhibited remarkable catalytic performance towards soot oxidation with a T 50 of 290.5 ℃ under 10 % O 2 /N 2 . Catalyst characterization investigated by Scanning Electron Microscope (SEM), quasi in-situ X-ray Photoelectron Spectroscopy (XPS), in-situ Raman, etc. revealed that this outstanding promotion in catalytic activity can be principally ascribed to the formation of the CeO 2 /Co 3 O 4 interface. An appropriate CeO 2 dosage maximized the contact and interaction between Co 3 O 4 and CeO 2 , resulting in the largest CeO 2 /Co 3 O 4 interface featured with abundant generated superoxide species and activated surface lattice oxygen. Density functional theory (DFT) calculations were also carried out for the oxygen vacancy formation energy, Gibbs free energy, etc. In presence of the CeO 2 /Co 3 O 4 interface, a charge density redistribution around the adsorbed reactants at oxygen vacancies could be formed, owing to the efficient charge transfer enhanced by the electron-appealing effect. The change in electronic structure favored reducing the oxygen vacancy formation energy and boosting the lattice oxygen activation induced by the hybridized Co-O-Ce bonds, finally lowering the adsorption and activation barriers for reactive species and accelerating the reaction kinetics.
研究领域:
材料科学
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催化化学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Fu Yang,Li-an Xing,Kwame Nana Opoku,Hongyao Zhao,Zhenxiao Wang,Ruiting Ni,Qiang Gao,Zengjing Guo,Feng Zeng,Aihua Yuan,Jianming Pan
The utilization of ambient low-pressure CO 2 adsorption for carbon neutrality initiatives holds great potential. However, conventional liquid amine absorption methods for CO 2 capture are plagued by high energy consumption and equipment corrosion issues. In this study, we present a novel approach using industrial waste silica fume (SF) as a precursor and tetraethylenepentamine (TEPA) as a chemical modifying agent to efficiently synthesize low-cost mesoporous solid amine adsorbents within the waste-derived mesoporous powder sorbents (MPS) series. Employing the static adsorption technique, the impact of both adsorption temperature and amine loading on the CO 2 adsorption efficacy was comprehensively investigated. The optimized sample, MPS-TEPA-30, demonstrated a superior CO 2 adsorption capacity, achieving 2.22 mmol g −1 at 323 K and 1 bar, a significant 6.8-fold increase compared to the unmodified MPS material (0.326 mmol g −1 ). Additionally, MPS-TEPA-30 demonstrated notable performance advantages, surpassing SBA15-TEPA-30 and MCM41-TEPA-30 with near 1.49- and 2.12-fold increases in adsorption capacity, respectively. Impressively, MPS-TEPA-30 exhibited remarkable adsorption ability beyond 1.5 mmol g −1 at ultralow pressures (<0.01 bar), suggesting its potential for ambient ultralow-pressure CO 2 capture. Moreover, MPS-TEPA-30 showed exceptional stability over multiple adsorption–desorption cycles, with only a marginal 6 % decrease in CO 2 capture efficiency after the seventh cycle. Thermogravimetric analysis confirmed the robust thermal stability of the amine-functionalized adsorbent (∼473 K), rendering it suitable for high-temperature adsorption–desorption processes. The Ideal Adsorbed Solution Theory (IAST) equation predicted an excellent adsorption selectivity of 1600 for the CO 2 /N 2 (1:1) mixture at 323 K and 10 mbar, underscoring the promising prospects of MPS-TEPA-30 in CO 2 capture and selective separation applications from ambient condition.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2021
·
IF 6.986
Yue Lin,Xiu Huang,Yongchun Liu,Dong Cao,Dawei Lu,Zeming Feng,Qian Liu,Zhenyu Lin,Guibin Jiang
Soot is ubiquitous and has large detrimental effects on climate, air quality, and human health. However, identification of soot in carbonaceous media is very challenging due to its nanoscale carbon nature and complex sources. Due to the shortage in the methodology, until now, the fate and health effect of soot particles after inhalation are still poorly understood. Here, we report a new method for label-free identification, quantification, and imaging of soot particles in complex media based on laser desorption/ionization mass spectrometry fingerprinting. We found that soot particles from different origins and with different morphologies showed highly consistent mass spectral fingerprints deriving from peak ratios of small carbon cluster anions (C2––C10–), which enabled both accurate quantification of soot in fine particulate matter (PM2.5) samples and label-free imaging of soot particles in biological media. By using this technique, we tracked and imaged the suborgan distribution of soot particles in mice after exposure to PM2.5. The results showed that the lung is the main target organ for short-term inhalation exposure to soot particles. This study helps to better understand the inhalation toxicology of soot and also provides a practical novel methodological platform for identification, tracing, and toxicological studies of elemental carbon-based nanomaterials.
研究领域:
环境科学
·
分析化学
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CATALYSIS
·
2023
·
IF 7.3
Yuanfeng Li,Tian Qin,Yaxiao Ma,Jing Xiong,Peng Zhang,Kezhen Lai,Xi Liu,Zhen Zhao,Jian Liu,Liwei Chen,Yuechang Wei
Herein, a series of Co x -CeO 2 nanosheet catalysts were elaborately synthesized by a one-step hydrothermal method. The CeO 2 microsphere with crossed nanosheets can improve the soot-catalyst contact efficiency and the lattice substitution of Co ions for cerium sites in CeO 2 results in the oriented lattice bending of Co-CeO 2 nanosheets for improving adsorption/activation properties of NO and O 2 . Co 2 -CeO 2 catalyst displays the highest H 2 O-tolerance activity ( T 50 = 334 °C, TOF = 1.32 h −1 ) and excellent stability during soot oxidation in the presence of H 2 O. Combined with characterizations and DFT calculations, the mechanism was proposed: the active edge sites located at the oriented lattice bending of Co-CeO 2 nanosheets can activate surface oxygen and gaseous O 2 , and active oxygen species can boost NO oxidation to NO 2 , which is a crucial step of NO x -assistant catalytic mechanism for soot oxidation. It provides a promising way for the rational design of high-performance non-noble metal catalysts for soot oxidation in practical applications.
研究领域:
催化
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环境科学
·
材料科学
✓ 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）