APPLIED CATALYSIS B-ENVIRONMENTAL
·
2023
·
IF 22.1
Wang Song,Qianni Cheng,Li Han,Jiawei Ji,Yandi Cai,Wei Tan,Jingfang Sun,Changjin Tang,Lin Dong
Manganese oxide-based catalysts exhibit excellent low-temperature denitration efficiency, making them potential candidates for application. Herein, the relationship between reaction stability and phase structure for MnO 2 , Mn 2 O 3 and Mn 3 O 4 was disclosed. The NO conversion for Mn 2 O 3 drastically reduced after 120 h reaction, while minor decline was detected for MnO 2 and Mn 3 O 4 . Based on dedicate qualitative and quantitative analyses on the deposits over catalyst surface, deactivation trigged by ammonium nitrate (AN) deposition was confirmed. Different from penta-coordinated Mn 4+ on MnO 2 (110) and tri-coordinated Mn 2+ , penta-coordinated Mn 4+ on Mn 3 O 4 (101), the unique tetra-coordinated Mn 3+ on Mn 2 O 3 (200) could stabilize the nitrates and make it difficult to be removed via decomposition or reaction and accumulate continuously, which resulted in the significant deactivation. This research could not only unveil the poisoning mechanism of MnO x based catalysts, but also provide new insights into the relationship between the catalytic stability and surface Mn-O microstructure.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
HYDROMETALLURGY
·
2020
·
IF 3.338
Lu Yao,Guangzhi Xin,Pengyan Pu,Lin Yang,Xia Jiang,Zhicheng Jiang,Wenju Jiang
In this work, Mn ore was mixed with the wastewater anode solution of electrolytic Mn (ASEM, instead of water) and utilized as the desulfurizer for simultaneous SO 2 removal from flue gas and Mn extraction. The effects of Fe 2+ and Fe 3+ on Mn leaching and flue gas desulfurization were investigated. For MnO 2 and Mn 2 O 3 (mixed with ASEM), the introduction of Fe 2+ could simultaneously increase Mn extraction efficiency and flue gas desulfurization efficiency when MnO 2 and Mn 2 O 3 mixed with ASEM was used. Fe 3+ addition could improve desulfurization efficiency obviously for MnCO 3 . Fe 2+ could react with MnO 2 and H + to form Mn 2+ and Fe 3+ . This reaction further improved Mn extraction and simultaneously decreased the acidity of ASEM, thus promoting SO 2 removal. The introduced Fe 3+ could react with SO 2 , when MnO 2 was absent from the desulfurizer slurry. The resulting Fe 2+ was then oxidized by O 2 to form Fe 3+ , which underwent a Fe 3+ ↔ Fe 2+ cycle to promote flue gas desulfurization. Thus, the introduction of Fe ions, especially Fe 2+ , could promote simultaneous Mn leaching and flue gas desulfurization with Mn ore. This work provided not only a new way for effective SO 2 removal from flue gas and Mn extraction but also for recycling ASEM.
研究领域:
环境科学
·
冶金工程
✓ 已验证
DOI
高影响因子
SOLID STATE SCIENCES
·
2022
·
IF 3.752
Yuncheng Zhou,Qiuyu Cheng,Bin Li,Peng Jiang,Wenbin Cao,M.A. Subramanian
A new solid solution based on general formula Ba 4 In 2- x Mn x O 7+ y (0 ≤ x ≤ 0.2) has been successfully synthesized by the sol-gel method. The compounds exhibited grass green to olive colors. The origin of the color apparently due to the presence of Mn 4+ as a chromophore in square pyramidal coordination. The X-ray diffraction results showed that the space group of all samples is I 4/ mmm . The oxidation state of Mn ion is confirmed to be +4 from the results of magnetization measurements and X-ray photoelectronic spectra (XPS). The color of Ba 4 In 2 O 7 is white. With a small amount of Mn substitution, the color of Ba 4 In 2- x Mn x O 7+ y solid solution changes to grass green, and it turned to olive green when x = 0.2. The UV–Vis absorbance spectra revealed that the absorption peaks are fitted with d 3 (Mn 4+ ) configuration in the square pyramid, and the mechanism of color is explained.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Guiyuan Cai,Yu Tian,Lipin Li,Wenxuan Zhang,Rui Huang,Jun Zhang,Qinyu Wang,Hua Xu,Yifeng Zhang
The activation of sulfite [S(IV)] by transition metals, a new generation of advanced oxidation processes, has been widely studied for water purification. However, the application of this process to oxidize and remove arsenite [As(III)] from water through Fe-based S(IV) activation and the associated mechanisms are not fully understood. In particular, rapid removal of As(III) and secondary metal contamination have presented challenges. Herein, we develop a novel sea urchin-like magnetic Fe-Mn bimetallic oxides (FeMnO)-activated S(IV) process to address these issues. Under neutral pH, the FeMnO/S(IV) system achieved a 99.2 % removal of As(III) within only 10 min with residual arsenic concentration below 10 µg/L, and the removed As(III) was fully oxidized to arsenate [As(V)]. Additionally, FeMnO was recyclable and capable of treating actual arsenic-contaminated water. Furthermore, the oxidation mechanism of non-radical active trivalent manganese [Mn(III)] was discovered during the reaction between the FeMnO/S(IV) system and As(III). The FeMnO catalyst activated S(IV) to generate oxysulfur radicals (i.e., SO 5 •– , SO 4 •– and SO 3 •– ), but they were not the primary oxidizing species for As(III). Instead, As(III) oxidation was mainly attributed to the active Mn(III) generated by the electron transfer between the FeMnO catalyst and SO 5 •– radicals. The discovery of active Mn(III) species in this work may provide a new avenue for developing novel Fe-Mn-type adsorbents to purify arsenic-contaminated water.
研究领域:
环境科学
·
水处理技术
·
化学工程
✓ 已验证
DOI
高影响因子
Nuclear Science and Techniques
·
2025
·Vol. 36
·期 5
·1-13
·
IF 3.8
Dai Zhong-Qin,Chen Huan,Wen Zhao-Yin
Lithium- and manganese-rich (LMR) oxide cathode materials are among the most attractive candidates for next-generation energy-storage materials owing to their anomalous capacity. However, severe Mn dissolution that occurs during long-term cycling, which leads to capacity loss, hinders their application prospects. In this study, nanoscale \(\textrm{AlPO}_{4}\) -coated \(\textrm{Li}_{1.2}\textrm{Ni}_{0.13}\textrm{Co}_{0.13}\textrm{Mn}_{0.54}\textrm{O}_{2}\) (LMR@APO) with significantly enhanced electrochemical performance is successfully synthesized using a simple and effective sol–gel method to mitigate Mn dissolution and suppress local structural distortion at high voltages. Because of the complex evolution of the structure and oxidation state of LMR materials during electrochemical cycling, observing and analyzing them using traditional single characterization methods may be difficult. Therefore, we combine various synchrotron-based characterization techniques to conduct a detailed analysis of the electronic and coordination structures of the cathode material from the surface to the bulk. Synchrotron-based hard and soft X-ray spectroscopies are integrated to investigate the differences in O and Mn evolution between the surfaces and bulk of the cathode. Advanced synchrotron-based transmission X-ray microscopy combined with X-ray near-edge absorption-structure technology is utilized to visualize the two-dimensional nanometer-scale reactivity of the LMR cathode. The \(\textrm{AlPO}_{4}\) -coating layer can stabilize the surface structure of the LMR material, effectively alleviating irreversible oxygen release on the surface and preventing the dissolution of \(\textrm{Mn}^{2+}\) at the interface caused by side reactions after a long cycle. Therefore, the spatial reaction uniformity of Mn is enhanced by the \(\textrm{AlPO}_{4}\) -coating layer, and rapid capacity decay caused by Mn deactivation is prevented. The \(\textrm{AlPO}_{4}\) -coating method is a facile modification strategy for high-performance LMR materials.
研究领域:
材料科学
·
能源存储技术
·
表面科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2025
·
IF 11.3
Wen Qin,Chengyuan Zheng,Haoming Qin,Yang Song,Yang Zhou,Jin Jiang,Jun Ma
Permanganate/electron shuttle systems for the enhanced transformation of anilines were evaluated. The presence of electron shuttles (2,2’-azino-bis(3-ethylbenzothiazoline)-6-sulfonate (ABTS), 1-hydroxybenzotriazole (HBT) and catechol (CAT) accelerated the oxidative transformation of aniline by Mn(VII). In the Mn(VII)/ABTS process, ABTS •+ was partially consumed through fragmentation or polymerization with aniline, while the second-order rate constants ( k app 2 , M −1 s −1 ) of the interaction of ABTS •+ with aniline rose from 86.57 to 140.04 M −1 s −1 with increase in pH from 5 to 8. In the Mn(VII)/HBT system, aniline removal was markedly enhanced under acidic conditions due to the formation of polymerized products via radical cations (HBT • ). Furthermore, the oxidative transformation of aniline (82.5 %) by Mn(VII)/CAT was significantly higher than that by Mn(VII) (65.2 %) because of Michael addition reaction of aniline and ortho-benzoquinone (o-BQ). Moreover, the formation of Mn(III) was confirmed by the overall oxidation state (3.13) and the X-ray Photoelectron Spectroscopy (XPS) spectra of the Mn products in the CAT/Mn(VII) process, revealing a synergistic mechanism between o-BQ and Mn(III) for enhanced aniline degradation.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Yangyang Yang,Panpan Zhang,Kunsheng Hu,Xiaoguang Duan,Yongxiang Ren,Hongqi Sun,Shaobin Wang
Manganese oxides have been applied in advanced oxidation processes (AOPs), however, underlying oxidation regimes are still debatable. In this work, we synthesized various crystalline manganese oxides and single or dual metal-doped amorphous MnO 2 (M-AMO, M = Fe, Co, Ni, and Cu) for organic oxidation with peroxymonosulfate (PMS). M-AMO at 1 mol% exhibited much higher activities than crystalline manganese oxides and Cu-AMO displayed the rate constant at 3.5 times as high as that of AMO. Different from conventional radical oxidation, nonradical degradation occurred via two pathways. Cu-doping resulted in relatively higher-crystallized structure, more oxygen vacancies, and a higher ratio of Mn 4+ /Mn 3+ for a faster redox cycle between Mn Ⅳ (s) and Mn Ⅲ (s) to boost PMS activation and direct/indirect (Cu-AMO–PMS complex-based) phenol oxidation. This study contributes to a new insight to the structure-catalysis relationship in manganese-catalyzed PMS oxidation. The outcomes will direct the rational synthesis of reaction-oriented catalysts for nonradical AOPs and novel remediation technologies.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
MATERIALS LETTERS
·
2023
·
IF 3
Siqi Li,Yanan Wei,Qiong Wu,Yuan Han,Rongmei Liu,Guixiang Qian,Chao Yang
The spiny spherical MnCO 3 @MnO 2 cathode material for aqueous zinc ion batteries was designed and constructed. Electrochemical test results revealed that, the spiny spherical MnCO 3 @MnO 2 cathode material had an initial discharge capacity of 598.2 mAh/g at a current density of 0.2 A/g. As the current density increased with the gradient and then decreased to 0.2 A/g, the specific capacity remained at 541.5 mAh/g, indicating the superior performances compared to that of MnCO 3 . This research showed that this spiny spherical MnCO 3 @MnO 2 has distinctive structural characteristics and can easily embed zinc ions, demonstrating a competitive cycle stability in aqueous systems.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
Science China-Chemistry
·
2024
·
IF 10.4
Liu Zheng,Qiu Zhipeng,Li Zhiyuan,Wei Tong,Fan Zhuangjun,Pang Huan
Due to the low cost, high theoretical capacity, and environmental friendliness, manganese-based cathodes are regarded as promising alternatives for aqueous zinc ion batteries (AZIBs). However, the practicality of the zinc-manganese system is faced with great challenges, such as the inevitable structural collapse of the cathode and controversial energy storage mechanisms. Herein, we propose a novel concept of spatial deposition mechanism through the addition of MnSO 4 additives in the MnO-pillared graphene blocks (G-MnO). The covalent interface between MnO nanoparticles and multilayered graphene nanosheets can construct an in-built micro-electric field, which is beneficial for consecutive electron transfer (in both horizontal and vertical directions). On this basis, the surficial activity of MnO confined in the interlayered nano-space is greatly enhanced and provides enough spatial deposition and subsequent reaction site for MnSO 4 additives, thus firstly extending the surficial controlled process to stereoscopic space, effectively improving the electrochemical performance of AZIBs. Therefore, the assembled Zn//G-MnO battery exhibits an excellent rate capability of 281.5 mAh g −1 at 0.1 A g −1 and 106 mAh g −1 at 20 A g −1 , and impressive cycling stability (93 mAh g −1 remaining after 5,000 cycles). This finding may provide a new opportunity for the rational design of surficial controlled energy storage and conversion devices.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Xiaorui Sun,Ruijuan Xiao,Xiqian Yu,Hong Li
Mn dissolution is one of the most important factors for the failure of LiMn2O4 batteries. Doping has been widely adopted in the modification of LiMn2O4 cathodes; however, there is still a lack of theoretical guidance on screening the dopants. Here, through first-principles calculations, we systematically investigated the effects of all 3, 4d transition metals as well as Mg, Ca, Sr, Al, Ga, and In on the surface oxygen stability of LiMn2O4 cathodes, which has been proved to be correlated with the stability of the surface Mn atoms. Six competitive dopants, namely Nb, Ru, Mo, V, Tc, and Ti, were screened out. Besides, for three dopants in low valence states (Mg, Cu, and Zn), their Li-site doping can more effectively stabilize the surface oxygen atoms compared with Mn-site doping. Finally, we synthesized LiMn2O4 samples with Mg, Mo, and Nb surface doping to validate the rationality of the computational results. We found that particle morphology should also be considered in addition to surface oxygen stability for controlling Mn dissolution. Moreover, the electrochemical performance of LiMn2O4 batteries is a more complex issue and cannot be solely regulated by Mn dissolution. During the experiments, we have explored novel efficient binary chromogenic reagents for ultraviolet–visible spectroscopy analysis that can be used for rapid and low-cost Mn dissolution detection. This work provides a paradigm for the systematic design of the surface modification of the LiMn2O4 cathode under theoretical guidance.
研究领域:
材料科学
·
理论计算
·
电池技术
✓ 已验证
DOI
PubMed
高影响因子
Materials Today Chemistry
·
2024
·
IF 6.7
Minghui Lu,Xiaodong Shen,Bao Ke,Tao Huang,Ou Xu,Linghang Kong,Xianci Zhong,Bingsuo Zou
Manganese halides , as dilute magnetic semiconductor materials , have magnetic coupling interactions that play an essential role in their photoluminescence (PL); however, such interactions remain controversial. A MnCl 3 ( A MC, A = K, Rb, and Cs) and their hydrates A MnCl 3 ·2H 2 O ( A MCH, A = K, Rb, and Cs) are both in the ABX 3 configuration but exhibit a wide variety of structures with different connectivity types and dimensions. Their magnetic coupling interaction has been demonstrated. However, few studies have systematically investigated the PL in conjunction with the magnetic coupling interaction over these chloride compounds. In this paper, the effect of the magnetic coupling interaction on A MC and A MCH PL is mainly revealed by temperature-dependent PL spectra and lifetimes. The Mn X 6 ( X 6 = Cl 4 (H 2 O) 2 or Cl 6 ) cluster connection types affect the Mn 2+ –Mn 2+ distances. The magnetic coupling interaction between Mn X 6 octahedrons affects the radiative transitions of manganese chlorides, which is influenced by the Mn 2+ –Mn 2+ distance, local symmetry, and water ligand. The Mn 2+ –Mn 2+ distance and the magnetic coupling interaction also affect their lifetimes. Variations in magnetic coupling interactions can shift emission wavelength , especially dual-emissions and near-infrared (NIR) emission at lower temperatures while A + = K + . This work helps researchers understand the optical process of Mn 2+ ions in different manganese compounds and provides new insights into the design of tailored Mn 2+ ion phosphors.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE SCIENCES
·
2016
·
IF 2.041
Peng Jiang,Ting Xiao,Yuncheng Zhou,Jianlei Kuang,Qi Wang,Wenbin Cao
Brownmillerite-type oxides Ba 2 In 2-x Mn x O 5+x ( 0 ≤ x ≤ 0.6 ) samples showing intense turquoise to green color were synthesized through a novel microwave assisted rapid sintering method. The properties of as-synthesized samples were compared with samples prepared by previously reported solid state reaction by X-ray diffraction, scanning electronic microscopy, UV-visible absorbance spectra and X-ray photoelectron spectroscopy. The X-ray diffraction patterns showed that the structure symmetry converts from orthorhombic to cubic with the increase in Mn content. And UV-visible absorbance spectra revealed that the color is tuned from turquoise to green color by manganese doping. In the as-synthesized samples, manganese is showing Mn 5+ according to the X-ray photoelectron spectroscopy results.
研究领域:
材料科学
·
无机化学
✓ 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）