CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Feng Xiaoxin,Zhou Tingting,Liu Zhigang,Yang Lirong,Wang Chunmei,Xie Yuantao,Li Qinglong
Iron oxide red (IOR) is a kind of byproduct from spray pyrolysis treatment process of pickling waste liquid. In this project, manganese oxide and manganese cerium co-oxide were loaded onto the surface of IORto prepare IOR supported manganese oxide (Mn x /IOR) and IOR supported manganese-cerium co-oxide (Mnx-Cey/IOR) catalysts by a simple combustion method. Low temperature NH3-selective catalytic reduction (NH3-SCR) denitrification properties of the synthetic catalysts were studied. XRD , SEM, EDS , TEM, BET, XPS, H 2 -TPR and NH 3 -TPD were used to characterize the physiochemical properties of the catalysts. The results show that during the combustion process for preparing Mnx/IOR catalyst, MnO x , almost all in amorphous phase, can be well distributed on the surface of the IOR carrier. The NO x conversions of Mn x /IOR catalyst gradually increase with the increase of MnO x loading amount within a specific working temperature range (<200 °C). When MnO x loading amount x is 0.43, the NO x conversion is up to 85% at most. The low temperature NH 3 -SCR activity of Mn x /IOR catalyst can be enhanced remarkably by introducing cerium . The NO x conversions of Mn 0.43 -Ce y /IOR catalyst at the operating temperature range (<200 °C) increase steadily with the cerium adding amount increasing. All the Mn 0.43 -Ce y /IOR catalysts show excellent denitrification efficiency (more than 90%) at about 160 °C. Compared with Mn 0.43 /IOR catalyst, Mn 0.43 -Ce 0.1 /IOR shows excellent denitrification performance and application prospect because of its higher manganese valence state, enhanced redox capacity, larger specific surface area, and significantly improved surface acidity and anti-SO 2 poisoning ability.
研究领域:
环境科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2019
·
IF 3.355
Lijun Zhu,Hao Cheng,Jianfeng Ma,Yong Kong,Yong Qin,Sridhar Komarneni
Decolorization of methyl orange (MO) by MnO 2 was investigated with and without small molecules of organic acids such as formic acid. It was found that the decolorization could be significantly improved by MnO 2 with the assistance of organic acids. The effect of various conditions was investigated on MO decolorization by using different crystal types of MnO 2 and changing the types of organic acids. One of the optimum treatment conditions was δ-MnO 2 /formic acid system, which led to the removal efficiency of 90.6% at 30 min. The pseudo-second-order kinetic rate constant of δ-MnO 2 /formic acid was 0.1626. A reasonable decolorization mechanism involving Mn(III) species was proposed and the mechanism was validated by simple detection of ionic species such as, Mn(II) and Mn(III) during the reaction. The δ-MnO 2 /formic acid process designed here may lead to a new advanced oxidation technology based on the in-situ generation of active Mn(III) species and their ability for oxidation.
研究领域:
环境科学
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化学
✓ 已验证
产品关联
DOI
高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2015
·
IF 1.178
Chang-xin LI,Hong ZHONG,Shuai WANG,Jian-rong XUE,Fang-fang WU,Zhen-yu ZHANG
The extraction of manganese from low-grade manganese oxide ores using CaS derived from CaSO 4 as reductant was investigated. The effects of mass ratio of CaS to ore, reduction temperature, reduction time, liquid to solid ratio (L/S ratio), stirring speed, leaching temperature, leaching time and H 2 SO 4 concentration on the leaching rates of Mn and Fe during the reduction–acid leaching process were discussed. The leaching rates of 96.47% for Mn and 19.24% for Fe were obtained under the optimized conditions of mass ratio of CaS to manganese oxide ore 1:6.7, L/S ratio 5:1, stirring speed 300 r/min, reduction temperature of 95 °C for 2.0 h in the reduction process and leaching stirring speed of 200 r/min, H 2 SO 4 concentration of 1.5 mol/L, leaching temperature of 80 °C for 5 min in the leaching process. In addition, this process can be employed in the recovery of manganese from various manganese oxide ores, and Mn leaching rate above 95% is obtained.
研究领域:
冶金工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 6
·1431
·
IF 3.1
Bao Mi,Hui Zhao,Meng Lu,Yi Zhou,Yongjie Xue
The massive stockpiling of electrolytic manganese residue (EMR) has caused serious environmental pollution. In this study, EMR, coal gangue (CG), and fly ash (FA) were used as raw materials to obtain the optimal mix ratio based on Design-Expert mixture design. The effects of activator modulus, liquid–solid (L/S) ratio, and curing temperature on the mechanical properties of geopolymers were investigated. The results showed that the compressive strength of the prepared geopolymer was 12.0 MPa, and the 28d leaching of Mn was 0.123 mg/L under the conditions of EMR:CG:FA = 0.43:0.34:0.23, L/S = 0.9, a curing temperature of 60 °C, and a curing time of 24 h. This indicates that the geopolymer is an environmentally friendly material with high compressive strength. The mineral composition of the geopolymer is mainly hydrated calcium silicate and geopolymer gel. In addition, a more stable new mineral phase, MnSiO3, was generated. The Fourier transform infrared (FTIR) spectrogram showed that the peak at 1100 m−1was shifted to 1112 cm−1, which indicated that a geopolymerization reaction had occurred. Through scanning electron microscopy (SEM) and energy dispersive spectrum (EDS) analysis, it was identified that the geopolymerization produced a large amount of amorphous gelatinous substances with a relatively dense structure, the major elements being oxygen, silicon, aluminum, calcium, and sodium.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Jiaqi Li,Yuxi Zhang,Hanhao Liang,Jiaming Li,Xiao Yu,Jianglin Wang,Yini Long,Zhanhong Yang
Manganese oxide is a promising cathode material for rechargeable batteries due to its high theoretical specific capacity. However, its practical application is hindered by its poor conductivity and rapid capacity decay caused by Jahn-Teller distortion during charging and discharging. This work introduces Na 2 EDTA during the synthesis of Mn O 2 , and the amino group is introduced by adsorption to deposit to form N-doped Mn O 2 . Alkaline N-doped Mn O 2 battery upshifts the d-band center of Mn, improves the conductivity of Mn O 2 and the formation energy of O vacancies during the charge-discharge process, and suppresses Jahn Teller distortion. As a result, N-doped Mn O 2 achieves a high capacity of up to 197mAh g −1 and excellent capacity retention of 94.2% over 250 cycles with slower voltage decay. This strategy enables the material with high cycling performance for single-electron discharge secondary alkaline manganese batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Jianwang Wu,Mei Lin,Ming Liu,Zuliang Chen
Hydrogen peroxide (H 2 O 2 ) is a crucial eco-friendly oxidizer with increasing demand due to its wide range of applications. Activating O 2 with catalysts to generate H 2 O 2 on-site offers a promising alternative to traditional production methods. Here, we design unique crystalline/amorphous heterophase Fe-Mn core–shell chains (ZVI-Mn) for efficient on-site generation of H 2 O 2 and manipulation of subsequent H 2 O 2 activation. The yield of H 2 O 2 on-site produced by ZVI-Mn in water within 5 min was 103.7 mg·L -1 , which was much greater than that of zero-valent iron (ZVI) and amorphous Mn (A-Mn) (0 and 42.5 mg·L -1 ). Raman and density functional theory (DFT) calculations confirmed that *OOH is the key species involved in the on-site generation of H 2 O 2 . Electrochemical tests confirmed the excellent electron-transferring ability, while electron paramagnetic resonance (EPR) revealed oxygen vacancy defects in the catalysts, which proved to be conducive to improving the catalytic activity of ZVI-Mn. Additionally, by regulating the pH of aqueous solution , ZVI-Mn can simultaneously achieve efficient on-site generation of H 2 O 2 and in-situ removal of enrofloxacin from aqueous solution.
研究领域:
环境科学
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催化化学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2021
·Vol. 31
·期 27
·2101579
·
IF 18.808
Xiaofan Shen,Xiaona Wang,Yurong Zhou,Yanhong Shi,Liming Zhao,Hehua Jin,Jiangtao Di,Qingwen Li
Rechargeable Zn-MnO 2 batteries are boosted by the reversible intercalation reactions in mild aqueous electrolytes, but they still suffer from cathode degradation. Herein, Zn-MnO 2 batteries with high durability and high energy density are achieved by supplementing MnO 2 deposition and dissolution in a mild aqueous electrolyte. The main finding is that adjusting Mn 2+ concentration to a critical range enables a reversible MnO 2 /Mn 2+ redox conversion without the involvement of oxygen evolution. This can recycle the by-products from MnOOH disproportionation (MnOOH → MnO 2 + Mn 2+ ), resulting in a battery with extremely high durability (16 000 cycles without obvious capacity fading), high energy density (602 Wh kg −1 based on the active mass of the cathode), and high-rate capacity (430 mAh g −1 at 19.5 A g −1 ). The utilization of a 3D carbon nanotube foam skeleton can accommodate the volume change during MnO 2 deposition/dissolution and provide paths for efficient charge and mass transport. This work provides a feasible way to push the development of Zn-MnO 2 batteries in mild aqueous electrolytes.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
GEOCHIMICA ET COSMOCHIMICA ACTA
·
2021
·
IF 5.01
Jing Liu,Sayako Inoué,Runliang Zhu,Hongping He,Michael F. Hochella
It is recognized that different facets of minerals vary distinctively in their chemical reactivity with aqueous solutions. However, detailed molecular and atomistic understandings of these phenomena are relatively limited. This study investigated the interaction of aqueous Mn 2+ and dissolved oxygen on various facets of two morphology-types of iron oxide (hematite) nanocrystals. These interactions result in the oxidation of Mn(II) and heterogeneous growth of Mn(II)/Mn(III) and Mn(III) oxides. The nanoscale morphology and atomic structure of the manganese oxide products were characterized in detail. Our results, for the first time, directly demonstrate the facet-specific oxidation of Mn(II) and nucleation of Mn(II/III) oxides, followed by their epitaxial growth on hematite. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electron diffraction measurements reveal the growth of MnO x nanowires on {1 1 3} of hematite nanoplates (HNP) and {0 1 2} facets of hematite nanocubes (HNC), while the basal {0 0 1} facets on the HNP particles do not produce precipitates. The average oxidation states of the MnO x on HNP and HNC determined using electron energy-loss spectroscopy (EELS) show that both Mn(II) and Mn(III) are present. The mineral composition and growth mechanisms of MnO x catalyzed by HNP and HNC are similar. High-resolution TEM analysis reveals the presence of both hausmannite and manganite on HNP and HNC. The crystallographic relationship between the heterogeneously formed manganite with hematite, which has not been reported before, proves that hematite provides reaction sites and can function as an atomic template for the formation of MnO x nanowires. These findings advance our understanding of the redox chemistry and heterogeneous growth of minerals as controlled by the surficial structure of the substrate mineral. This has important geochemical implications as the catalytic growth of less common, highly reactive phases like MnO x are known to be consequential in complex natural and anthropogenic environments.
研究领域:
矿物学
·
地球化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2019
·
IF 1.911
Dong Sun,Guangzhi Xin,Lu Yao,Lin Yang,Xia Jiang,Wenju Jiang
Manganese leaching during high concentration flue gas desulfurization process with semi-oxidized manganese ore was studied in this paper. It was found that there were different reaction pathways among which MnO 2, Mn 2 O 3 and MnCO 3 in semi-oxidized manganese ore during flue gas desulphurization and manganese leaching. High SO 2 concentration facilitated redox reaction between MnO 2 and SO 2 , and high concentration of H 2 SO 4 accelerated MnCO 3 /Mn 2 O 3 leaching from semi-oxidized ore. Kinetics study showed that manganese leaching in flue gas desulfurization process with semi-oxidized ore was controlled by a mixed-control model, that is the surface chemical reaction and mass diffusion dominated both the oxidation of SO 2 and manganese leaching process. The apparent activation energy was 13.05 kJ·mol −1 and the reaction orders with respect to SO 2 and H 2 SO 4 concentration were 1.38 and 0.10, respectively. Finally, a semi-empirical rate equation based on shrinking core model was derived to describe the process.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Surfaces and Interfaces
·
2025
·
IF 6.3
Jun Hua,Xianwen Wu,Fangxi Xie,Mingmei Wu
Manganese-based aqueous zinc-ion batteries are considered to be one of the most promising candidates owing to its abundant resources, environmental friendliness and high safety. However, some severe problems associated with cathode are mainly plagued by Mn (III) disproportionation and Jahn-Teller distortion, leading to undesired manganese dissolution and reduced their cycle life. Herein, Cr-doped δ-MnO 2 is synthesized by a simple hydrothermal method. This study demonstrates how Cr-doping addresses these challenges by narrowing the lattice spacing between MnO 2 layers, promoting self-confinement, and mitigating Mn 2+ dissolution. As a result, Cr-doped δ-MnO 2 exhibits enhanced crystal structure stability, with superior capacity retention of 65.80 % compared to 51.53 % for pristine δ-MnO 2 after 300 cycles at 500 mA/g. Our findings provide an alternative avenue for mitigating Mn dissolution, laying the groundwork for the adoption of Zn/MnO 2 batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Qian Liu,Liying Wang,Guohua Chen,Gaoqi Wu,Jingjing Wang,Zhiwei Liu,Zhenzhu Cao,Yongfeng Zhang
Transition metal sulphides and oxides have been identified as potential cathode materials for lithium-ion batteries with high initial capacity and high selectivity. Nevertheless, the low ground conductivity and volume expansion have constituted significant obstacles to the advancement of this field of study. In this study, the heterostructure CoMn₂O₄/MnS₂@C1-2-2 of MnS₂ and CoMn₂O₄ was obtained through high-temperature (Ar. 450 °C) calcination of a novel red single crystal [CoMn(TDC)] n precursor. The resulting structure exhibited excellent lithium-ion transport properties. The biphasic heterostructure with a porous carbon framework is capable of forming a multitude of phase interfaces and conductive pathways, which facilitate charge migration, enhance conductivity, and expand the contact area with the electrolyte, thereby augmenting the charge transfer capability. The CoMn 2 O 4 MnS 2 @C1-2-2 composite displays remarkable lithium storage capabilities, with a specific capacity of 689 mA h g −1 even after 400 cycles at 0.5 A g −1 .
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
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Guocan Zheng,Yingchun Zhang,Qinrui Du,Yingxia Zhang,Kehao Wang,Jingxiao Du
Electrolytic manganese residue (EMR) represents a solid waste generated during the production of electrolytic manganese. Under the leaching and dissolution by rainwater, manganese, ammonia nitrogen, and heavy metal ions in EMR can infiltrate into the surrounding environment, thereby disrupting ecological balance and posing threats to human health. This study optimized the leaching conditions for manganese from EMR using ammonium persulfate(APS) through single-factor and orthogonal experiments. It was found that temperature, APS concentration, and reaction time significantly influenced the manganese leaching efficiency. Under leaching temperature of 80°C, leaching time of 3 hours, APS concentration of 30 g/L, and a liquid-to-solid mass ratio of 6 mL/g, a high manganese leaching rate of 88.91 % was achieved in a single process, and significant removal of ammonia nitrogen was observed. After enhanced leaching, the content of organic matter and the total amount of water-soluble salt were 4.10 wt% and 3.11 wt%, respectively. And it meets the requirements of the standard GB 18599–2020 for solid waste entering the class II site in China. Kinetic analysis revealed that the manganese leaching process was controlled by intraparticle diffusion within the solid phase. Mineralogical phase analysis indicated that the primary mineral structures were oxidatively decoupled and disrupted, leading to the dissociation of aggregates, which facilitated the leaching of manganese and ammonia nitrogen. This study provides a practical, green, and economical technological route for the harmless treatment of EMR.
研究领域:
环境科学
·
化学工程
✓ 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）