Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 43
·22763-22772
·
IF 11.301
Jiaxi Xue,Yajing Wang,Cui Sun,Pan Xu,Xiaoxiang Fan,Jingmin Fan,Mingsen Zheng,Quanfeng Dong
Li-rich Mn-based materials, as high-energy-density and low-cost cathode materials for Li-ion batteries, suffer severe irreversible voltage fading and capacity loss during cycling, associated with the instability of crystal structure at high voltage, which greatly reduces the specific energy density after cycling and thus impedes their commercialization. Here, we introduce a new strategy to mitigate voltage fading and improve the cycling performance of Li-rich Mn-based cathode materials by simply introducing MgSO4 in the cathode during its preparation process. The results show that cycling stability and voltage fading of corresponding batteries were dramatically improved due to the high Li+ retention at the initial charge process and the stable cathode electrolyte interface (CEI) layer. After 100 cycles at 1C, the average discharge voltage decay is only 0.115 V (1.15 mV per cycle), with a high voltage retention of 96.7%, and the capacity remains at 91.5% after 300 cycles at 1C.
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CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Fawen Liang,Zhang Liu,Xueding Jiang,Jiesen Li,Kaibang Xiao,Weicheng Xu,Xin Chen,Jinzhi Liang,Zhifeng Lin,Meng Li,Xiaolian Wu,Hailong Wang
In this study, NaOH-modified biochar supported Fe/Mn bimetallic composite (Fe-Mn/AW-BC) was prepared to remove tetracycline (TC) through activating peroxymonosulfate (PMS). Results showed that about 97.9 % of TC was degraded and the rate constant of Fe-Mn/AW-BC + PMS system was 37 folds higher than BC + PMS system. Experimental results confirmed that both radical and non-radical pathway were contribute to the catalytic system. Density functional theory (DFT) results also suggested that Fe-Mn/AW-BC sample was favorable for adsorbing PMS based on the length O O bond from PMS and the E ads of catalysts. The superior activation ability was ascribed to the accelerating formation of reaction active species and other oxidation species by bimetallic structures of Fe-Mn and oxygenated functional groups of BC. Additionally, the redox cycles of Fe 3+ /Fe 2+ and Mn 3+ /Mn 2+ under Fe-Mn-BC synergism promoted the generation of the radicals, whereas the carbon shell effectively inhibited metals leaching of Fe-Mn/AW-BC, and 77.8 % of TC can be still removed within 60 min after five consecutive cycles. Notably, Fe-Mn/AW-BC system has special characteristic of wide pH usable range and broad-spectrum adaptability towards various organic pollutants and various water environments. Based on intermediate identification and Fukui function calculation, the degradation pathways of TC were also proposed. This study highlights the applications of biochar for the environmental catalysis.
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CANADIAN JOURNAL OF CHEMICAL ENGINEERING
·
2023
·Vol. 101
·期 12
·6807-6816
·
IF 2.1
Renjie Deng,Wenjin Ni,Yao Tian
Bimetallic cerium-manganese modified Hβ zeolite sample (Ce/Mn-Hβ) was prepared by ultrasonic assisted impregnation method and applied in nitration of toluene. The characterization results show that the active components (Ce and Mn) are successfully introduced into the framework of Hβ zeolite. The catalyst shows excellent catalytic activity and reusability for the nitration of toluene, giving high para selectivity. Under optimized conditions, it gives 68.7% selectivity to para -nitrotoluene at 88.6% conversion over Ce/Mn-Hβ in the presence of acetic anhydride (Ac 2 O). The theoretical calculations indicate that the Ce/Mn bimetallic active sites in modified Hβ zeolite can easily activate the nitrification reagent (AcONO 2 ), and the enhancement of para selectivity is owing to the steric hindrance of catalyst. Furthermore, the reaction mechanism was proposed by the combination of experimental results and theoretical calculations.
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Materials
·
2021
·Vol. 14
·期 20
·5958
·
IF 3.623
Xusheng Ren,Zhiliang Ou,Bang Wu
The activated coke is a promising support for catalysts, and it is important to study the performance of the activated coke catalyst on the removal of NOx. In the current research, a series of the activated coke-supported Mn–Cu catalysts are prepared by the incipient wetness impregnation method. The effects of the molar ration of Mn/Cu, the content of Mn–Cu, the calcination temperature, and reaction space velocity on NO conversion are investigated, and it was found that the 8 wt.% Mn0.7Cu0.3/AC had the best catalytic activity when the calcination temperature was 200 °C. The existence of SO2caused the catalyst to deactivate, but the activity of the poisoning catalyst could be recovered by different regeneration methods. To uncover the underlying mechanism, BET, XPS, XRD, SEM and FTIR characterizations were performed. These results suggested that the specific surface area and total pore volume of the poisoning catalyst are recovered and the sulfite and sulfate on the surface of the poisoning catalysts are removed after water washing regeneration. More importantly, the water washing regeneration returns the value of Mn3+/Mn4+, Cu2+/Cu+, and Oα/Oβ, related to the activity, basically back to the level of the fresh catalyst. Thus, the effect of water washing regeneration is better than thermal regeneration. These results could provide some helpful information for the design and development of the SCR catalysts.Keywords:activated coke;low-temperature NH3-SCR;sulfur poisoning;regeneration
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高影响因子
MOLECULES
·
2023
·Vol. 28
·期 14
·5544
·
IF 4.6
Min Wang,Shilin Zhang,Juejin Teng,Shunsheng Zhao,Zhongtao Li,Mingbo Wu
An efficient and low-cost oxygen catalyst for the oxygen reduction reaction (ORR) was developed by in situ growth of Mn-Mo oxide nanoparticles on nitrogen-doped carbon nanotubes (NCNTs). Doped nitrogen effectively increases the electron conductivity of the MnMoO4@NCNT complex and the binding energy between the Mn-Mo oxide nanoparticles and carbon nanotubes (CNTs), leading to fast charge transfer and more catalytically active sites. Combining Mn and Mo with NCNTs improves the catalytic activity and promotes both electron and mass transfers, greatly enhancing the catalytic ability for ORR. As a result, MnMoO4@NCNT exhibited a comparable half-wave potential to commercial Pt/C and superior durability, demonstrating great potential for application in renewable energy conversion systems.Keywords:MnMoO4/NCNT composites;nitrogen doping;oxygen reduction reaction;platinum group metal (PGM)-free catalyst;electrocatalysis
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高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Zhihao Liang,Rongxia Huang,Tianbao Xie,Yi Zhang,Hua-Tay Lin,Yejing Dai
Bi 4 Ti 3- x (Mn 1/3 Ta 2/3 ) x O 12 piezoelectric ceramics were prepared by conventional sintering and direct-reaction sintering in this study. The effect of B-site Mn/Ta co-substitution and sintering method on the microstructure and electrical properties of Bi 4 Ti 3- x (Mn 1/3 Ta 2/3 ) x O 12 piezoelectric ceramics was systematically investigated. The experimental results show that the combination of high-valent Ta and low-valent Mn ions replacing Ti 4+ ions reduce the concentration of oxide vacancy defects in BITMT ceramics. The direct-reaction sintering is a simpler preparation method and the prepared samples have more uniform grain distribution and higher density. The resistivity of the direct reaction sintered sample with x = 0.05 at 500 °C is 7.19 × 10 5 Ωcm, the residual polarization is 8.1 μC/cm 2 , and the temperature stability of the piezoelectric constant is good. Therefore, the present study suggests that the piezoelectric properties of Mn and Ta co-doping of BIT ceramics could be greatly enhanced via the direct-reaction sintering, which provides a promising alternative to the conventionally sintered for a more cost-effective preparation for BIT ceramics.
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Journal of Materials Chemistry C
·
2023
·Vol. 11
·期 14
·4837-4845
·
IF 6.4
Yao Zhang,Chengpeng Hu,Yu Wang,Xiaolin Huang,Xuejie Sun,Mingxuan Liu,Bohan Xing,Xing Wen,Hao Tian
The improvement of piezoelectric properties is always a key issue in the study of piezoelectric materials. The construction of composition gradient (CG) is a novel method to improve piezoelectric properties. However, the physical mechanism of CG influence on the piezoelectric properties has to be analyzed further. We investigate the origin of the CG-affected piezoelectric property using a manganese-doped potassium sodium niobate single crystal (that is Mn: KNN) as a model system. The relationship between CG, microstructure and spontaneous polarization was explored by designing and growing Mn:KNN single crystals with different CGs. It is found that the built-in electric field (Ein) in single crystals is constructed by introducing the CG in the crystals. The large Ein induces a more ordered, large-sized striated domain structure. The Mn: KNN single crystal with a large CG has a uniform orientation of spontaneous polarization and large macro-piezoelectric properties (83 pC N−1). Therefore, it is important to explore the relationship between CG and the piezoelectric properties of single crystals in lead-free piezoelectric materials. The results can be used to further develop high-performance lead-free piezoelectric materials.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Jiangkun Du,Jianguo Bao,Ying Liu,Sang Hoon Kim,Dionysios D. Dionysiou
Metal oxides are potentially interesting catalysts for activating peroxymonosulfate (PMS) for the degradation of recalcitrant contaminants. This study presents a magnetic porous Mn-Fe binary oxide (p-Mn/Fe 3 O 4 ) in micron-size with abundant micro- and meso- pores. This novel catalyst exhibited high efficacy and long-term stability in activating PMS for degradation of bisphenol A (BPA). Sulfate radicals and hydroxyl radicals were identified from catalytic PMS activation according to electron paramagnetic resonance (EPR) characterization. The effects of Fe/Mn ratio, catalyst dose, initial pH and temperature were investigated. Compared to monometallic oxides, p-Mn/Fe 3 O 4 exhibited a better catalytic performance because of the significant synergy between Mn and Fe species. Several BPA intermediates were identified. On the basis of bio-toxicity assay and TOC measurements, BPA transformed to some toxic intermediates during the initial reaction stage, and then decomposed efficiently to low toxicity products and mineralized to carbon dioxide and water molecules. This study shows that p-Mn/Fe 3 O 4 is an efficient and environmentally benign catalyst for PMS oxidation of organic pollutants.
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高影响因子
NANOTECHNOLOGY
·
2023
·Vol. 34
·期 14
·145403
·
IF 3.5
Huiying Wang,Ziyan Kong,Minghao Wang,Bing Huang,Lunhui Guan
Manganese and nitrogen co-doped porous carbon (Mn–N–C) are proposed as one of the most up-and-coming non-precious metal electrocatalysts to substitute Pt-based in the oxygen reduction reaction (ORR). Herein, we chose metal triazole frameworks as carbon substrate with hierarchical porosity for trapping and anchoring Mn-containing gaseous species by a mild one-step pyrolysis method. The optimized Mn–N–C electrocatalyst with a large metal content of 1.71 wt% and a volume ratio of 0.86 mesopores pore delivers a superior ORR activity with a half-wave potential (E1/2) of 0.92 V in 0.1 M KOH and 0.78 V in 0.1 M HClO4. Moreover, the modified Mn–N–C catalyst showed superior potential cyclic stability. The E1/2 remained unchanged in 0.1 M KOH and only lost 6 mV in 0.1 M HClO4 after 5000 cycles. When applied as the cathode catalyst in Zn-air battery, it exhibited a maximum peak power density of 176 mW cm−2, demonstrating great potential as a usable ORR catalyst in practical devices.
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高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Chunhao Wang,Haipeng Chen,Jian Deng,Liqing Li,Zheng Zeng,Xiancheng Ma,Siyu Wei
Exploring the single relationship between the inversion degree of spinel and its catalytic performance is a great challenge, but has important significance for further structural design and application. A series of CoMn inverse spinels were prepared and the general formula Co 1 - x 2 + Co x 3+ tet Mn 1 3+ Co x 2+ Co 1 - x 3+ oct O 4 was deduced through X-ray diffraction refinement to find a decreased inversion degree x as calcination temperature rose. Catalytic oxidation of toluene showed that higher inversion degree (S-300 with x ≈ 0.95) can reach larger conversion rate (90 % at about 250 °C for 400 ppm toluene) with greater reaction stability (140 h). Density Functional Theory (DFT) calculations on density of states indicated its metallic nature, and found that the strength of O-p and Transition metal-d orbitals at Fermi energy is positively correlated to the inversion degree, meaning stronger electron migration ability. Along with the adsorption calculation analysis that lattice oxygen species are proved to work dominantly (S-300 with lowest adsorption energy but highest performance), this work uncovered a theoretical insight into inverse spinel oxide , to provide the possibility of elevated oxidation ability through structural control.
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Materials
·
2024
·Vol. 17
·期 5
·1200
·
IF 3.1
Wei Tong,Weiqiang Wang,Xiayu Leng,Jianli Song
To enhance the comprehensive performance of solid oxide fuel cells (SOFCs) ferritic stainless steel (FSS) interconnectors, a novel approach involving composite electrodeposition and thermal conversion is proposed to prepare Ni-doped Co-Mn composite spinel protective coatings on FSS surfaces. The process involves the composite electrodeposition of a Ni-doped Co-Mn precursor coating, followed by thermal conversion to obtain the Co-Mn-Ni composite spinel coating. Crofer 22H was used as the substrate and orthogonal experiments were designed to investigate the influences of deposition solution pH, stirring rate, cathode current density, and the element content of Mn and Ni on the surface morphology and properties of the composite coatings, respectively. The characterization of the prepared coatings was conducted through macroscopic and microscopic morphology observations of the component surface, energy dispersive spectroscopy (EDS) analysis, and area specific resistance (ASR) testing, etc. Finally, the optimized composite electrodeposition parameters and the Mn-Ni content ratio in the solution were obtained. Experimental results indicated that the composite spinel coating prepared with the optimized process parameters exhibited excellent adhesion to the substrate, and the diffusion and migration of Cr element has been effectively inhibited. Compared with the substrate, the ASR of the coated components has also been decreased simultaneously, which provided an effective method for the surface modification of SOFC FSS interconnectors.
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高影响因子
CHEMISTRY OF MATERIALS
·
2022
·
IF 10.508
Mao-Yin Ran,Sheng-Hua Zhou,Bingxuan Li,Wenbo Wei,Xin-Tao Wu,Hua Lin,Qi-Long Zhu
Simultaneous regulation and control of non-linear second-harmonic-generation (SHG) coefficients (deff) and linear birefringence (Δn) of non-centrosymmetric (NCS) crystals is a crucial aspect of improving the non-linear optical (NLO) performance, yet it remains a huge challenge in modern laser techniques and science. Herein, a series of melilite-type oxide-derived NCS oxychalcogenides, Sr2MGe2OS6 (M = Mn, Zn, and Cd), are successfully designed and synthesized through a facile partial isovalent chemical substitution strategy. These isostructural compounds crystallize in the tetragonal NCS space group P4̅21m (no. 113) and feature unique two-dimensional Cairo pentagonal tiling layers composed of heteroligand [GeOS3] and tetrahedral [MS4] asymmetric building units (ABUs). Compared to the parent melilite-type oxides, the derived title compounds not only successfully realize the phase matchability transformation [i.e., from non-phase-matching (NPM) to phase-matching (PM)] but also greatly improve the IR-NLO performance (especially, simultaneously boosting deff and Δn). Sr2CdGe2OS6 exhibits the best comprehensive performance among oxychalcogenides, including a wide PM cutoff edge (>525 nm), a strong deff (0.8 × AgGaS2), a giant laser-induced damage threshold (19.2 × AgGaS2), a large band gap (3.62 eV), as well as a broad transmission cutoff region (0.28–12.0 μm). Furthermore, highly distorted [GeOS3] ABU in this melilite-type structure is proved to be the profitable bifunctional NLO-active unit, which can contribute to the search and design of novel IR-NLO crystals with a large Δn and a strong deff based on the experimental results and theoretical calculations. This work demonstrates the first examples of PM melilite-type oxychalcogenides and offers new perspectives on the phase matchability transformation through the partial isovalent chemical substitution approach, which will play a constructive role in the future design of high-performance IR-NLO heteroanionic materials.
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