JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
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2019
·Vol. 94
·期 5
·1576-1584
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IF 2.659
Weijie Wen,Zhencheng Lou,Yanjin Chen,Dingsheng Chen,Shuanghong Tian,Ya Xiong
BACKGROUND Iron (Fe) 3+ has much a smaller ion radius than cerium (Ce) 4+ but praseodymium (Pr) ions have a similar radius to Ce ions with the same valence. Hence, it is interesting to tune the structural properties, including lattice deformation, band gap and oxygen vacancy (O v ), of CeO 2 by Pr and Fe codoping for enhanced visible-light catalytic activity. RESULTS A series of Ce 1-x-y Pr x Fe y O 2-σ ( x = 0∼0.012, y = 0.003∼0.031) nanoparticles were prepared by a simple one-step sol-gel method. The structural properties of CeO 2 , including crystal deformation (cell lattice from 5.4069 to 5.4195), band gap (from 2.20 to 2.93), oxygen vacancies (O v from 0.15% to 9.03%), and peroxide species (O 2 2− from 0.37% to 1.09%) can be finely tuned by Pr and Fe codoping. Among ten samples, Ce 0.982 Pr 0.003 Fe 0.015 O 2-σ with proper structural properties showed the highest photocatalytic activity towards the degradation of acid orange 7. The first reaction rate constant reaches 0.0687 min −1 , 9.3 and 7.7 times that of Ce 0.994 Pr 0.006 O 2-σ and Ce 0.985 Fe 0.015 O 2-σ , respectively. The mechanism was found to involve ·OH, ·O 2 − and photogenerated holes. CONCLUSION The structural properties of CeO 2 can be finely and easily tuned by Pr and Fe codoping. Thus, the photocatalytic activity of CeO 2 under visible light irradiation was boosted. © 2019 Society of Chemical Industry
研究领域:
材料科学
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光催化
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纳米材料
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环境化学
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DOI
高影响因子
Nanomaterials
·
2020
·Vol. 10
·期 5
·983
·
IF 4.324
Xueqing Zhu,Hui He,Yanxia Li,Haoyuan Wu,Mingli Fu,Daiqi Ye,Junliang Wu,Haomin Huang,Yun Hu,Xiaojun Niu
Functional metal organic framework (MOF) derivatives have attracted tremendous attention as promising catalysts for various reactions. The thermal decomposition strategies have a vital effect on the structures and physicochemical properties of functional MOF derivatives. Nevertheless, what effect does the pyrolysis strategy have on MOF derivatives need further study. In this work, one-step (under dry air) and two-step (first under N2and then dry air) pyrolysis are chosen to prepare the functional ceria-based MOF derivatives with novel hierarchical pore structure. In comparison with the derivatives prepared by one-step pyrolysis, the two-step pyrolysis composites exhibit better catalytic activity for toluene oxidation due to the higher contents of surface absorbed oxygen species and surface oxygen vacancies. The reusability and durability test demonstrates perfect stability of such functional MOF derivatives. The in-situ UV Raman reveals that two-step strategy is favorable for enhancing the gaseous oxygen activation ability of the functional MOF derivatives. Those findings may instruct the synthesis of functional MOF derivatives via different pyrolysis strategies as well as afford a further understanding of the crucial role of oxygen vacancies.Keywords:metal organic frameworks;functional derivatives;pyrolysis strategies;toluene oxidation;oxygen activation abilities
研究领域:
材料科学
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催化化学
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产品关联
DOI
PubMed
高影响因子
Catalysts
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2019
·Vol. 9
·期 10
·849
·
IF 3.444
Zeyu Xue,Zhaoping Zhong,Bo Zhang,Chao Xu
To investigate the catalytic pyrolysis performance of complex metal oxide catalysts for biomass, γ-Al2O3was prepared through the precipitation method, and then ZrO2and γ-Al2O3were blended in the proportion of 2:8 using the co-precipitation method. Next, CeO2was loaded on the surface of the catalyst for further modification. The three catalysts, A, ZA and CZA, were obtained. The specific surface and acidity of the catalysts were characterized by nitrogen adsorption–desorption and NH3-Temperature Programmed Desorption (NH3-TPD) respectively. The catalytic pyrolysis performance of catalysts for bamboo residues was investigated by Pyrolysis gas chromatography mass spectrometry (Py-GC/MS). Chromatograms were analyzed for identification of the pyrolysis products and the relative amounts of each component were calculated. Experimental results indicated that catalyst A had a good catalytic activity for the fast pyrolysis of bamboo residues. The addition of ZrO2and CeO2could continuously enhance the acidity of the catalyst and further promote the pyrolysis of macromolecular compounds and deoxidation of oxygen-containing compounds. Finally, catalyst CZA, obtained by compound modification, could not only dramatically reduce the relative content of phenol, acid and aldehyde and other oxygen-containing compounds, but also achieved the maximum hydrocarbon yield of 23.38%. The catalytic performance of catalyst CZA improved significantly compared with catalyst A.Keywords:biomass;pyrolysis;catalytic cracking;Py-GC/MS;complex metal oxides
研究领域:
能源与燃料化学
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催化化学
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产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
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2021
·
IF 5.909
Zhifei Hao,Guoquan Liu,Nan Ma,He Zhang,Yi Li,Yuguo Xia,Dongpeng Zhang,Sihui Zhan
Acidity and redox properties of the catalyst are two crucial factors affecting the performance of NH 3 -SCR. Herein, we design a novel WO x /Cu-CeO 2 oxide catalyst in which the WO x species are highly dispersed on the {111}/{100}-terminated surface of Cu-doped CeO 2 nanospheres , which exhibits great deNO x activity advantage and wide operating temperature window (200–400 °C, over 85% NO x conversion with a gas hourly space velocity (GHSV) of 60,000 h −1 ), as well as good sulfur resistance and N 2 selectivity . The relationship among the composition, acidity and redox properties of the WO x /Cu-CeO 2 catalyst is established in the NH 3 -SCR reaction. The combined experimental studies and spectroscopic characterization reveal that the introduction of Cu into the lattice of CeO 2 not only increases the surface Ce 3+ and oxygen vacancy concentration but also provides more sites for capture and dispersion of WO x species, thus mediating and improving the Lewis and Brønsted acid sites and reducibility of catalyst. XPS and DFT calculations further demonstrate that electronic interaction between WO x and Cu-doped CeO 2 is enhanced duo to the existence of interactions of short-range Ce-O-Cu and Ce-O-W. Moreover, the NH 3 -SCR reaction over WO x /Cu-CeO 2 may follow both Langmuir-Hinshelwood and Eley-Rideal reaction pathway according to the in situ DRIFTS.
研究领域:
催化化学
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环境科学
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产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2022
·
IF 9.965
Yonglong Huang,Yuzhou Liu,Yanzhu Deng,Jing Zhang,Beibei He,Jian Sun,Zhihong Yang,Wei Zhou,Ling Zhao
The coupling of oxygen evolution and reduction reactions (OER and ORR) plays a key role in rechargeable Zn-air batteries (ZABs). However, both OER and ORR still suffer from sluggish kinetics, even when using the mainstream precious metal-based catalysts. Herein, oxygen vacancies-rich CeO 2 decorated CoSe 2 nanocubes are proposed as a novel air electrode to drive OER and ORR for ZABs. The resultant CeO 2 coupled CoSe 2 nanocubes (CeO 2 @CoSe 2 -NCs) catalyst exhibits a significantly enhanced bifunctional activity relative to the pristine CoSe 2 -NCs and the pristine CeO 2 . Moreover, an assembled ZABs using this CeO 2 @CoSe 2 -NCs electrode delivers a high output power density of 153 mW cm −2 and a long-life stability over 400 cycles, superior to the benchmark Pt/C-IrO 2 electrode. Theoretical calculations reveal that the electronic interaction and oxygen vacancies in CeO 2 @CoSe 2 -NCs contribute to efficient oxygen electrocatalysis . This protocol provides a promising approach of constructing oxygen vacancies in hybrid catalysts for energy conversion and storage devices.
研究领域:
材料科学
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电化学
·
能源存储与转换
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产品关联
DOI
PubMed
高影响因子
Journal of Materials Research and Technology-JMR&T
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2023
·
IF 6.4
Jing-feng Wang,Jun-qi Li,Lin-zhu Wang,Chao-yi Chen,Xiang Wang,Fei Zhao
The large primary carbides in H13 steel significantly affect its service life. In this study, pre-dispersion technology is used to disperse CeO 2 nanoparticles, which are then introduced into H13 steel. The effects of CeO 2 nanoparticles on the inclusions, primary carbides, microstructures, and properties of H13 steel are investigated. Ce-containing inclusions with size of 0.5–2 μm are generated and distributed uniformly in H13 steel owing to the reduction of CeO 2 by Al and C. Both the dendrite structure and primary carbides in H13 steel are refined by CeO 2 nanoparticles. The secondary dendrite arm spacing decreases from 13.51 ± 2.34 to 6.90 ± 1.23 μm. The size and number of primary carbides decrease from 1 to 5 to 1–3 μm, and from 1125 to 725/mm 2 , respectively. This is attributable to the disregistry of Ce-containing inclusions and primary carbides/austenite. The segregation of alloy elements in H13 steel is calculated using the Clyne–Kurz model. The properties of H13 steel are improved via the addition of CeO 2 ; in particular, its tensile strength, total elongation rate, and hardness are 726.38 MPa, 23.43%, and 243.49, respectively, which corresponds to increases by approximately 5.58%, 8.27%, and 10.11%, respectively. The results can facilitate improvements to the performance of H13 steel and the development of rare earth steel.
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高影响因子
JOURNAL OF CATALYSIS
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2023
·
IF 7.3
Yiwen Zou,Lin Dong,Siyang Yan,Jiaxu Liu,Lili Mu,Licheng Li,Yue Hu,Haifeng Qi,Shanjun Mao,Zupeng Chen
Efficient and selective N -alkylation of amines with alcohols via transfer hydrogenation is of great significance but extremely challenging. Here, we report the production of N –benzylaniline (BZA) from benzyl alcohol and aniline over various fine-shaped Ru/CeO 2 catalysts. The Ru/CeO 2 –R (rod) catalyst exhibits the highest catalytic activity among all catalysts, in which the yield of BZA reaches up to 88% with complete conversion, significantly higher than that of Ru/CeO 2 -C (cube, 52%) and Ru/CeO 2 -O (octahedron, 32%). Extensive experimental investigations disclose that Ru nanoparticles with a metallic state promote the dehydrogenation of the hydroxyl group and hydrogenation of imines, while the CeO 2 –R with rich oxygen vacancies facilitates the adsorption and activation of reactants. Furthermore, kinetic studies and time-resolved operando dual-beam Fourier transform infrared spectroscopy analysis confirms the transfer hydrogenation pathway, in which the benzyl alcohol is firstly dehydrogenated to benzaldehyde, followed by spontaneously reacting with aniline, and finally transforms into the N -benzylaniline rapidly.
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高影响因子
SENSORS
·
2023
·Vol. 23
·期 23
·9605
·
IF 3.9
Wenna Zhang,Qiu Sun,Xuelin Zhang,Weijian Yuan,Jianfeng Wu
In this work, a flexible electrochemical sensor was developed for the detection of organophosphorus pesticides (OPs). To fabricate the sensor, graphene was generated in situ by laser-induced graphene (LIG) technology on a flexible substrate of polyimide (PI) film to form a three-electrode array, and pralidoxime (PAM) chloride was used as the probe molecule. CeO2was used to modify the working electrode to improve the sensitivity of the sensor because of its electrocatalytic effect on the oxidation of PAM, and the Ag/AgCl reference electrode was prepared by the drop coating method. The effects of the laser power, laser scanning speed, and CeO2modification on the electrochemical properties of the sensor were studied in detail. The results prove that the sensor has good repeatability, stability, and anti-interference ability, and it shows an excellent linear response in the chlorpyrifos concentration range from 1.4 × 10−8M to 1.12 × 10−7M with the detection limit of 7.01 × 10−10M.Keywords:laser-induced graphene;electrochemical sensor;organophosphorus pesticide;pralidoxime chloride;cerium dioxide
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2018
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IF 4.229
Ying-Hua Zhou,Zhiyan Zhang,Suqin Wang,Nicholas Williams,Yong Cheng,Shizhong Luo,Jing Gu
The hydrogen economy is a proposed system that utilizes hydrogen to deliver energy. For the realization of this concept, how to safely, controllably and reversibly store and release hydrogen are critical problems which must be resolved. Metal alloys combined with suitable support materials are widely applied to various catalytic reactions . Here palladium nickel bimetallic nanoparticles doped with cerium oxide on a reduced graphene oxide (rGO) support were prepared by combining metal ion precursors and graphene oxide in a one-pot co-reduction approach. The as-received catalysts were characterized by XRD , TEM, SEM, XPS and ICP-OES, and the results revealed that PdNi-CeO 2 nanoparticles were uniform dispersal on rGO. The as-synthesized PdNi-CeO 2 /rGO had been adopted as a heterogeneous catalyst for the hydrogen evolution from the hydrolysis of ammonia borane (NH 3 BH 3 , AB) at room temperature . Kinetically, the hydrogen-release rate was first-order with the increased concentration of catalysts. The optimized catalyst of Pd 0.8 Ni 0.2 -CeO 2 /rGO with the CeO 2 content of 13.9 mol% exhibited an excellent activity with a turnover frequency value of 30.5 mol H 2 (mol catalyst) −1 min −1 at 298 K, and a low apparent activation energy ( E a ) of 37.78 kJ mol −1 . The robust catalytic performance of the Pd 0.8 Ni 0.2 -CeO 2 /rGO is attributed to the uniform controlled nanoparticle size, the synergic effect between the nanoparticles bimetallic properties, and the effective charge transfer interactions between the metal and support.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2023
·
IF 6.6
Mingkai Chen,Yanjun Ma,Lei Chen,Dingjun Zhang,Huidi Zhou,Jianmin Chen
The coupling effect of wear and corrosion aggravates the damage and failure of key moving parts of high-end equipment, leading to a significant reduction in their service life. In present work, a functional integrated composite coating with exceptional corrosion resistance and tribological properties was developed by utilizing the responsive corrosion inhibition of nano‑cerium oxide (nano-CeO 2 ) and the low surface energy and low shear characteristics of polytetrafluoroethylene (PTFE). The tribological behaviors and corrosion protection performance of coatings on aluminum alloy 2024 were evaluated and the corrosion inhibition mechanism was further discussed. The results revealed that Ce 3+ on the surface of nano-CeO 2 reacts with OH − generated by the REDOX reaction of the cathode to produce a uniform and stable passivation film, which can effectively improve the corrosion resistance of the metal matrix. Notably, the most obvious passivation effect is presented when the 2 % addition of nano-CeO 2 as the larger low-frequency impedance modulus of 4.49 × 10 10 Ω·cm 2 and higher phase angle of 88°. The introduction of PTFE not only changes the coating from hydrophilic to hydrophobic, but also further improves the shielding properties of the coating. The low-frequency impedance modulus of the coating further increases by an order of magnitude to 2.38 × 10 11 Ω·cm 2 , and its neutral salt spray resistance exceeds 210 days. Besides, the friction coefficient is reduced by 77.43 % and the wear resistance improved by 6.8 times compared with phenolic epoxy coating. Due to the enhancement and corrosion inhibition effect of nano-CeO 2 , the lower friction coefficient (0.044) and good wear resistance are further presented under the corrosive medium condition of 3.5 % NaCl solution.
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DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2023
·
IF 4.8
Yifei Li,Yucui Zhang,Huan Jiang,Mengyao Qi,Xia Zhang,Baowang Zhu,Lei Han
Although the fact that H 2 O 2 is employed in the medical, food, and chemical industries, trace detection of H 2 O 2 remains a difficult and significant problem. For the detection of H 2 O 2 residues, SERS assays based on enzyme inhibition techniques show promise. As a result, we csynthesized CeO 2 @nanogel/Au nanoparticles with dual enzyme-like capabilities to detect hydrogen peroxide in this study. CeO 2 nanozymes possess both peroxidase-like and oxidase-like activities which could oxidize colorless 3,3′,5,5′-tetramethylbenzidine to blue TMB oxide. Surprisingly, after the addition of nanogel, CeO 2 @nanogel were prepared and both of its dual enzymatic activities decreased, especially the oxidase-like enzymes almost disappeared. To better investigate the enzyme catalytic activity, Au NPs were introduced and CeO 2 @nanogel/Au nanozymes were self-assembly prepared. Based on the significantly enhancement of CeO 2 @nanogel/Au nanozymes peroxidase activity, we developed a Raman detection method for H 2 O 2 with TMB ox as the probe molecule. The Raman intensity showed good linearity for the concentration of H 2 O 2 in the range of 10 -9 M−10 −1 M with a correlation coefficient of R 2 = 0.9922 and a detection limit of 2.68 × 10 -12 M. Thus, the proposed SERS mode sensor exhibited good selectivity and interference resistance, providing a new avenue for environmental monitoring.
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高影响因子
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 43
·19974-19982
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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.
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高影响因子
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