JOURNAL OF CATALYSIS
·
2022
·
IF 8.047
Leisheng Che,Jinqiu Guo,Zhiwei He,Hongbo Zhang
We report here that the reduction degree of the metal at the catalytic interface dominates the reactivity of acetylene hydrogenation, mainly in terms of turnover rates (TORs) and activation energies, which could certainly cause the switch of kinetically relevant steps (KRS) from “C 2 H 3 *+H*” over Ce(OH)SO 4 ·xH 2 O dispersed Pd catalyst to “C 2 H 4 *+H*” elementary step over Pd/CeO 2 . Besides, a compact kinetic model has been established to describe the reaction process and the dissociative mechanism was confirmed by H 2 /D 2 exchange experiment. Meanwhile, the rate-determining step (RDS) and the main adsorbed species of the reaction were confirmed by systematic kinetic studies as well as in-situ FTIR analysis. More importantly, with the aid of parity fitting and gas isothermic adsorption analysis, the energetic relationship among the steps along with the acetylene hydrogenation is quantitatively described, which provides a good support and complement for the previous research, and helps researchers build up advanced reaction systems.
研究领域:
化学动力学
·
催化
·
表面化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Yu-Jia Nong,Yi-Lin Zhang,Uwe Hübner,Wen-Long Wang,Qian-Yuan Wu,Nan Huang,Jörg E. Drewes,Hong-Ying Hu
Vacuum-UV (VUV) (wavelength 185 nm)/ UV (wavelength 254 nm) are applied to improve performances of UV-based advanced oxidation processes. However, the improvements were strongly affected by water depth because of poor VUV transmittance in water. In this study, VUV/UV and peroxydisulfate (PDS) were used to degrade carbamazepine. More SO 4 •− oxidation occurred in VUV/UV/PDS than VUV/UV with similar • OH oxidation occurring. The additional SO 4 •− oxidation could be caused by VUV/PDS in superficial water or UV/PDS in deeper water. The synergistic factor for VUV/UV/PDS processes relative to VUV/UV and UV/PDS processes was 1.32. VUV/UV/PDS performances were affected by competition for photon absorption by dissolved organic matter (32–58 % inhibition), radical quenching by CO 3 2− /HCO 3 − and NO 3 − , and conversion of • OH and SO 4 •− into reactive chlorine species by Cl − . Radical probe experiments and steady-state kinetic modeling simulations indicated that 34 %, 25 %, and 40 % of carbamazepine degradation occurring in 2-cm-deep bulk solution was due to • OH oxidation through VUV/H 2 O, SO 4 •− oxidation through VUV/PDS, and SO 4 •− oxidation through UV/PDS, respectively. Contribution of VUV-driven processes decreased with increasing water depth and became equivalent to contribution of 3.5-cm-deep UV-driven processes, which indicated the importance of optimizing water depth in VUV/UV-advanced oxidation process reactors.
研究领域:
环境科学
·
化学工程
·
水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2023
·Vol. 30
·期 30
·75595-75609
·
IF 5.8
Jiang Mengyun,Xu Zhongjun,Zhang Tingting,Zhang Xirong,Liu Ying,Liu Peng,Chen Xiaochun
In this work, FeS supported SBA-15 mesoporous silica catalyst (FeS@SBA-15) was synthesized successfully, characterized and first applied to persulfate (PS) activation for the degradation of imidacloprid in wastewater. The as-prepared 3.5-FeS@SBA-15 presented an impressive imidacloprid removal efficiency of 93.1% and reaction stoichiometric efficiency (RSE) of 1.82% after 5 min, ascribed to the synergetic effects of improved FeS dispersion and abundant surface sites by SBA-15. Electron paramagnetic resonance spectra and quenching experiments proved that both SO 4 ·- and ·OH were produced in FeS@SBA-15/PS system, and SO 4 ·- played a dominant role in the degradation process. The S 2- can accelerate the cycling of Fe(III)/Fe(II) during activation and increase the steady-state concentration of Fe(II). More importantly, the constructed heterogeneous system exhibited an efficient and stable catalytic activity over a wide range of pH (3.0-9.0), temperature (283K-313K), inorganic ion (NO 3 - ) and humic acid (1-20 mg/L). Moreover, the density functional theory calculations were conducted to predict the potential reaction sites of imidacloprid. Based on eighteen identified intermediates, four main degradation pathways were proposed: hydroxylation, dechlorination, hydrolysis, and the ring cleavage of the imidazolidine. ECOSAR analysis indicated hydroxylation and dechlorination played a key role in the detoxification of the formed compounds. These findings would provide new insights into the application of FeS@SBA-15 catalyst in wastewater treatment and the removal mechanism of imidacloprid from wastewater.
研究领域:
环境科学
·
催化
·
废水处理
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
HYDROMETALLURGY
·
2025
·
IF 5.3
Yanfei Fan,Dandan Gao,Dongdong Li,Dewen Zeng
Alum is an important intermediate for the extraction and purification of Cs or Rb chemicals, due to its excellent separation ability for Cs, Rb and K. Although the solubility sequence K-alum > Rb-alum > Cs-alum has been well known, the separation factors among Cs, Rb and K during the formation of alum have not been determined. The formation of solid solution of alum controls the Cs or Rb content and Cs/Rb/K ratio in the sequentially precipitated Cs, Rb and K alums. In this study, the thermodynamic equilibrium separation factors were determined from the solid solution-aqueous solution equilibrium data of the two mixed alum systems: (i) RbAl(SO 4 ) 2 , CsAl(SO 4 ) 2 , and H 2 O, and (ii) KAl(SO 4 ) 2 , RbAl(SO 4 ) 2 and H 2 O. The separation factor β Cs/Rb varied from 48 to 2 with the increase of the Rb/Cs ratio in system (i), and β Rb/K varied from 22 to 0.2 with the increase of the K/Rb ratio in system (ii). This suggests that the purification of Cs or Rb using alums is more efficient from raw materials containing high Cs/Rb or Rb/K ratio than that from low Cs/Rb or Rb/K ratio. In kinetic studies, the apparent separation factors β Cs/Rb and β Rb/K were highly affected by the recrystallization process of cooling or non-cooling and the initial composition of raw alum, showing asymmetric kinetic intensification. The separation factors β Cs/Rb or β Rb/K obtained in the “dissolution by heating and crystallization by cooling (DHCC)” process for the raw alum with high initial Cs/Rb or Rb/K molar ratio is several times larger than the equilibrium value expected from thermodynamics. Finally, CsAl(SO 4 ) 2 and RbAl(SO 4 ) 2 with a metal-based purity of 99.97 % and 99.94 %, respectively, were obtained by using the DHCC process 3–4 times.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Xudong Gong,Qiang Tian,Jiebiao Li,Ju Wang,Minhao Yan,Mark J. Henderson
Incorporation of fission products in spent nuclear fuel is of interest in the frame of safe storage of high-level nuclear waste in a deep geological repository. Uranyl oxyhydroxide films were grown on silicon wafer to represent the corrosion product formed on the surfaces of the fuel. Films were obtained by hydrolysis of uranyl ions (9 mM) in mild conditions (≤60 °C) using either Mg(OH) 2 , raw brucite, La(OH) 3 , or NH 4 OH to control the solution pH to ≈ 5.0. To identify the mineral phases we used the grazing-incidence X-ray technique. Atomic force microscopy data indicated that the surfaces of metaschoepite films prepared using either Mg(OH) 2 or brucite at 50 °C for 3 h were self-affine fractal ( D f = 2.5). The concentration (wt.%) of reactant ions detected in a metaschoepite film after reaction at 70 °C for three days as determined by X-ray fluorescence was: La (8.90) > Nd (5.6) > Ce (3.2) > Eu (2.5) > Pb (0.7) > Sr (0.14). Metaschoepite and sodium uranate hydrate were identified in a film formed in Cl-SO 4 -Na type groundwater from the Beishan area (China), the preselected area of a radioactive waste disposal repository.
研究领域:
核废料管理
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2022
·
IF 7.336
Fengyue Zhao,Juan Xiao,Shipeng Geng,Yi Wang,Panagiotis Tsiakaras,Shuqin Song
Fe 3+ /Fe 2+ interconversion is one of the key factors for heterogeneous electro-Fenton degradation of organic pollutants. In this study, MIL-101Fe-derived carbon wrapping Fe 7 S 8 nanocomposite (Fe 7 S 8 /C-1-600) exhibits outstanding rhodamine B (RhB) degradation ability with extremely low iron leaching and high recyclable degradability within 60 min in a wide pH range. Moreover, Fe 7 S 8 /C-1-600 presents a much higher activity for RhB degradation than Fe 3 O 4 counterpart without sulfidation, which could be mainly attributed to the accelerated Fe 3+ /Fe 2+ cycling by iron with both multiple valences (Fe 0 , Fe 2+ , and Fe 3+ ) and sulfur species (S 2− and S 2 2− ) of the catalyst. The enhancement of H 2 O 2 adsorption and activation into OH on Fe 7 S 8 surface is confirmed by density functional theory calculations with respect to that on Fe 3 O 4 . Interestingly, SO 4 · − can be generated by reacting S 2 2− with dissolved O 2 and subsequently converted into ·OH, which further facilitates RhB degradation. These findings may shed a new insight into the potential application of metal sulfides for wastewater treatment.
研究领域:
环境科学
·
化学工程
·
材料科学
·
水处理
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2017
·
IF 4.208
Ziying Wang,Yisheng Shao,Naiyun Gao,Xian Lu,Na An
Degradation of diethyl phthalate (DEP) by ultraviolet/persulfate (UV/PS) process at different reaction conditions was evaluated. DEP can be degraded effectively via this process. Both tert-butyl (TBA) and methanol (MeOH) inhibited the degradation of DEP with MeOH having a stronger impact than TBA, suggesting sulfate radical ( ) and hydroxyl radical (HO ) both existed in the reaction systems studied. The second-order rate constants of DEP reacting with and HO were calculated to be ( 6.4 ± 0.3 ) × 10 7 M −1 s −1 and ( 3.7 ± 0.1 ) × 10 9 M −1 s −1 , respectively. To further access the potential degradation mechanism in this system, the pseudo-first-order rate constants (k o ) and the radical contributions were modeled using a simple steady-state kinetic model involving and HO . Generally, HO had a greater contribution to DEP degradation than . The k o of DEP increased as PS dosages increased when PS dosages were below 1.9 mM. However, it decreased with increasing initial DEP concentrations, which might be due to the radical scavenging effect of DEP. The k o values in acidic conditions were higher than those in alkaline solutions, which was probably caused by the increasing concentration of hydrogen phosphate (with higher scavenging effects than dihydrogen phosphate) from the phosphate buffer as pH values rose. Natural organic matter and bicarbonate dramatically suppressed the degradation of DEP by scavenging and HO . Additionally, the presence of chloride ion (Cl − ) promoted the degradation of DEP at low Cl − concentrations (0.25–1 mM). Finally, the proposed degradation pathways were illustrated.
研究领域:
环境化学
·
水处理
·
高级氧化过程
·
污染物降解
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Liyuan Wu,Pengpeng Guo,Xin Wang,Haiyan Li,Angzhen Li,Kaiyu Chen
Peroxymonosulfate (PMS) activation methods have attractive advantages in advanced oxidation process (AOPs) due to their powerful ability of directly or indirectly generating various reactive oxygen species (ROS). Herein, trace amount of Fe(III) ions were added into the commercial-CoS 2 /PMS system to improve the CoS 2 /PMS decomposition for organics removal. The organics removal efficiency could reach >90% towards methylene blue (MB), diclofenac sodium (DCF), sulfamethoxazole (SMX) and bisphenol A (BPA) in the CoS 2 /Fe(III)/PMS system, with the kinetic apparent rate constant k obs of 0.141, 0.206, 0.247 and 0.091 min −1 , respectively. The synergistic effect between Fe(III) ions and sulfur-vacancies on CoS 2 for PMS degradation were revealed for the first time in cobalt sulfides/PMS system. Quenching experiments and ESR analysis proved that 1 O 2 was the major ROS and was produced mainly by the hydrolysis of SO 5 • – . Besides, the high degradation efficiency was obtained by the contribution of SO 4 • – and • OH. Electron spin–resonance spectroscopy (ESR), cyclic voltammetry (CV) and Raman spectrum data revealed that the addition of Fe(III) ions could optimize the intensity of sulfur vacancies on the CoS 2 surface, which hindered the PMS reduction ability of Co(II), but accelerated the PMS oxidation to form 1 O 2 . The degradation path of MB was analyzed by liquid chromatograph-mass spectrometer (LC-MS). The mechanism studies speculated that the sulfur vacancies of CoS 2 provided the binding sites for Fe(III) ions with Co(II), which facilitated the PMS activation by Co(III).
研究领域:
环境化学
·
催化
·
水处理
·
高级氧化过程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS ES&T Engineering
·
2024
·
IF 7.4
Caihong Liu,Xihui Jiang,Zhiqiang Sun,Rui Gao,Min Wang,Qiang He,Jun Ma
Catalytic membranes that enable simultaneous micropollutant degradation during oil/water separation have emerged as a promising candidate for treating complex emulsified oily wastewater. However, this hybrid system suffers from membrane fouling and subsequent radical quenching. Herein, we overcome these challenges by developing a novel hierarchical filtration-catalysis ceramic membrane to achieve efficient gradient decontamination. This membrane comprises a top hydrophilic MWCNT layer deposited on a CuFe2O4-immobilized ceramic membrane to construct CCuFeCM. A pristine ceramic membrane (CM) and a CuFe2O4-immobilized membrane (CuFeCM) served as controls. Our results demonstrated that CCuFeCM presents the most alleviated fouling potential (∼18% of flux decline) and TOC removal (91%) when treating synthetic textile wastewater containing a mineral oil-in-water emulsion with RhB. Besides that, CCuFeCM achieves the highest PMS-based RhB degradation capability (100%) and initial reaction rate (0.684 min–1). Quenching experiments and EPR analyses show that SO4–•, •OH, and 1O2 are responsible for the CCuFeCM/PMS oxidation system, and 1O2 is the dominant reactive species. The synergistic effect of oil separation and catalytic decomposition is mainly ascribed to the ordered arrangement of selective separation in advance to avoid interference with subsequent AOPs, which allows for micropollutants that are transmitted into internal membrane channels for confined catalytic oxidation. Furthermore, replication filtration tests indicate that CCuFeCM shows durable stable degradation and antifouling performance after simple cleaning. The specific functionality of oil isolation, catalyst anchor, and mass transfer effect reaction compartmentation provides a novel strategy for efficient gradient removal of multiple pollutants in water, which highlights promising application potential under realistic conditions.
研究领域:
环境工程
·
废水处理
·
催化
·
膜技术
·
高级氧化过程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2023
·
IF 22.1
Jiaxin Li,Huiyu Yi,Yang Xiao,Chenge Liang,Yi Shen,Yungui Li,Qile Fang
Membrane catalysis is a frontier technology for effectively removing organic containments, and burgeoning membranes assembled from two-dimensional (2D) materials have significantly flourished in peroxymonosulfate (PMS)-based catalytic membrane processes. Here, a bottom-up strategy based on restricting CoFe Prussian blue analog (PBA) crystal growth in one direction is used to fabricate large-scale 2D blade-shaped PBA sheets, whose radial size and thickness can be adjusted by the precursor ion ratio (Co II /Fe II ). The stripe CoFe PBA sheets can directly serve as building blocks and are simply assembled into a free-standing 2D membrane by interweaving assembly. The assembled CoFe PBA catalytic membrane possesses excellent wetting properties, guaranteeing an unimpeded mass transfer process, which leads to a superior instantaneous catalytic performance for the antibiotic norfloxacin during the continuous and flow-through membrane catalytic process. SO 4 •− and 1 O 2 are demonstrated to be the main active species, which synergistically contribute to the PMS-driven organic degradation.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Sciences
·
2022
·
IF 6.796
Zhexin Zhu,Wenjie Qian,Zhiguo Shang,Xiaoji Ma,Zhendong Wang,Wangyang Lu,Wenxing Chen
The monoaminotrinitro iron phthalocyanine (FeMATNPc) is used to connect with isonicotinic acid (INA) for amide bonding and axial coordination to synthetic a unique catalyst FeMATNPc-INA, which is loaded in polyacrylonitrile (PAN) nanofibers by electrospinning. The introduction of INA destroys the π-π conjugated stack structure in phthalocyanine molecules and exposes more active sites. The FeMATNPc-INA structure is characterized by X-ray photoelectron spectroscopy and UV-visible absorption spectrum , and the FeMATNPc-INA/PAN structure is characterized by Fourier transform infrared spectroscopy and X-ray diffraction. The FeMATNPc-INA/PAN can effectively activate peroxymonosulfate (PMS) to eliminate carbamazepine (CBZ) within 40 minutes (PMS 1.5 mmol/L) in the dark. The effects of catalyst dosage, PMS concentration, pH and inorganic anion on the degradation of CBZ are investigated. It has been confirmed by electron paramagnetic resonance, gas chromatography–mass spectroscopy and free radical capture experiments that the catalytic system is degraded by • OH, SO 4 •− and Fe (IV) = O are the major active species, the singlet oxygen ( 1 O 2 ) is the secondary active species. The degradation process of CBZ is analyzed by ultra-high performance liquid chromatography-mass spectrometry and the aromatic compounds have been degraded to small molecular acids.
研究领域:
环境科学
·
化学工程
·
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Xiaxi Zhang,Fen Wei,Sicen Wang
4-nitrophenol (4-NP) and 2,4-dichlorophenol (2,4-DCP) contaminated wastewater have attracted attention for their genotoxic and carcinogenic hazards. The magnetic MIL-101/CFO was constructed by synergistically integrating porous/hydrophilic/π-conjugated MIL-101(Cr) and CoFe 2 O 4 . The nanocomposites markedly accelerated the catalytic reaction activity. The BET characterizations reveal the nanocomposites had a larger specific surface area and pore volume in comparison to the individual CoFe 2 O 4 . The composite was employed to evaluate the adsorption and peroxymonosulfate (PMS)-activated ability of 4-NP and 2,4-DCP elimination. The adsorption equilibrium could be achieved within 60 min, following the pseudo-second-order kinetic model and the Langmuir isotherm model. The nanocomposites (0.2 g·L −1 ) achieved exceeding 96 % decomposition efficiencies toward 4-NP and 2,4-DCP (0.1 g·L −1 ) after 15 min by PMS (5.29 mM) activation. Notably, the reaction system displayed effective catalytic performance across pH 5 − 11 and resistance to the existence of saline ions and humic acid. According to the free radical quenching experiments and electron paramagnetic resonance, the non-radical route dominant by 1 O 2 and few HO • and SO 4 •− were affirmed to participate the reaction. The recyclable MIL-101/CFO/PMS system approached high adsorption and catalysis ability for phenolics remediation in the environmental application.
研究领域:
环境科学
·
化学工程
·
材料科学
·
水处理
✓ 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）