APPLIED CATALYSIS B-ENVIRONMENTAL
·
2020
·
IF 16.683
Lixia Li,Juanhua Kong,Huimin Zhang,Sijie Liu,Qiang Zeng,Yaqin Zhang,Hao Ma,Hongyan He,Jinxing Long,Xuehui Li
The catalytic depolymerization process for lignin to produce value added chemicals is often challenged by the limited mass transfer over heterogeneous catalysts, the complex aromatic biopolymer structures, and the high recalcitrance of C C bonds. Herein, a series of hierarchical MFI nanosheets (MFI-ns) supported metal oxide catalysts have been designed and used for the selectively oxidative cleavage of organosolv lignin. As expected, 81.6 % conversion of lignin can be achieved over 15Ce-5Cu/MFI-ns with 294.0 mg g −1 yield of volatile products, including 180.9 mg g −1 of diethyl maleate. Quantum chemistry calculation coupled with static adsorption measurements shows that the superior catalytic activities of these catalysts are ascribed to the favorable mass transport of lignin to the active sites by the unique layer structure, and the hierarchical pore sizes distribution, as well as the electronic effect between Cu and Ce components. In addition, the catalytic mechanism for the cleavage of C C bonds in β -O-4 model probes has been studied via the controlled oxidative degree of model compounds and the isotope-labeling experiments. Therefore, this work provides a new insight into the efficient utilization of lignin via the rational design of catalysts.
✓ 已验证
产品关联
DOI
高影响因子
ACS ES&T Engineering
·
2021
·
IF 0
Ying Liu,Yulin Yang,Wei Miao,Ningjie Du,Dandan Wang,Hehe Qin,Shun Mao,Kostya Ken Ostrikov
Electro-Fenton (EF) is one of the promising clean and renewable technologies for organic pollutant control. However, insufficient hydrogen peroxide (H2O2) generation and the subsequent hydroxyl radicals (•OH) conversion still prevent the wide applications of EF. Herein, we report a Ce-doped vertically aligned α-FeOOH nanoflakes anchored on a carbon felt (CF) cathode for EF operation. In this system, a high concentration H2O2 (113.6 mg/L on 4 cm2 cathode) is generated in 60 min, and being efficiently catalyzed to •OH by virtue of the active nanoedge (1.6 nm thickness) of Ce-doped α-FeOOH. The •OH production rate is calculated as high as 4.2 mM/W/cm2/min, which is ∼6.6-fold higher compared with the unmodified CF electrode. Moreover, this novel cathode achieves a complete removal (100% removal rate) of ultrahigh concentration chloramphenicol (1.1 mM, 355 mg/L) in 8 h and a high mineralization rate (94%) in 29 h in a scaled-up EF system. Density functional theory calculations (DFT) reveal that the Ce doping in α-FeOOH greatly promotes the conversion of H2O2 into •OH. This study not only offers a novel cathode structure for EF process but also opens radically new prospects for applied environmental catalysis.
✓ 已验证
产品关联
DOI
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2019
·Vol. 166
·期 13
·D638
·
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.
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Xiaoqiang Wang,Yue Liu,Zhongbiao Wu
In this paper, the Cu-Ce based catalyst using NbOPO 4 (Nb-P) as support was firstly employed for selective catalytic reduction (SCR) of NO by NH 3 . The experimental results had illustrated that such catalyst exhibited well SCR activity and N 2 selectivity within a wide temperature range of 200–450 °C. These superior performances could be mainly attributed to its improved textural properties and strong acidity derived from NbOPO 4 support. More importantly, the sulfur tolerance of the NbOPO 4 supported Cu-Ce sample was found greatly improved compared to TiO 2 and Ti-Nb supported samples, where above 80% SCR activity of Cu-Ce/Nb-P sample was obtained at 250 °C after 10 h reaction running in the presence of 100 ppm SO 2 . This fact was the result of the enhanced acidity and the strong interactions between Cu-Ce oxides and NbOPO 4 support, which could prevent the surface oxygen species from sulfation by SO 2 . As such, these oxygen species strongly associated with NbOPO 4 support still could activate adsorbed NH 3 to fulfill the SCR reaction cycle, leading to its better sulfur resistance. The work would provide some enlightenments to the development of NH 3 -SCR catalysts with high sulfur resistance at medium-high temperature.
✓ 已验证
产品关联
DOI
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 .
✓ 已验证
DOI
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.
✓ 已验证
产品关联
DOI
高影响因子
TALANTA
·
2013
·
IF 3.498
Bing-bing Sun,Li Qi,Xiao-yu Mu,Juan Qiao,Ming-lin Wang
A facile chiral ligand exchange capillary electrophoresis (CLE-CE) system with Zn(II)- l -alanine as the chiral selector in the presence of β-cyclodextrin has been developed for enantioseparation of dansyl amino acids . The influence of the key factors, such as buffer pH, the ratio of Zn (II) to ligand, the concentration of β-cyclodextrin and the concentration of the complex, were investigated in detail when d , l -Tyr and d , l -Thr were selected as the model analytes. The proposed method showed favorable quantitative analysis property of dansyl d , l -tyrosine with good linearity ( r 2 ≥0.999) and reproducibility (RSD≤3.8%), then, it was applied in studying the activity of tyrosinase through the determination of l -tyrosine concentration variation after being incubated with the enzyme. Further, the inhibitory efficiency of kojic acid and soy sauce on the tyrosinase was investigated. The IC 50 of kojic acid obtained from the sigmoidal inhibitory curve was 21.35 μM. The results imply that the proposed CLE-CE system has the potential in exploring the activity of enzyme and screening the inhibitors of enzyme.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Particuology
·
2017
·
IF 2.621
Chun Shen,Kexia Pang,Le Du,Guangsheng Luo
A facile and green method to prepare Ce-doped TiO 2 nanoparticles supported on porous glass beads is reported. An ion exchange process and subsequent calcination yielded Ce-doped TiO 2 nanoparticles with a mean size of 4.8 ± 0.3 nm. The nanoparticles were dispersed on the surface of porous glass beads. The addition of Ce enhanced the visible light absorption of the TiO 2 nanoparticles in the 400–500 nm spectral window. The band gap of the as-prepared catalyst was 2.80 eV. The Ce-doped TiO 2 nanoparticles immobilized on porous glass beads exhibited excellent photocatalytic activity for the visible-light-degradation of methyl orange (MO) and rhodamine B (RhB); with rate constants of 0.095 and 0.230 min −1 ; respectively. The effects of Ce dosage; reaction duration; and initial solution pH on the conversion of MO and RhB dyes were investigated. The green synthesis and favorable photocatalytic activity makes the Ce-doped TiO 2 nanoparticles immobilized on porous glass an attractive alternative for the efficient degradation of organic pollutants.
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2017
·
IF 4.798
Jia Liu,Jinshuo Qiao,Hong Yuan,Jie Feng,Chao Sui,Zhenhua Wang,Wang Sun,Kening Sun
Ni modified Ce 0.6 Mn 0.3 Fe 0.1 O 2 (Ni-CMF) material is evaluated as an anode material for hybrid direct carbon fuel cell (HDCFC). The Temperature Programmed Reaction (TPR) and GC test results show that the Ni additive significantly promotes the oxidation of carbon and consequently accelerates the formation rate of CO. Moreover, the Ni-CMF material is found to show a high electrical conductivity compared to pure CMF in HDCFC operating conditions. Taking advantage of the excellent catalytic activity and high conductivity, the electrolyte-supported HDCFC with Ni-CMF anode shows a high maximum power density of 580.7 mW cm −2 at 800 °C, when activated carbon is used as the fuel. Furthermore, the cell displays good stability under galvanostatic operation at current density of 50 mA cm −2 at 750 °C. These results indicate that the designed Ni-CMF composite material has the potential to be developed as an alternative anode for HDCFCs.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Inorganic and Organometallic Polymers and Materials
·
2016
·Vol. 27
·期 1
·249-256
·
IF 1.308
Du Sen,Wang Luyan,Xue Ni,Wu Ting,Pei Meishan,Sui Weiping,Guo Wenjuan
Modified bentonite was prepared by grafting poly(2-(acryloyloxy)ethyl)trimethyl ammonium chloride by a Ce(IV)-redox process to remove an anionic dye, brilliant yellow (BY). The BY removal efficiency changed with pH, temperature and reaction time. The adsorption capacity for BY decreased slightly with value of pH enhanced from 2.0 to 10.0 in solution. Kinetics models and isotherms models were used to match the adsorption behavior. Adsorption kinetics showed the adsorption was a fast course, achieving balance within 180 min and could be described well by the pseudo-second-order model. The thermodynamic equilibrium data showed that the adsorption isotherm matched with Langmuir model. Results represented that the adsorption capacity increased greatly by grafting PDAC on bentonite and the maximum adsorption capacity could reach to 302.9 mg/g.
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Dingran Li,Huimin Zhang,Juntao Xie,Yaohua Li,Yang Ma,Aimin Chang
The La 1-x Ce x BaCo 2 O 5 (x = 0.05, 0.1, 0.15, 0.2) thermosensitive ceramics with negative temperature coefficient (NTC) were synthesized using a conventional solid-phase method. X-ray diffraction analysis (XRD) revealed that La 1-x Ce x BaCo 2 O 5 possesses an orthorhombic perovskite structure. Scanning electron microscopy (SEM) showed a uniform and dense ceramic microstructure, with grain size initially increasing and then decreasing as the Ce content rises. X-ray photoelectron spectroscopy (XPS) data reveal the presence of oxygen vacancies and Co 3+ /Co 2+ ion pairs within the material, showing concentrations that increase with Ce content. The resistance temperature profiles indicate the presence of a hybrid conductive mechanism in the material. In the temperature range of 2–20 K, the conductive mechanism of the material conforms to Mott's 3D VRH conduction model. When the temperature is 20–77 K, the conductive mechanism of the material is consistent with the small polariton conduction model. In addition, the mechanism of the mixed effect of oxygen vacancy concentration on the conductivity of the material is explained to elucidate the electron hopping transport conductivity mechanism of NTC thermal ceramics. First-principle calculations demonstrate that oxygen vacancies introduce new impurity energy levels and pathways for electron transport, enhancing the ceramics' electrical conductivity. These findings highlight the ceramic samples' favorable NTC characteristics and electrical conductivity across the temperature range 2–77 K, offering new possibilities for applications in extremely low-temperature NTC thermistors.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Yize Li,Weiqiang Zhou,Zian Huang,Qinxue Pan,Xueqian Zhao,Mingming Zhang,Xiaojing Hao,Danqin Li,Jingkun Xu
Tungsten trioxide (WO 3 ) is recognized as a promising anode material for asymmetric supercapacitors (ASCs), yet its low conductivity and stability as well as energy density greatly limit its development. Herein, a flexible Ce-doped WO 3 (Ce 1.5% -WO 3 ) nanowire array with rich oxygen vacancies is grown on carbon cloth by a solvothermal synthesis. The specific capacitance of Ce 1.5% -WO 3 is 493F g −1 at 4 A/g and remains 90.4 % after 5000 cycles, superior to that of WO 3 nanowire arrays (416F g −1 , 80.3 %). The improved performance mainly stems from the synergistic effects of more oxygen vacancies, higher specific surface area, wider lattice spacing, faster ion diffusion, and electron transport generated by Ce doping. As-prepared ASC device can reach an energy density of 31.7 Wh kg −1 at a power density of 700 W kg −1 . Furthermore, two flexible soft-packaged ASCs connected in series can illuminate different electronic devices. This strategy proves the great application prospect of Ce-doped WO 3 nanowire arrays flexible electrodes in supercapacitors.
✓ 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）