Catalysts
·
2018
·Vol. 8
·期 12
·642
·
IF 3.465
Yan Gao,Tao Luan,Mingyang Zhang,Wenke Zhang,Wenchen Feng
A series of Mn−Fe−Ce−Ox/γ-Al2O3nanocatalysts were synthesized with different Mn/Fe ratios for the catalytic oxidation of NO into NO2and the catalytic elimination of NOxvia fast selective catalytic reduction (SCR) reaction. The effects of Mn/Fe ratio on the physicochemical properties of the samples were analyzed by means of various techniques including N2adsorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), H2-temperature-programmed reduction (TPR), NH3-temperature-programmed desorption (TPD) and NO-TPD, meanwhile, their catalytic performance was also evaluated and compared. Multiple characterizations revealed that the catalytic performance was highly dependent on the phase composition. The Mn15Fe15−Ce/Al sample with the Mn/Fe molar ratio of 1.0 presented the optimal structure characteristic among all tested samples, with the largest surface area, increased active components distributions, the reduced crystallinity and diminished particle sizes. In the meantime, the ratios of Mn4+/Mnn+, Fe2+/Fen+and Ce3+/Cen+in Mn15Fe15−Ce/Al samples were improved, which could enhance the redox capacity and increase the quantity of chemisorbed oxygen and oxygen vacancy, thus facilitating NO oxidation into NO2and eventually promoting the fast SCR reaction. In accord with the structure results, the Mn15Fe15−Ce/Al sample exhibited the highest NO oxidation rate of 64.2% at 350 °C and the broadest temperature window of 75–350 °C with the NOxconversion >90%. Based on the structure–activity relationship discussion, the catalytic mechanism over the Mn−Fe−Ce ternary components supported byγ-Al2O3were proposed. Overall, it was believed that the optimization of Mn/Fe ratio in Mn−Fe−Ce/Al nanocatalyst was an extremely effective method to improve the structure–activity relationships for NO pre-oxidation and the fast SCR reaction.
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ADVANCED ENGINEERING MATERIALS
·
2025
·Vol. 28
·期 2
·e202501970
·
IF 3.3
Zhishuai Liu,Siran Wang,Yujia Liu,Junwei Sha,Rui Li,Xudong Yang
Achieving the stability of pore structure and the enhancement of mechanical properties is the prominent target for aluminum (Al) foam design. In this work, the effects of manganese (Mn) content on the pore structure, mechanical properties, and deformation behavior of Al Mn foams are investigated. The results show that the appropriate addition of Mn (1.5 wt%) achieves a remarkable balance between energy absorption capacity (4.37 MJ m −3 ) and pore uniformity (standard deviation of 0.95 mm in average pore size), representing substantial enhancements of 193.28% in yield strength and 385.56% in energy absorption capacity compared to pure Al foams. These enhancements are attributed to a refined pore architecture, finely dispersed Al 6 Mn precipitates, and a sequential collapse mechanism, which collectively enable progressive energy dissipation. The application of the entropy weight method is pioneered in this study to establish a predictive framework for multiobjective design, demonstrating that energy absorption and pore uniformity are crucial factors for the matrix design of Al foams. These findings offer a potential strategy for future engineering applications of metal foam design.
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Molecular Catalysis
·
2018
·
IF 0
Gui Liu,Lei Sun,Wei Luo,Yue Yang,Junhua Liu,Fang Wang,Curtis J. Guild
Aerobic Baeyer-Villiger oxidation of ketones into corresponding esters were performed over mesoporous Mn-Ce and Mn-Co composite oxides prepared by co-impregnation method and benzaldehyde was used as the sacrificing agent. It was found that the best conversion and selectivity were obtained when the Mn/Ce mole ratio was 1:2 (denoted as Mn 0.33 Ce 0.67 O s ) through investigating the effect of Mn/Ce mole ratio on the catalytic activity. Interestingly, Mn 0.33 Co 0.67 O s (Mn/Co mole ratio was 1:2) catalyst had no catalytic activity for this reaction. X-ray diffraction (XRD) results showed that MnO x was completely dissolved into the CeO 2 lattice, and Mn 0.33 Co 0.67 O s sample was existed in the form of spinel structure (Co, Mn) (Mn, Co) 2 O 4 and obvious peaks of Co 3 O 4 . Nitrogen adsorption-desorption measurements revealed that Mn 0.67 Ce 0.33 O s , Mn 0.5 Ce 0.5 O s , Mn 0.33 Ce 0.67 O s and Mn 0.33 Co 0.67 O s materials possessed mesoporous structure. X-ray photoelectron spectroscopy (XPS) analysis showed that the highest concentration of Ce 3+ on the surface of Mn 0.33 Ce 0.67 O s catalyst, which could create unsaturated chemical bonds, charge imbalance, and oxygen vacancies on the surface of samples, it is beneficial to the oxidation reaction. Additionally, XPS data revealed that Mn 0.33 Ce 0.67 O s catalyst has great potential in catalytic oxidation due to the large amount of active oxygen species on the surface. In addition, manganese and cobalt species on the surface of Mn 0.33 Co 0.67 O s are almost present in the form of Mn 2+ and Co 3+ , it is known that Mn 2+ can serve as a potent antioxidant and scavenge the activity of active oxygen species, while Co 3+ ions can prevent the formation of oxygen vacancies and inhibit the release of reactive oxygen species, thus the presence of Mn 2+ and Co 3+ inhibited the catalytic activity of Mn 0.33 Co 0.67 O s catalyst. The diffuse reflectance ultraviolet-visible spectroscopy (DR-UV-vis) and hydrogen temperature-programmed reduction (H 2 -TPR) results are in accordance XPS data.
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Food Analytical Methods
·
2013
·Vol. 7
·期 2
·291-297
·
IF 1.969
Wen Shengping,Zhu Xiashi
A simple and rapid method based on dispersive liquid–liquid microextraction with room temperature ionic liquid 1,3-dibutylimidazolium hexafluorophosophate ([BBIM][PF 6 ]) coupled to flame atomic absorption spectrometry was developed for the speciation of Mn(II)/Mn(VII) in tea samples. The main factors affecting dispersive liquid–liquid microextraction were investigated in detail. Mn(II) and total manganese [Mn(II)+Mn(VII)] were quantitatively extracted after adjusting aqueous sample solution to pH 10.0 and 7.0, respectively. Mn(VII) was calculated by subtraction of Mn(II) from total manganese. Under the optimized conditions, the limits of detection (3 σ ) for Mn(II) and Mn(VII) were 0.26 and 1.86 ng/mL, and their relative standard deviations were 2.6 and 4.8 % ( n = 7, c = 25.00 ng/mL). The proposed method was validated by the determination of Mn(II) and Mn(VII) in the certified reference material [GBW(E)08513] of tea sample and different local tea samples with satisfactory results.
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ARCHIVES OF MICROBIOLOGY
·
2022
·Vol. 204
·期 3
·1-14
·
IF 2.667
Chen Sha,Ding Zhexu,Chen Jinyuan,Luo Jun,Ruan Xiaofang,Li Zongpei,Liao Fengfeng,He Jing,Li Ding
Bacterial non-enzymatic Mn(II) oxidation involving reactive oxygen species (ROS) (i.e., indirect oxidation), initially discovered from a marine alpha-proteobacterium, is believed to be of importance in controlling biogeochemical cycles. For soil-borne bacteria, however, evidence of indirect Mn(II) oxidation remains unclear. In this study, the indirect Mn(II) oxidation was evidenced in a soil-borne bacterium, Providencia sp. LLDRA6. First, with and without 50 mM of Mn(II) exposure for LLDRA6, 300 differentially expressed genes were found to be linked to Mn(II) exposure via transcriptome sequencing. Among them, an operon, responsible for phenylacetic acid catabolism, was sharply upregulated in transcription, drawing us a special attention, since its transcriptional upregulation has recently shown to be important for withstanding ROS. Next, a fluorometric probe, 2′,7′-Dichlorofluorescin diacetate (DCFDA), was used to qualitatively detect ROS from cells, showing a distinct increase in fluorescence intensities of ROS during Mn(II) exposure. Furthermore, concentrations of superoxide and hydrogen peroxide from cells were detected, respectively, with and without Mn(II) exposure, exhibiting that when Mn(II) oxidation occurred, superoxide concentration significantly increased but hydrogen peroxide concentration significantly decreased. Particularly, superoxide produced by LLDRA6 was proven to be the oxidant for Mn(II) in the formation of Mn oxides. Finally, we predicted links between phenylacetic acid metabolism pathway and ROS during Mn(II) exposure, proposing that the excessive ROS, generated in response to Mn(II) exposure, transcriptionally activate phenylacetic acid catabolism presumably by increasing concentrations of highly reactive oxepins.
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Advanced Materials Technologies
·
2026
·
IF 6.2
Peng Zhang,Hongyan Sun,Wei Zhang,Jiaying Zhang,Bo Chen,Adil Farooq Lodhi,Chan Li,Zijin Zeng,Chutian Wang,Yuguo Dai,Jiapeng Yang,Yinyan Wang,Tao Jiang,Lin Feng
Recent studies highlight piezocatalytic therapy (PCT) as a superior curative strategy owing to its stable dynamic control compared to sonoluminescence-activated sonodynamic therapy (SDT). However, most nano-piezoelectric catalysts' catalytic efficiency in biosafety and biocompatibility is unsatisfactory. Herein, this study modifies the typical piezoelectric material tetragonal barium titanate (T-BTO). It introduces novel manganese (Mn) -coated T-BTO nanoparticles (MCTB) that possess magnetic resonance imaging (MRI) ability and enhanced PCT effects. The encapsulation of Mn masks the piezoelectric effect of the nanoparticles, and the acidic tumor microenvironment (TME) triggers the stripping of Mn and restoration of the piezoelectric effect of T-BTO, which produces ROS under ultrasonic irradiation. The presence of Mn ions also enhances the MRI property of the tumor site as a contrast agent. Additionally, ultrasonic irradiation promotes the conversion of low-valence Mn into a high-valence state, further stimulating ROS production. The biosafety, therapeutic effects, T1-weighted MRI, and piezoresponse of MCTB are investigated in vitro. Animal studies also indicate that the nanoparticles display good treatment performance when activated by ultrasound and guided by MRI. Therefore, this study develops an MCTB particle that boosts ROS generation, enables tumor-specific ROS release, and enhances T1-weighted MRI, offering a safe PCT approach for tumors.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2026
·
IF 9
Bo Song,Zhenxing Shen,Zitong Wang,Qin Peng,Jia Liu
Traditional Mn-based NH 3 -SCR catalysts have a narrow temperature window, limiting low-temperature use. In this work, Mn@N-7 was prepared by a simple hydrothermal method using potassium permanganate and urea. The hydrothermal conditions are much milder than those used for most Mn-based catalysts. Graphite felt (GF) serves as a green support, providing a 3D carbon fiber network for uniform growth of manganese oxide nanowebs. Its high surface area (83.10 m 2 g −1 ) and open channels promote active species dispersion and fast mass transfer. The strong carbon framework prevents sintering at high temperatures. Mn@N-7 shows nearly 100% NO conversion at 100–200 °C and maintains good activity for 30 h. Its estimated cost is 1.2–1.8 USD kg −1 , lower than 3.0–4.5 USD kg −1 for V 2 O 5 -WO 3 /TiO 2 catalysts. The mild hydrothermal process avoids high-temperature calcination. This work demonstrates GF is a sustainable support and offers guidance for carbon-based catalysts in clean air applications.
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INORGANIC CHEMISTRY COMMUNICATIONS
·
2026
·
IF 5.9
Tianchi Zhang,Yaoting Wen,Chenglong Xia,Xuhui Xu,Guoping Wang,Yongcai Zhang
Developing efficient, recyclable heterogeneous catalysts for the oxidation of p-methoxytoluene (p-MT) remains a critical challenge in industrial organic synthesis. Herein, a ternary Co-Mn-Ce oxide catalyst was synthesized via co-precipitation and systematically optimized to address limitations in mass transfer and catalyst reusability. By modulating the Ce content, the structural evolution from cobalt‑manganese spinel phases to CeO 2 -dominated crystallites was demonstrated, significantly influencing catalytic performance. The CoMn 3 Ce 1.9 catalyst with high Ce loading exhibited a p-MT conversion of 95.0% under mild conditions, outperforming the low-Ce analogs, which showed only 50–60% p-MT conversion. Characterization revealed that CeO 2 -rich catalysts featured larger average pore sizes (18 nm vs. 2–4 nm for spinel-dominated systems), mitigating diffusion constraints and enhancing oxygen activation. High-concentration experiments (8 mL p-MT) maintained 77.7% conversion after 12 h, but with increased esterification to p-methoxybenzyl acetate (p-MBAc). Remarkably, the catalyst retained >70% activity over four runs. This work highlights the optimized pore architecture in overcoming traditional limitations of spinel-based catalysts, offering a sustainable, scalable strategy for aromatic aldehyde synthesis. The findings provide critical insights into designing multifunctional heterogeneous catalysts for selective C(sp 3 )-H bond activation, with broad implications for green chemical manufacturing.
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LANGMUIR
·
2022
·
IF 4.331
Chenming Han,Xiaoyan Yuan,Lixia Ren
A magnetic surfactant, which combines the properties of a surfactant with magnetic responsiveness, shows great potential in biotechnology, separation, adsorption, and catalysis, especially in non-invasive manipulation through a magnetic field. However, a molecularly magnetic surfactant is usually paramagnetic for the amorphous and less ordered structures. In this work, magnetic surfactant 1-methyl-3-hexadecane-imidazolium [MnCl2Br] (C16M[Mn]) is reported to self-assemble in water. The C16M[Mn] magnetic surfactant self-assembles in water to form a lamellar hydrogel from 10 to 50 wt % at and below room temperature. The hydrogel changes from a gel to a sol at 30 °C, and the hexadecane chains in the hydrogel change from noncrystalline to crystalline at 0 °C. In the hydrogel state, the lamellar domain spacing is varied from 36 to 45 nm depending on the concentration and self-assembly temperature. After self-assembly, the magnetic susceptibility of the freeze-dried magnetic surfactant is increased. Most important is the fact that the freeze-dried sample at a high concentration (40–50 wt %) shows the highest magnetic susceptibility, which is related to the closer molecular packing and the more ordered structures. The self-assembly-induced increase in magnetic susceptibility provides a method for improving the magnetic properties of a magnetic surfactant.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2022
·Vol. 33
·期 19
·15520-15532
·
IF 2.779
Zhang Xiaoyan,Yang Xu,Wang Zhaopeng,Pan Qi,Chu Baojin,Zuo Ruzhong
Our previous work proposed that except for ferromagnetic and piezoelectric properties, mechanical quality factor is also an important parameter for high magnetoelectric response of BiFeO 3 -based multiferroic ceramics. In this work, in order to improve the mechanical quality factor of BiFeO 3 -based ceramics and obtain higher magnetoelectric response, we use Mn as a dopant and prepare 0.75BiFe 1− x Mn x O 3 -0.25BaTiO 3 ( x = 0, 0.0025, 0.005, 0.0075, 0.01) ceramics. The dielectric, piezoelectric, magnetic, and magnetoelectric properties of the ceramics with different Mn doping levels and different sintering temperatures are studied comprehensively. We find that the piezoelectric response, mechanical quality factor, ferromagnetic property, and magnetoelectric response can be improved by optimization of the composition and sintering temperature of the ceramics. A large magnetoelectric coefficient α E \(\sim\) 2 V/(cm Oe) is achieved at resonant frequency when doping content of Mn is 0.75 mol% and sintering temperature is 1030 \(\mathrm{^\circ{\rm C} }\) . Such high value of α E is attributed to the combined effect of improved mechanical quality factor, high piezoelectric coefficient, and enhanced ferromagnetism. It is among the largest α E values obtained in single-phase BiFeO 3 -based ceramics. Moreover, our work further verifies the mechanical quality factor is an important parameter to achieve a high magnetoelectric response in BiFeO 3 -based ceramics.
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APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Zongyun Mu,Ting Guo,Hao Fei,Yaoqing Mao,Zhuangzhi Wu,Dezhi Wang
Rational design of robust and highly efficient electrocatalysts for hydrogen evolution reaction (HER) is crucial for the development of energy conversion technologies. Molybdenum phosphide (MoP) has displayed excellent HER activities and triggered substantial interests as a promising water splitting electrocatalyst. In this work, a Mn doping strategy is proposed to improve the HER performances of MoP for the first time as well as the construction of novel porous interconnected structures. And the effect of doping contents and corresponding improvement mechanism are also discussed. It is found that the obtained 0.05Mn-MoP catalyst with porous interconnected nanosheets (NSs) presents the best HER properties as well as outstanding durability. The porous interconnected structures offer more exposed active sites, and the Mn doping optimizes the electronic configuration of MoP, leading to lower charge transfer resistance and higher intrinsic activity. This work provides a facile method to construct porous structures and demonstrate the effective strategy of Mn doping for the enhancement of MoP for the HER.
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Nanomaterials
·
2019
·Vol. 9
·期 11
·1520
·
IF 4.034
Lei Qiu,Jiaxiong Xu,Xiao Tian
Ag and Mn dopants were incorporated into Cu2ZnSnS4thin film to reduce defects in thin film and improve thin film properties. Sol–gel and spin-coating techniques were employed to deposit Ag and Mn co-doped Cu2ZnSnS4thin films. The structures, compositions, morphologies, and optical properties of the co-doped thin films were characterized. The experimental results indicate the formation of kesterite structure without Ag and Mn secondary phases. The amount of Ag in the thin films is close to that in the sols. The co-doped Cu2ZnSnS4thin films have an absorption coefficient of larger than 1.3 × 104cm−1, a direct optical band gap of 1.54–2.14 eV, and enhanced photoluminescence. The nonradiative recombination in Cu2ZnSnS4thin film is reduced by Ag and Mn co-doping. The experimental results show that Ag and Mn incorporation can improve the properties of Cu2ZnSnS4thin film.Keywords:Cu2ZnSnS4;Ag and Mn co-doping;thin films;sol–gel preparation
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