CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Xuan Wang,Zhenkuang Lei,Chunlin Zheng,Xueheng Zhuang,Qikui Man,Guoguo Tan
Semiconductor metal oxides are widely used in the field of wave absorption because of their easily tunable dielectric properties . Doping or modulating the morphology has been demonstrated to be an effective method to improve the microwave (MW) absorbing performance of semiconductor metal oxides. In this study, Ce-doped SnO 2 was prepared by a simple and effective coprecipitation method. Single-crystal SnO 2 nanorods were generated during the doping process and the size of the nanorods could be controlled by modifying the concentration of Ce. The presence of nanorods greatly enhances the MW absorbing performance: when the doping molar ratio is 3%, the minimum reflection loss of the absorber is −77.91 dB at a frequency of 13.79 GHz with a thickness of 1.6 mm and the maximum effective absorbing bandwidth is 4.47 GHz at a thickness of 1.5 mm. Excellent MW absorbing performance of Ce-doped SnO 2 is attributed to its excellent impedance matching and interfacial polarization.
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高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Zeyu Jiang,Shengying Zhao,Yuhao Yang,Minghui Tan,Guohui Yang,Yisheng Tan
As one of the most important green chemicals, dimethyl carbonate (DMC) has wide application prospects in electrochemistry, fuel additive, solvent and building block in organic synthesis. The effective utilization of CO 2 to synthesize DMC has been proved to be highly advantageous. In this study, a series of Ce-BTC MOF-derived nanorod CeO 2 catalysts for the direct synthesis of DMC from CO 2 and methanol were prepared via complexation reaction at room temperature and then thermal decomposition under different atmospheres. The calcination atmosphere had great influence on the structure and catalytic properties of obtained CeO 2 catalysts. The CeO 2 derived from calcination of Ce-BTC at 500 °C under H 2 atmosphere exhibited higher specific surface area, oxygen vacancy concentration and CO 2 adsorption capacity. And thus, its DMC yield was up to 6.332 mmol/g CeO2 within 4 h, much higher than that of commercial nano CeO 2 and other as-prepared catalysts in absence of dehydrating agents.
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高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2019
·Vol. 33
·期 3
·e4745
·
IF 3.259
Yibing Xie,Langlang Wang,Ping Ning,Xueqian Wang,Qi Wang,Yingjie Zhang,Mengyu Wang
A series of Ce modified catalysts were prepared using equivalent-volumetric ultrasonic impregnation method for AsH 3 removal. The performance of catalytic oxidation of AsH 3 under dynamic conditions was studied under different synthesis and reaction conditions. Through screening tests, the optimum catalyst was impregnated by 10 wt.% Ce (CH 3 COO) 3 precursor and subsequently calcinated at 550 °C. When the reaction temperature reached 170 °C, the Ce-HZSM-5 catalyst could maintain an oxidation efficiency of over 90% in 82 hrs. Furthermore, the chemical structure and properties of the catalyst and its catalytic oxidation mechanism with AsH 3 were analyzed using SEM-EDS, BET, XRD, XPS, H 2 -TPR and FT-IR. The results showed that Ce mainly existed on the catalyst surface in the forms of Ce 4+ and Ce 3+ . In the reaction process, the chemisorbed oxygen played a key role in the transformation between the two valence states. AsH 3 was firstly oxidized to elemental As with the participation of lattice oxygen. Then, the elemental As was partially blown into the rear part of the adsorption column along with the air flow and subsequently, de-sublimed on the column wall. Herein, the elemental As remained on the surface of Ce-HZSM-5 catalyst, which would further oxidize to As 2 O 3 . For the recovery of As, Ce-HZSM-5 proved to be a promising catalyst in AsH 3 removal. Highlights The CeO x modified HZSM-5 catalyst was used to catalytic oxidation of AsH 3 . The Ce-HZSM-5 catalyst could maintain over 90% oxidation efficiency in 82 hrs. AsH 3 was catalytic oxidized to elemental As and H 2 O on the catalyst surface and the As can be collected. The As adsorbed on the catalyst surface can be oxidized to As 2 O 3 but cannot be further oxidized to As 2 O 5 .
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高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2019
·Vol. 166
·期 13
·D638
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IF 3.12
Pengfei Xu,Xiaohong He,Junwei Mao,Yongming Tang
In this paper, Ti/SnO2-Sb/Ce-PbO2 anode is electrodeposited from MSA bath, and the effect of Ce3+ concentration in bath on the phase composition and morphology of lead dioxide electrode is elucidated. It is found that with the addition of 2 mM Ce3+ ion to the bath the Ce-PbO2 anode exhibits highest stability in 0.5 M H2SO4, and cerium exists as Ce (IV) in the PbO2 film. The electrocatalytic activity of lead dioxide anode for phenol removal is slightly enhanced by the inclusion of Ce. The significant improvement in electrocatalytic activity can be achieved by the addition of small amount of Bi3+ ion to the bath containing Ce3+ ion. In this study, electrocatalytic activities of various anodes follow the order: Ce,Bi-PbO2 > Ce-PbO2 > undoped PbO2 > Bi-PbO2.
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高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2018
·
IF 3.794
Lan Wang,Xiaoyan Shu,Facheng Yi,Dadong Shao,Kuibao Zhang,Haibin Zhang,Xirui Lu
A series of Nd and Ce co-doped Gd 2- x Nd x Zr 2- y Ce y O 7 (0.0 ≤ x , y ≤ 2.0) ceramics were rapidly fabricated through spark plasma sintering (SPS) within 3 min. The effects of Nd and Ce contents on the phase composition, lattice parameter , active modes, microtopography and microstructure have been investigated in detail. XRD studies reveal that the compositions corresponding to 0.0 ≤ y ≤ 1.0 show a single phase and beyond 1.0 exhibit multiphase. The lattice parameters increase with elevated Nd and Ce content. The grains are densely packed on each other with cube-like shape, and the elements are almost homogeneously distributed in the compound. This synthetic method provides a simple pathway for the preparation of highly densified single phase ceramic at 1600–1700 ℃ for 3 min under pressure of 80 MPa.
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高影响因子
Inorganic Chemistry Frontiers
·
2019
·Vol. 6
·期 7
·1799-1812
·
IF 5.934
Xiaosong Hu,Chaoyue Zhao,Qingxin Guan,Xin Hu,Wei Li,Jun Chen
The chemical transformation of CO2 not only mitigates CO2 released into the atmosphere but also produces fuels and chemicals with important additional value. The activation of stable CO2 molecules is the key difficulty for the efficient conversion of CO2. Herein, we designed a ternary catalyst containing Cu, ZnO, and CeOx and dispersed them in SBA-15 using incipient wetness impregnation. Interestingly, the catalytic performances were improved greatly when the related active components were dispersed inside and outside the pore channels of SBA-15 using the incipient wetness impregnation method. Methanol and CO were controllably produced on the interface of Cu and metal oxides (ZnO and CeOx) due to the synergistic effects between the three active components. The metal oxides play a more important role in CO2 conversion as well as the product selectivity compared to Cu. CeO2 is more efficient than ZnO in promoting the dispersion of Cu nanoparticles and methanol generation. The suitable pore channels of SBA-15 promote the mass transfer and heat transfer while the high specific surface area is favorable to the dispersion of active components, which will facilitate the production of methanol and CO. After continuous hydrogenation evaluation for 100 h, the catalytic performance of the catalyst was still very stable. This work provides a viable strategy to prepare a supported catalyst with highly dispersed active sites, and the catalyst exhibits an efficient catalytic effect on producing methanol and CO.
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高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Junli Liu,Wenxia Cheng,Kaitao Zhang,Hui Liu
Bacterial infections is a serious threat to our health. Thus, there is an urgent need to develop a new effective antibacterial agent. In this work, we developed a novel and environmentally friendly Ce–MoS 2 /WO 3 nanocomposite antimicrobial agent with excellent antimicrobial effect and the antimicrobial efficiency against E. coli reached to 97.8% under visible light irradiation. Electron paramagnetic resonance (EPR) spectra showed that the large amounts of superoxide anion radical (•O 2 − ) and hydroxyl radical (•OH) were generated by the nanocomposites under light excitation, which were the main active substances causing oxidative damage for bacteria. Simultaneously, the photothermal curve and peroxidase activity test of Ce–MoS 2 /WO 3 nanocomposites confirmed it has the excellent photothermal effect and enhanced enzyme-like activity, which further assisted in antibacterial effects. Ce doping enlarges the layer spacing of MoS 2 and forms lattice dislocations and distortions, effectively increasing the defect sites at the layer edges, and the coupling of Ce–MoS 2 and WO 3 to construct heterojunctions reduces the charge separation rate, which further improves the photocatalytic antibacterial performance and enzyme-like antibacterial activity of Ce–MoS 2 /WO 3 nanocomposites.
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高影响因子
Frontiers in Environmental Science
·
2022
·
IF 5.411
Wang Qinghong,Ji Yuanyuan,Hu Jingze,Ye Huangfan,Liu Ya,Wang Yuxian,Chen Chunmao,Li Zhuoyu
Cerium oxides loaded silica catalysts were synthesized by an impregnation method by simply mixing Ce precursor with silica spherule (Ce/SS) and ordered MCM-41 zeolites (Ce/MCM-41), followed by a mild calcination. Compared with pure SS and MCM-41, Ce modified Ce/SS and Ce/MCM-41 demonstrate much improved catalytic ozonation activities for mineralization of recalcitrant nitrobenzene (NB). At solution pH of 6, 86 and 97% TOC mineralization rates were achieved within 60 min for Ce/MCM-41 and Ce/SS, respectively. Characterization results suggest that Ce loading significantly increases the surface Lewis acidic sites, which would synergize with Ce3+/Ce4+ redox cycle for the activity improvement. With the aid of in situ electron paramagnetic resonance (EPR) spectra and quenching tests, hydroxyl radical (·OH), superoxide radical (O2•–), and singlet oxygen (1O2) are identified as the O3 catalytic decomposition products, while ·OH mainly accounts for NB mineralization. The detailed degradation route of NB was further investigated by the multi-chromatography analysis. NB is firstly oxidized into polyhydroxy compounds, followed by small molecular organic acids, and finally being mineralized into CO2 and H2O. This study established a facile strategy to synthesize highly active and stable Ce/SiO2 catalysts for catalytic ozonation, and elucidated the in-depth mechanisms for the activity origins of the Ce loaded silica-based materials in catalytic ozonation processes (COP).
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Nano Energy
·
2023
·
IF 17.6
Zijun Yi,Bo Xiao,Xin Li,Yubo Luo,Qinghui Jiang,Junyou Yang
The carrier non-radiative recombination loss caused by numerous interfacial defects existing between perovskite and neighboring charge transport layers, such as SnO 2 /perovskite and perovskite/spiro-OMeTAD, which greatly restricts the performance improvement of flexible perovskite solar cells (PSCs). Herein, we devised a novel dual-modification strategy using Ce-containing compounds (Ce 2 (SO 4 ) 3 and Ce(SO 4 ) 2 ) to minimize interfacial defect density at the interface of SnO 2 /perovskite and perovskite/spiro-OMeTAD respectively, thus enhancing the performance and stability of flexible PSCs. It was revealed that the introduction of Ce 2 (SO 4 ) 3 interface layer was conducive to ameliorating the electrical properties of SnO 2 and significantly reducing the SnO 2 /perovskite interface defects. Moreover, the Ce(SO 4 ) 2 was adopted as a novel oxidant to achieve the rapid oxidation of spiro-OMeTAD, thus enhancing the hole mobility of bulk spiro-OMeTAD and suppressing perovskite/spiro-OMeTAD interface defects. Therefore, reduced non-radiative recombination losses near the two interfaces of the perovskite layer could be achieved by such a novel and comprehensive modification strategy. In consequence, the Ce-modified flexible and rigid PSCs achieved excellent photoelectric conversion efficiency (PCE) of 19.34 % and 22.62 %, respectively. Notably, the optimized flexible PSCs exhibited outstanding mechanical durability, and 83.2 % of the initial PCE was maintained after 3000 bending cycles.
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Small
·
2022
·Vol. 18
·期 23
·2201200
·
IF 15.153
Peng Jing,Peixin Liu,Minghao Hu,Xuan Xu,Baocang Liu,Jun Zhang
Electrochemical nitrogen reduction powered by renewable electricity is a promising strategy to produce ammonia. However, the lack of efficient yet cheap electrocatalysts remains the biggest challenge. Herein, hybrid Cu 2 O-CeO 2 -C nanorods are prepared on copper mesh through a metal-organic framework template route. The Cu-loaded Ce-MOF is thermally converted to Cu 2 O-CeO 2 heterojunctions with interfacial Cu-[O X ]-Ce structures embedded in carbon. Theoretical calculations reveal the lower formation energy of oxygen vacancies in Cu-[O X ]-Ce structures than in the Cu 2 O or CeO 2 phase. The Cu-[O X ]-Ce structures with oxygen vacancies enable the formation of interfacial electron-rich Cu(I) species which show significantly enhanced performance toward electrocatalytic nitrogen reduction with an NH 3 yield of 6.37 × 10 −3 µg s −1 cm −2 and a Faradaic efficiency of 18.21% in 0.10 m KOH at −0.3 V versus reversible hydrogen electrode. This work highlights the importance of modulation of charge distribution of Cu-based electrocatalysts to boost the activity toward nitrogen reduction.
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PubMed
高影响因子
Molecular Catalysis
·
2022
·
IF 5.089
Yaping Yang,Xuesong Liu,Zhiming Sui,Yanghui Wang,Ping Fang,Peng Jiang,Xiaodong Wu
The purpose of this study is to investigate the interaction of Ce and W species with TiO 2 , Al 2 O 3 and SiO 2 supports, so as to illustrate the influence of supports and distribution of Ce, W species on SCR reaction. It is found that low-temperature activity followed the order of CeW > CeWTi > CeWAl > CeWSi. The reasons for the various activity of the catalyst were investigated by a series of characterization. The low-temperature NH 3 -SCR activity is associated with the surface concentrations of Ce 3+ , oxygen vacancies and active oxygen species, which are dominated by the dispersion and interactions of Ce/W species with the supports. Arising from interactions of Ti 4+ with high-density electron cloud, finely dispersed Ce and W species facilitate the W-Ce synergism and produce more active oxygen. All these contribute toTiO 2 can make Ce and W species in an ideal distribution, so the corresponding catalyst shows excellent NO x conversion of CeWTi catalyst at 200–350 °C. The reaction process observed by in situ DRIFT indicated that the NH 3 -SCR reaction on CeO 2 -WO 3 containing catalysts mainly follow Langmuir-Hinshelwood (L-H) mechanism at low temperature. Based on the analysis of the characterization and reaction process, it is concluded that the control step of NH 3 -SCR reaction at low temperature over CeO 2 -WO 3 containing catalysts is the adsorption and activation of NO x .
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JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Guiyang Xian,Ximing Zhang,Zhaolin Zhu,Yan Wang,Chongmei Wu,Yin Liu,Zhenying Liu,Xianglong Wan,Konghu Tian,Lingbing Kong
The excellent electromagnetic wave (EMW) absorption performance of metal organic frameworks (MOFs) has attracted a lot of attention. In this work, zeolitic imidazolate framework-67 (ZIF-67) was synthesized hydrothermally using 2-methylimidazole (2-mIm) as the organic ligand, cobalt nitrate hexahydrate (Co(NO 3 ) 2 ·6H 2 O) as the cobalt source and methanol (MeOH) as the organic solvent . The ZIF-67 was etched with cerium nitrate hexahydrate (Ce(NO 3 ) 3 ·6H 2 O), leading to rhombic dodecahedron Ce–Co/C composites with porous hollow structure after thermal annealing. In addition, the effect of the content of Ce(NO 3 ) 3 ·6H 2 O on EMW absorption performance of the Ce–Co/C composites was studied. Specifically, the sample Ce–Co/C-2 (Ce(NO 3 ) 3 ·6H 2 O): (ZIF-67 = 1:2) showed optimal EMW performance. For the Ce–Co/C-2 based composite with a filling ratio of 45 wt%, a RL min reached −64.67 dB at 11.12 GHz with a thickness of 2.21 mm. The promising EMW absorption performance of the porous hollow structure was attributed to its large specific surface area and massive defects, multiple reflection/scattering, improved impedance matching and increased dielectric loss. This work provides a reference improve EMW absorption performance of MOF materials through regulating their microstructures.
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