SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Jiaojie He,Qingwang Cai,Ziyi Kang,Jingxin Zhang,Huan Tang,Tinglin Huang
Research on inorganic metal coagulants has largely focused on the Al, Fe, Ti and Zr-based salts, leaving insufficient studies on the metal Ce. This study first attempted to conduct an in-depth investigation into the coagulation effect of Ce-based reagents with different valence states. The CCl was a pure Ce(III)-based salt, while Ce(IV)/Ce(III) in CAN equaled 2.7/1. The results demonstrated that CAN possessed far superior capability of turbidity removal compared with CCl, which was on par with polyaluminum chloride (PAC). And its ability to remove organic matter even surpassed that of PAC. Furthermore, CAN exhibited more remarkable and stable performance across a broad pH range. Mechanism studies confirmed that the Ce(III) had the strongest organic ligand complexing ability but insufficient hydrolysis ability, leading the complex re-stabilized in solution. Whereas, the merits of Ce(IV) was based on the following distinctive properties: (1) the high positive charge, with zeta potential even close to that of PAC under acidic condition, (2) the readily formed hydrolysis products owning film-like structure to enhance sweep flocculation, (3) the high coordination number to offer abundant reaction sites to balance the three effects, electric neutralization, complexation, and sweeping, to fully exploit their respective advantages. Thus, the above three effects were combined to achieve the stable coagulation efficiency in CAN containing both Ce(IV) and Ce(III), which might be insufficient or competitive in PAC or CCl. The clarification of the coagulation mechanisms is conducive to better developing Ce-based coagulants and may offer valuable insights into finding more suitable metal-based reagents.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-14
·
IF 14.7
Ye Runping,Ma Lixuan,Mao Jianing,Wang Xinyao,Hong Xiaoling,Gallo Alessandro,Ma Yanfu,Luo Wenhao,Wang Baojun,Zhang Riguang,Duyar Melis Seher,Jiang Zheng,Liu Jian
CO 2 hydrogenation to chemicals and fuels is a significant approach for achieving carbon neutrality. It is essential to rationally design the chemical structure and catalytic active sites towards the development of efficient catalysts. Here we show a Ce-CuZn catalyst with enriched Cu/Zn-O V -Ce active sites fabricated through the atomic-level substitution of Cu and Zn into Ce-MOF precursor. The Ce-CuZn catalyst exhibits a high methanol selectivity of 71.1% and a space-time yield of methanol up to 400.3 g·kg cat −1 ·h −1 with excellent stability for 170 h at 260 °C, comparable to that of the state-of-the-art CuZnAl catalysts. Controlled experiments and DFT calculations confirm that the incorporation of Cu and Zn into CeO 2 with abundant oxygen vacancies can facilitate H 2 dissociation energetically and thus improve CO 2 hydrogenation over the Ce-CuZn catalyst via formate intermediates. This work offers an atomic-level design strategy for constructing efficient multi-metal catalysts for methanol synthesis through precise control of active sites.
研究领域:
催化
·
化学工程
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CEMENT AND CONCRETE RESEARCH
·
2024
·
IF 10.9
Haosen Ma,Yanjie Tang,Wei Chen,Qiu Li
The immobilisation mechanism of Pu(IV) by Portland cement-based material is not well understood. This study aims to reveal the immobilisation mechanism and occurrence status of Ce(IV) (chemical analogue of Pu(IV)) in Portland cement paste. The addition of Ce(NO 3 ) 4 first slightly retarded then accelerated the early-age hydration of Portland cement , thereby resulting in an increase of compressive strength by 29 %. The main contributor to immobilisation of Ce is Portland cement rather than zeolite . The hydration products were not altered by Ce(NO 3 ) 4 addition, whereas the hydration degree and mean chain length of C-(Al/Ce)-S-H increased. Over 99.99 % of Ce was immobilised by synthesised C-S-H. A analysis of the synthesised C-S-H confirmed the formation of C-Ce-S-H, where Ce tetrahedra took the bridging site of silicate chain of C-Ce-S-H. Nano-crystalline CeO 2 grains were identified, which intermixed with C-Ce-S-H. Approximately 90 % of Ce were immobilised by C-Ce-S-H, and the rest exist as nano-crystalline CeO 2 grains.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Xuwen Chen,Peixin Wang,Fei Peng,Zhou Zhou,Michael Gatheru Waigi,Wanting Ling
Substituted polycyclic aromatic hydrocarbons (SPAHs) are being intensively investigated, considering their high toxicity. Additionally, the mechanism of the effect of substituents on the removal of SPAHs and the activation of Ce(III) ions on peroxymonosulfate (PMS) have not been explored. Here we evaluated the removal efficiency of SPAHs in the oxidation system constructed by Ce(Ⅲ) ions and PMS, with emphasized the effect of substituents on SPAHs degradation. Ce(Ⅲ) has high catalytic performance for PMS, and the degradation percentage of all pollutants was higher than 92%. The significantly negative correlation between the reaction rate constants of SPAHs and the highest occupied molecular orbital-the lowest unoccupied molecular orbital gap, confirms that substituents lead to the differences in the degradation of SPAHs. The generation of reactive oxygen species (SO 4 •− , • OH, and 1 O 2 ) is based on the electron transfer between Ce(Ⅲ) and PMS, and the contribution of ROS to substituted naphthalene varies due to the role of substituents. The Ce(Ⅳ)/Ce(Ⅲ) cycle accelerates the activation of PMS. Based on the transformation products and condensed Fukui function, the possible degradation pathways are inferred. In addition, inorganic anions and organic matter have little effect on the Ce(Ⅲ)/PMS system, which is a prerequisite for applying this system to real-world waste-water for SPAHs removal. This work demonstrates a new model of the degradation mechanism of SPAHs in the Ce(Ⅲ)/PMS system.
研究领域:
环境化学
·
水处理
·
污染物降解
·
催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ChemSusChem
·
2021
·Vol. 14
·期 7
·1747-1755
·
IF 8.928
Xiaozhou Cao,Song Wang,Xiangxin Xue
Graphical Redox flow battery : A Zn−Ce redox flow battery based on choline chloride ethylene glycol deep eutectic solvent was studied. The open-circuit voltage of the battery reaches 2.2 V, and the coulombic efficiency of the battery is stable at about 84 %, which may provide theoretical support for the development of large-scale energy storage system. Compared with conventional aqueous and ionic liquid electrolytes, deep eutectic solvent (DES) are considered as electrolyte for redox flow batteries because they have a wider electrochemical window and relatively low price. In this study, Ce IV /Ce III and Zn II /Zn redox couples are used as the positive and negative active materials, respectively, in an electrolyte consisting of choline chloride ethylene glycol (ethaline). The structure of Ce III in the positive electrolyte is inferred through spectrum detection. Ce IV /Ce III and Zn II /Zn redox couples show a stable potential difference of 2.2 V (vs. Ag) through cyclic voltammetry. The charge and discharge performance of battery was tested at different current densities. In addition, battery performance was evaluated at different temperatures and concentrations of cerium in the electrolyte. Consequently, at a current density of 0.5 mA cm −2 at room temperature and using 1.0 m Ce III , the battery performance reaches the best coulombic efficiency of 84 %.
研究领域:
电化学
·
储能
·
材料科学
·
电池技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2021
·
IF 5.706
Wei Sun,Shijie Shao,Jun Pan,Yangyang Wang,Hangqi Xia,Xiaohui Gao,Hao Zhang,Qiguang Dai,Li Wang,Xingyi Wang
Ce-Ti-Zr mixed oxide catalysts prepared by sol-gel method were used in catalytic combustion of CH 2 Cl 2 . The characterization reveals that the incorporation of Ce and Zr into TiO 2 anatase or Ti and Zr into CeO 2 fluorite promotes hydroxyl groups, Lewis acidity and surface oxygen through the formation of Ti-O-Zr, Ti-O-Ce and Ce-O-Zr species. Ce-Ti-Zr catalysts show high activity for CH 2 Cl 2 oxidation with the rate of 5.66 × 10 −3 –6.45 × 10 −3 μmol s −1 m −2 at 250 °C and high stability for 50 h. The substitution of surface oxygen for Cl maintains the availability of Ti-OH and thus promotes Cl removal as HCl, which is verified by a great increase in the stable activity of physically closely contacted mixture of separated CeO 2 and TiO 2 or Ti 9 Zr 1 particles. In situ FT-IR shows that CH 2 Cl 2 interacts with Ti-OH to form -O-CH 2 -O-, which is quickly rearranged into formate. Finally, formate is oxidized with surface oxygen into CO or CO 2 .
研究领域:
催化
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2022
·
IF 8.047
Jiancai Hou,Jiangliang Hu,Liping Chang,Jiancheng Wang,Zequan Zeng,Dongxia Wu,Xinmin Cui,Weiren Bao,Junxuan Yao
Cu-Ce mixed oxides with different Cu contents were synthesized through a sol–gel method, after which their effect on benzene combustion catalysis was evaluated. CeCu0.50 calcined at 300 °C (CeCu0.50–300) exhibited a high areal rate [2.0 × 10 −6 mol/(m 2 h)] and turnover frequency (0.16 s −1 ) at 170 °C, thus demonstrating the strong synergistic effect between CuO and CeO 2 . The catalyst durability and influence of H 2 O(g) on catalytic activity were also investigated. Correlation analyses between the catalytic activities and the amount of copper species, indicated that CuO x clusters and the Cu-[O x ]-Ce structure were the main active sites and bridge for oxygen transfer, respectively. Furthermore, benzene did not adsorb onto the copper species. The effect of temperatures on surface oxygen vacancies and oxygenated intermediates were also evaluated. Taken together, our findings provided key insights into the synergistic effects of different copper species on benzene combustion.
研究领域:
催化化学
·
环境科学
✓ 已验证
DOI
高影响因子
Molecular Catalysis
·
2022
·
IF 5.089
Chengcheng Yi,Jia Fang,Ping Pu,Yi Yang,Zong Chen,Zinong Zuo,Zhiqiang Han
A series of K-Ce catalysts with different K/(K+Ce) molar ratios are successfully prepared by hydrothermal method, to optimize catalyst diesel particlate filter (CDPF) regeneration efficiency of soot elimination. The K-Ce catalyst is an excellent promoter for soot combustion by thermogravimetric analysis (TGA), and the KC-0.2 catalyst has the best catalytic activity because proper K ions lead to more oxygen vacancies and improve contact efficiency with soot. This result corresponds well to characterization analysis, such as XRD, SEM and XPS. In a 10%O 2 /90%N 2 atmosphere, the KC-0.2 has the highest average mass loss rate ( W mean ), maximum mass loss rate ( W max ) and combustion stability index ( R w ). The weight ratios of the soot/KC-0.2 mixture are less than 1:10, making catalytic oxidation easier for the soot. Thermal aging in static air at 600 °C is used to investigate the catalytic stability of KC-0.2, and the TGA results show that KC-0.2 has good stability at temperatures lower than 600 °C. Compare to KC-0.2, the KC-0.2 based mixed catalyst with ZrO 2 participation is further prepared by mechanical method and has better catalytic activity because the presence of Zr enhances redox surface sites of catalyst. This facilitates the exploration of novel catalysts through combinatorial catalysis.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Environmental Progress & Sustainable Energy
·
2016
·Vol. 36
·期 2
·494-504
·
IF 1.631
Zhengjiang Liu,Lei Xing,Huiyan Ma,Lin Cheng,Juming Liu,Jucai Yang,Qiancheng Zhang
Sulfated Ce-doped TiO 2 photocatalysts, with improved visible light photocatalytic activity, are prepared by sol-gel method and via impregnation with diluted sulfuric acid. The synthesized samples are characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet–visible diffuse reflectance spectra (UV–Vis DRS), Fourier transform infrared (FTIR) spectroscopy, temperature-programmed desorption of ammonia (NH 3 -TPD) and X-ray photoelectron spectroscopy (XPS). To investigate the effect of Ce doping as well as acid sites on the photoactivity of the synthesized photocatalyst, photocatalytic degradation of Rhodamine B in an aqueous solution is used as a probe reaction to evaluate the photocatalytic activity of the as-prepared samples under visible light irradiation. It reveals that Ce doping can improve the photocatalytic response of TiO 2 to visible light and the presence of Ce 4+ /Ce 3+ redox process facilitates the separation of photo-generated electrons and holes. In addition, the impregnation can create Lewis acid sites on the obtained catalyst surface. Lewis acid sites on the catalyst surface could increase the amount of adsorbed oxygen (O ad ) and consequently improve the transform efficiency of Ce 3+ to Ce 4+ . Thereafter an increase in the phtocatalytic activity of sulfated Ce-doped TiO 2 is achieved. The possible mechanism of RhB degradation by sulfated Ce-doped TiO 2 photocatalyst is preliminarily discussed. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 494–504, 2017
研究领域:
环境工程
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2023
·
IF 8.8
Yuxi Liao,Peng Liu,Jun Zhang,Can Wang,Longwen Chen,Dengfeng Yan,Quanming Ren,Xiaoliang Liang,Mingli Fu,Suib Steven L.,Daiqi Ye
Increasing the contact efficiency and improving the intrinsic activity are two effective strategies to obtain efficient catalysts for soot combustion. Herein, the electrospinning method is used to synthesize fiber-like Ce–Mn oxide with a strong synergistic effect. The slow combustion of PVP in precursors and highly soluble manganese acetate in spinning solution facilitates the formation of fibrous Ce–Mn oxides. The fluid simulation clearly indicates that the slender and uniform fibers provide more interwoven macropores to capture soot particles than the cubes and spheres do. Accordingly, electrospun Ce–Mn oxide exhibits better catalytic activity than reference catalysts, including Ce–Mn oxides by co-precipitation and sol-gel methods. The characterizations suggest that Mn 3+ substitution into fluorite-type CeO 2 enhances the reducibility through the acceleration of Mn–Ce electron transfer , improves the lattice oxygen mobility by weakening the Ce–O bonds, and induces oxygen vacancies for the activation of O 2 . The theoretical calculation reveals that the release of lattice oxygen becomes easy because of a low formation energy of oxygen vacancy, while the high reduction potential is beneficial for the activation of O 2 on Ce 3+ -Ov (oxygen vacancies). Due to above Ce–Mn synergy, the CeMnO x -ES shows more active oxygen species and higher oxygen storage capacity than CeO 2 -ES and MnO x -ES. The theoretical calculation and experimental results suggest that the adsorbed O 2 is more active than lattice oxygen and the catalytic oxidation mainly follows the Langmuir-Hinshelwood mechanism. This study indicates that electrospinning is a novel method to obtain efficient Ce–Mn oxide.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
TALANTA
·
2023
·
IF 6.1
Yilin Wang,Jia Chen,Chenxi Wang,Li Zhang,Yaqi Yang,Chao Chen,Yixi Xie,Pengcheng Zhao,Junjie Fei
As a common antioxidant and nutritional fortifier in food chemistry, rutin has positive therapeutic effects against novel coronaviruses. Here, Ce-doped poly(3,4-ethylenedioxythiophene) (Ce-PEDOT) nanocomposites derived through cerium-based metal-organic framework (Ce-MOF) as a sacrificial template have been synthesized and successfully applied to electrochemical sensors. Due to the outstanding electrical conductivity of PEDOT and the high catalytic activity of Ce, the nanocomposites were used for the detection of rutin. The Ce-PEDOT/GCE sensor detects rutin over a linear range of 0.02–9 μM with the limit of detection of 14.7 nM (S/N = 3). Satisfactory results were obtained in the determination of rutin in natural food samples (buckwheat tea and orange). Moreover, the redox mechanism and electrochemical reaction sites of rutin were investigated by the CV curves of scan rate and density functional theory. This work is the first to demonstrate the combined PEDOT and Ce-MOF-derived materials as an electrochemical sensor to detect rutin, thus opening a new window for the application of the material in detection.
研究领域:
分析化学
·
电化学
·
材料科学
·
食品化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2018
·
IF 6.434
Yangchun Leng,Qintang Li,Qiang Tian,Xiaoyuan Chen,László Almásy,Yuliang Liu,Guangai Sun,Xianguo Tuo,Minhao Yan,Mark J. Henderson
The ability of bentonite and montmorillonite pillared by Al-oxide and mixed (Ln-Al)-oxides (Ln = La, Ce) to remove 239 plutonium solution species from water is comparatively investigated at pH 7 and pH 4. Small-angle scattering and neutron contrast variation with H 2 O/D 2 O mixtures is used to verify the ingress of water in the calcined products after hydrophilicity was introduced by an NH 3 -H 2 O vapor treatment. The size and shape of the (La/Ce)-Al oxo-hydroxy pillaring cations (2 nm spheres) is determined by small-angle x-ray scattering from the pillaring solutions. Not all of the oxide pillars improved Pu uptake compared with sodium montmorillonite. At neutral and acidic pH only (Ce-Al)-oxide pillared clays showed the ability to remove Pu over the concentration range studied (1.35 × 10 −8 –8 × 10 −8 mol dm −3 ) with distribution coefficient ( K D ) values >10 4 . XPS analysis of the (Ce-Al)-oxide pillared clays indicates the presence of Ce 4+ as cerium dioxide. The progressive improvement in sorption performance in the order of pillar type Al 2 O 3 < La 2 O 3 -Al 2 O 3 << CeO 2 -Al 2 O 3 reflects the increasing access of Pu solution species to the clay mineral layers by changes to the basal spacing and specific surface area, and also to the higher stability of the (Ce-Al)-oxide pillars.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）