SURFACE AND INTERFACE ANALYSIS
·
2025
·
IF 1.8
Huiling Jia,Sen Li,Menghao Liang,Jinxiu Wu,Xin Tan
The cationic surfactant hexadecyltrimethylammonium bromide (CTAB), Ce (NO 3 ) 3 ·6H 2 O, and ammonium nitrate/ethanol mixed solution were used as the mesoporous guiding template, the cerium source, and the selective solvent. PS@ m CeO 2 abrasives were synthesized using polystyrene (PS) as the core and mesoporous ceria ( m CeO 2 ) as the shell. The properties of PS@ m CeO 2 abrasives were examined by field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR), small-angle X-ray diffraction (XRD), HRTEM, X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption–desorption. The results showed that m CeO 2 was completely coated on the PS, with the PS core size of 240 nm and the m CeO 2 shell thickness of 15–20 nm. The content of O vacancies and Ce 3+ increased in the m CeO 2 shell. Irregular mesopores were formed in the shell. Young's modulus ( E ) and polishing property of CeO 2 abrasive, PS@CeO 2 composites, and PS@ m CeO 2 composites were measured by atomic force microscopy. The E of core@shell-structured composites significantly decreased. The PS@ m CeO 2 composites reduced mechanical damage and scratches and improved the material removal rate to 172 nm/min.
研究领域:
材料科学
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纳米技术
·
表面科学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2025
·
IF 5.4
Jian Gao,Xinrui Dai,Zhenhua Gu,Guixian Deng,Jiangyong Yuan,Kongzhai Li
Catalysts loaded with metal oxides of M (M = Mn, Co, Ce) were synthesized by deposition precipitation method using cold rolled sludge (iron oxide as the main component) as a raw material for the selective catalytic reduction of NO x by ammonia (NH 3 -SCR). Among the various formulations, the co-supported catalyst containing 5 % Mn and 5 % Co on CRS-400 exhibited exceptional SCR performance, achieving over 90 % conversion of NO x from 80 °C to 200 °C. The addition of 5 % Mn and 5 % Co as active components resulted in an increase in the specific surface area for catalytic performance and an enhancement of the redox capacity, leading to a significant improvement in catalyst activity. The catalyst’s efficient denitration performance was attributed to the synergistic interaction between Mn, Co, and Fe oxides, resulting in a catalyst with a higher proportion of adsorbed oxygen, as well as an elevated composition of Mn 4+ and Fe 2+ species. The catalyst demonstrated excellent SCR activity at low-temperatures, indicating its potential for downstream applications in soot treatment equipment. This would achieve the dual benefits of purifying the atmosphere and disposing of solid waste.
研究领域:
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
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2021
·
IF 9.028
Fengping Zhou,Ye Xiao,Meina Guo,Yetao Tang,Weihua Zhang,Rongliang Qiu
The increasing demand for rare earth elements (REEs) motivates the development of novel strategies for cost-effective REE recovery from secondary sources, especially rare earth tailings. The biggest challenges in recovering REEs from ion-adsorption rare earth tailings are incomplete extraction of cerium (Ce) and the coleaching of iron (Fe) and manganese (Mn). Here, a synergistic process between reduction and stabilization was proposed by innovatively using elemental sulfur (S) as reductant for converting insoluble CeO2 into soluble Ce2(SO4)3 and transforming Fe and Mn oxides into inert FeFe2O4 and MnFe2O4 spinel minerals. After the calcination at 400 °C, 97.0% of Ce can be dissolved using a diluted sulfuric acid, along with only 3.67% of Fe and 23.3% of Mn leached out. Thermodynamic analysis reveals that CeO2 was indirectly reduced by the intermediates MnSO4 and FeS in the system. Density functional theory calculations indicated that Fe(II) and Mn(II) shared similar outer electron arrangements and coordination environments, favoring Mn(II) over Ce(III) as a replacement for Fe(II) in the FeO6 octahedral structure of FeFe2O4. Further investigation on the leaching process suggested that 0.5 mol L–1 H2SO4 is sufficient for the recovery of REEs (97.0%). This research provides a promising strategy to selectively recover REEs from mining tailings or secondary sources via controlling the mineral phase transformation.
研究领域:
化学工程
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环境科学
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材料科学
✓ 已验证
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Jie Cheng,Shuo Huang,Yang Li,Tongqing Wang,Lile Xie,Xinchun Lu
Ce 3+ in CeO 2 , rather than Ce 4+ , is believed to provide assistance to the breaking up of Si O bond during chemical mechanical polishing (CMP) of silica. In the paper, lanthanide metals (La, Nd and Yb) doped CeO 2 nanoparticles were synthesized by modified incipient impregnation method in order to improve the content of Ce 3+ in CeO 2 as polishing. X-ray photoelectron spectroscopy (XPS) experiments and density function theory (DFT) calculation demonstrate this approach could achieve surface doping of CeO 2 nanoparticles, and facilitates the formation of oxygen vacancy and Ce 3+ content. CMP experiments show that the polishing rate and the surface quality of silica wafer are obviously improved by using the doped CeO 2 as abrasive particles. Especially for Nd/CeO 2 , content of Ce 3+ increases from 0.146 to 0.235, the polishing rate of silica is accelerated by 29.6% in alkaline slurries, and a better surface quality (Sa = 9.6 Å) is obtained.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 43
·19974-19982
·
IF 3.3
Hao Fan,Qin Peng,Zhenxing Shen,Xuefeng He,Yiming Yang
Nitric oxide (NO), a major atmospheric pollutant and a precursor to haze, can be removed using the denitration catalyst. Mn and Ni are commonly used as denitration catalyst additives owing to their adsorption abilities for NO and ammonia (NH3). In this study, we synthesized Mn- and Ni-loaded Pt-modified sulfated cerium oxide (PtSCe) catalysts using an impregnation method and explored the effects of these elements. The results revealed that the two elements had contrasting effects on the denitration activity of the catalysts. Mn improved the water vapor and sulfur resistance of the PtSCe sample by increasing the concentration of weak acid sites, enhancing the redox ability, and increasing the content of surface-adsorbed oxygen. The elevation in oxygen vacancies, stimulated by the presence of Ce3+ and Mn3+, swiftly replenished the reactive oxygen species, thereby sustaining the high denitration efficiency of the MnPt/SCe sample. Active sites on the catalyst surface included NH3 adsorbed on Lewis acid sites, NH4+, and –NH2, along with bridging, monodentate, and bidentate nitrate groups. Regarding the catalyst reaction mechanism, we determined that the selective catalyst reduction of NH3-SCR over MnPt/SCe followed both the Eley–Rideal and Langmuir–Hinshelwood mechanisms. These findings offer crucial insights into the intricate relationship between metals, sulfates, and carrier molecules, thus providing implications for future catalyst design.
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
Catalysts
·
2023
·Vol. 13
·期 4
·781
·
IF 3.9
He Sun,Juping Zhang,Kongzhai Li,Hua Wang,Xing Zhu
HighlightsWhat are the main findings?A styrene yield of 91.4% was found for 10% k/CeO2at 500 °C and CO2-O2mixed atmosphere. The excellent catalytic performance of 10% k/CeO2is attributed to the alkali metal oxide modified cerium oxide and carbon dioxide induced oxygen vacancies to promote the dehydrogenation of ethylbenzene.What is the implication of the main finding?The proposed ODH strategy by using oxygen vacancies enriched catalysts offers an important insight into the efficient dehydrogenation of ethylbenzene at mild conditions.AbstractOxidative dehydrogenation (ODH) is an alternative for styrene (ST) production compared to the direct dehydrogenation process. However, ODH with O2or CO2suffers from either over-oxidation or endothermic property/low ethylbenzene conversion. Herein, we proposed an ODH process with a CO2-O2mixture atmosphere for the efficient conversion of ethylbenzene (EB) into styrene. A thermoneutral ODH is possible by the rationalizing of CO2/O2molar ratios from 0.65 to 0.66 in the temperature range of 300 to 650 °C. K modification is favorable for ethylbenzene dehydrogenation, and 10%K/CeO2achieved the highest ethylbenzene dehydrogenation activity due to the enhanced oxygen mobility and CO2adsorbability. The catalyst achieved 90.8% ethylbenzene conversion and 97.5% styrene selectivity under optimized conditions of CO2-4O2oxidation atmosphere, a temperature of 500 °C, and a space velocity of 5.0 h−1. It exhibited excellent catalytic and structural stability during a 50 h long-term test. CO2induces oxygen vacancies in ceria and promotes oxygen exchange between gaseous oxygen and ceria. The ethylbenzene dehydrogenation in CO2-O2follows a Mars-van Krevelen (MvK) reaction mechanism via Ce3+/Ce4+redox pairs. The proposed ODH strategy by using oxygen vacancies enriched catalysts offers an important insight into the efficient dehydrogenation of ethylbenzene at mild conditions.Keywords:ethylbenzene;oxidative dehydrogenation;ceria;CO2
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2016
·
IF 7.354
Shuang Liu,Xiaodong Wu,Wei Liu,Wenming Chen,Rui Ran,Min Li,Duan Weng
Three model ceria catalysts, which are monocrystalline CeO 2 nanocubes, polycrystalline CeO 2 nanoparticles, and polycrystalline CeO 2 spindles, were synthesized and analyzed with isothermal soot oxidation, H 2 -TPR, and Raman spectroscopy. The results suggest that the initial activity of the catalyst is determined by the number of catalyst–soot contact points rather than the catalyst surface area, while the catalyst stability is closely related to the concentration of surface oxygen vacancies . Excessive surface oxygen vacancies may inhibit the regeneration of highly active O 2 − and lead to catalyst deactivation during reaction. After impregnation with Ag, O − can be readily regenerated and transformed to O 2 − , resulting in a 10-fold increase in soot oxidation activity over Ag/CeO 2 . Among these catalysts, Ag supported on nanocubic CeO 2 exhibits good availability of O 2 − and therefore high catalytic activity and stability, and is thus considered a promising catalyst for application in gasoline particulate filters.
研究领域:
催化化学
·
环境科学
·
材料化学
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能源工程
·
大气污染控制
✓ 已验证
DOI
高影响因子
SOLAR ENERGY
·
2019
·
IF 4.674
Binxia Yuan,Xiaobo Liu,Xiaodong Cai,Xinyi Fang,Jianfeng Liu,Maoliang Wu,Qunzhi Zhu
In the paper, the zinc and cerium or both doped cuprous oxide (Cu 2 O) crystals were successfully synthesized under low temperature by a simple hydrothermal process. The surface morphologies, structure properties, and optical properties of Cu 2 O crystals were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and UV-visible absorption spectroscopy. The morphology of pure Cu 2 O crystals, Zn:Cu 2 O crystals, Ce:Cu 2 O crystals and Zn/Ce:Cu 2 O crystals evolved to irregularly cubic structure, exfoliated octahedron, were regular octahedron, and like-spherical aggregate, respectively. The doping of Cu 2 O crystals not only affected the surface morphologies but also significantly influenced the optoelectronic properties. Compared with undoped cuprous oxide, the doped samples had larger optical band gaps. Finally, the aggregation and diffusion were the most important factors for the morphology evolution of Cu 2 O crystal.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2017
·
IF 2.594
Zhaopeng Liu,Yan Xu,Zhenhua Li,Baowei Wang,Weihan Wang,Xinbin Ma,Renjie Liu
In this paper, Ce 0.2 Zr 0.8 O 2 composite supports were prepared by different Ce-addition methods including impregnation of cerium (CeZr-imp), impregnation of citric acid and cerium (CeZr-CA) simultaneously and deposition precipitation method (CeZr-DP), respectively. The as-prepared supports were applied to prepare 10 wt% MoO 3 /Ce 0.2 Zr 0.8 O 2 catalysts for sulfur-resistant methanation . The N 2 adsorption/desorption, X-ray diffraction (XRD), Raman spectroscopy (RS), X-ray photoelectron (XPS), temperature-programmed reduction by hydrogen (H 2 -TPR) were undertaken to get textural properties, morphological information and structures of the catalysts. The results showed that MoO 3 was highly dispersed on the surface of these three supports and Ce was mostly of coexisted in Ce 4+ /Ce 3+ redox pairs. Compared with Mo/CeZr-imp, the CO conversion increased by 10% and 15% for Mo/CeZr-CA and Mo/CeZr-DP, respectively. This was mainly attributed to the larger specific surface area, Ce 3+ concentration and content of active MoS 2 on the surface of catalysts.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2024
·
IF 1.5
Gado Mohamed A.
(Pyridine-2,5-diylbis(azaneylylidene)) bis-(methaneylylidene)) bis(benzene-5,1,3-triyl) tetrakis (hydrogen phosphonate) (PZMB) was successfully synthesized for Th(IV) and Ce(IV) adsorption, the adsorption parameters evaluated and found to be pH 3.5, time 60 min, dose 0.15 g. Adsorption kinetics, isotherm, and thermodynamics studies. Adsorption kinetics studies show that adsorbent follow pseudo-second-order model while isotherm studies conclude that adsorption processes fitted Langmuir and D-R isotherm model. The maximum adsorption capacity of BZMB of Th(IV) and Ce(IV) are 366.4 and 244.53 mg/g respectively, Thermodynamic studies indicate both adsorption processes exhibited by the PZMB were endothermic, spontaneous and sorption occurs in a random manner.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Superconductivity and Novel Magnetism
·
2024
·
IF 1.6
Pi Siwen,Li Jie,Zhang Yingde,Zhou Weina,Shan Shuo,Zhao Xuan
Ce-substituted M-type Sr 1– x Ce x Fe 12 O 19 ( x = 0.00–0.08) ferrites were successfully synthesized via the ball milling method, and the sintering temperature at 1200 °C for 2 h. The synthesized materials were characterized by X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), and vibrating sample magnetometry (VSM). The elemental makeup of the samples was characterized by energy-dispersive spectrometry (EDS). The XRD results showed the crystal structure and purity of the samples. The FTIR spectroscopy indicated tetrahedral and octahedral tensile vibrations of M-type strontium ferrite at two characteristic peak bands of 554 and 454 cm −1 . The FESEM showed that Ce doping resulted in fine grains. The EDS indicated that Ce content increased with decreasing Sr concentration but that the concentrations of other elements remained basically unchanged. The mass ratio of Sr:Fe is calculated from EDS results and the measured Sr:Fe mass ratio is quite close to the mass ratio calculated from the reactants used to synthesize each sample. The VSM showed that at a Ce doping of x = 0.02, the coercivity of the samples reached the maximum, and the coercivity values and the saturation magnetization were 3878.25 Oe and 73.625 emu/g, respectively. And such high thermal stability further determines that Ce-substituted strontium ferrites have infinite potential in application fields (T = 450.2 °C).
研究领域:
材料科学
·
磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2024
·Vol. 171
·期 12
·122503
·
IF 3.1
Yanhong Jia,Hong Zhang,Ahmet Burak Çubuk,Biao Wu,Shaoqiang Guo
A mesh-type assembly and stirrer assembly were developed to improve the performance of liquid cadmium cathodes for the electrodeposition of U and Ce from LiCl-KCl molten salt at 773 K. The thermodynamic basis for electrodepositing U and Ce was established through the calculation of equilibrium potentials and cyclic voltammograms, while also examining the co-deposition of Li. Thereafter, U and Ce electrodeposition was performed by galvanostatic electrolysis, and the current efficiency was determined. It was found that both assemblies effectively hampered the growth of U dendrites and Ce-Cd dendritic alloys. However, the utilization of the mesh-type assembly resulted in a greater current efficiency for U, with the maximum deposited amount attaining 7.7 wt% U/Cd without causing U dendrites formation. In contrast, the current efficiency for Ce was enhanced after using the stirrer assembly due to an improved diffusion flux of Ce ions. Finally, cathode deposits were characterized by scanning electron microscopy, energy-dispersive spectroscopy, and X-ray diffraction, which revealed that disrupted fine U dendrites were randomly scattered in the Cd bulk, and that the CeCd11 dendritic alloys were also damaged, leading to an increased atomic ratio of Ce to Cd at the Cd bottom.
研究领域:
材料科学
·
电化学
✓ 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）