ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2022
·
IF 11.357
Hongchao Li,Na Yuan,Jieshu Qian,Bingcai Pan
The environmentally benign Mn oxides play a crucial role in the transformation of organic contaminants, either through catalytically decomposing oxidants, e.g., peroxymonosulfate (PMS), or through directly oxidizing the target pollutants. Because of their dual roles and the complex surface chemical reactions, the mechanism involved in Mn oxide-catalyzed PMS activation processes remains obscure. Here, we clearly elucidate the mechanism involved in the Mn2O3 catalyzed PMS activation process by means of separating the PMS activation and the pollutant oxidation process. Mn2O3 acts as a shuttle that mediates the electron transfer from organic substrates to PMS, accompanied by the redox cycle of surface Mn(IV)/Mn(III). Multiple experimental results indicate that PMS is bound to the surface of Mn2O3 to form an inner-sphere complex, which then decomposes to form long-lived surface reactive Mn(IV) species, without the generation of sulfate radicals (SO4•–) and hydroxyl radicals (HO•). The surface reactive Mn(IV) species are proposed to be responsible for the degradation of organic contaminants (e.g., phenol) and the formation of singlet oxygen (1O2), followed by the regeneration of the surface Mn(III) sites on Mn2O3. This study advances the fundamental understanding of the underlying mechanism involved in transition metal oxide-catalyzed PMS activation processes.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2020
·
IF 7.216
Min Mao,Xingxing Wu,Yi Hu,Qunhui Yuan,Yan-Bing He,Feiyu Kang
Aqueous Zinc-ion batteries (ZIB) are attracting immense attention because of their merits of excellent safety and quite cheap properties compared with lithium-ion batteries (LIB). Manganese oxide is one of the most important cathode materials of ZIB. In this paper, α-Mn 2 O 3 used as cathode of ZIB is synthesized via Metal-Organic Framework (MOF)-derived method, which delivers a high specific capacity of 225 mAh g −1 at 0.05 A g −1 and 92.7 mAh g −1 after 1700 cycles at 2 A g −1 . The charge storage mechanism of α-Mn 2 O 3 cathode is found to greatly depend on the discharge current density. At lower current density discharging, the H + and Zn 2+ are successively intercalated into the α-Mn 2 O 3 before and after the “turning point” of discharge voltage and their discharging products present obviously different morphologies changing from flower-like to large plate-like products. At a higher current density, the low-voltage plateau after the turning point disappears due to the decrease of amount of Zn 2+ intercalation and the H + intercalation is dominated in α-Mn 2 O 3 . This study provides significant understanding for future design and research of high-performance Mn-based cathodes of ZIB.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Xiao Yu,Mengyi Shi,Yixuan Fan,Lixia Yang,Jie Zhang,Wei Liu,Weili Dai,Shuqu Zhang,Lei Zhou,Xubiao Luo,Shenglian Luo
Mn 2 O 3 is an exceptional earth-abundant mineral that has been extensively applied in catalytic oxidation because of the strong redox couples like Mn 3+ /Mn 2+ and Mn 4+ /Mn 3+ exposed on Mn 2 O 3 surface. Herein, the catalytic activity of Mn 2 O 3 in photothermal degradation of toluene was regulated by halogens including F - , Cl -, and Br - . As the electronegativity ordered in F (3.98) > O (3.44) > Cl (3.16) > Br (2.96), F - doped Mn 2 O 3 overperforms Cl - doped and Br - doped Mn 2 O 3 in decomposing toluene. DFT theoretical calculation illustrates that F - attracts the shared electrons from Mn to itself, the deviated charge center stretches the adjacent Mn-O bonds and boosts the generation of abundant oxygen vacancies, helping to strengthen the catalytic activity of Mn 2 O 3 . Conversely, Mn-O bonds are shortened by Cl - and Br - that have lower electronegativity than O. The multiple electrons circling Cl - and Br - push Mn towards O and squeeze Mn-O bonds, resulting in the formation of passivated Mn 2 O 3 . In conjunction with Mn redox couples and oxygen vacancies, 99% of 400 ppm toluene can be eliminated by F - doped Mn 2 O 3 , corresponding mineralization rate is high up to 95.8%.
研究领域:
催化
·
环境科学
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Green Energy & Environment
·
2025
·
IF 14.6
Peiya Chen,Xinghao Li,Yuhan Liu,Huai Liu,Rui Zhang,Wenlong Jia,Junhua Zhang,Yong Sun,Lincai Peng
Concurrent activation of lattice oxygen (O L ) and molecular oxygen (O 2 ) is crucial for the efficient catalytic oxidation of biomass-derived molecules over metal oxides. Herein, we report that the introduction of ultralow-loading of Ru single atoms (0.42 wt%) into Mn 2 O 3 matrix (0.4%Ru-Mn 2 O 3 ) greatly boosts its catalytic activity for the aerobic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA). The FDCA productivity over the 0.4%Ru-Mn 2 O 3 (5.4 mmol FDCA ‧g cat -1 ‧h -1 ) is 4.9 times higher than the Mn 2 O 3 . Especially, this FDCA productivity is also significantly higher than that of existing Ru and Mn-based catalysts. Experimental and theoretical investigations discovered that the Ru single atom facilitated the formation of oxygen vacancy (O v ) in the catalyst, which synergistically weakened the Mn-O bond and promoted the activation of O L . The co-presence of Ru single atoms and O v also promote the adsorption and activation of both O 2 and HMF. Consequently, the dehydrogenation reaction energy barrier of the rate-determining step was reduced via both the O L and chemisorbed O 2 dehydrogenation pathways, thus boosting the catalytic oxidation reactions.
研究领域:
化学
·
催化反应
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Fen Qiao,Wenjie Liu,Shuihua Yu,Qiaoling Zhang,Guodong Li,Huaqiang Chu
Mn 2 O 3 is and has received widespread attention in fields such as catalysis and energy storage. However, its poor conductivity limits its application as an electrode material for supercapacitors. Here, flower-like spheroidal δ-MnO 2 /Mn 2 O 3 composites composed of two-dimensional (2D) hierarchical nanosheets were prepared by the template method and a simple hydrothermal process. The growth process and electrochemical properties of δ-MnO 2 /Mn 2 O 3 composites were investigated by adjusting the concentration of KMnO 4 in the hydrothermal process. Since the introduction of δ-MnO 2 brings more pseudocapacitance to the composite, the synergistic effect between MnO 2 and Mn 2 O 3 reduces the interfacial resistance, and the unique nanosheet structure increases its specific surface area, which alleviates the volume expansion during the cycling, the δ-MnO 2 /Mn 2 O 3 composite electrode exhibits high specific capacitance (182 F g −1 at 0.5 A g −1 ), fast rate performance (74.2% capacitance retention at 5 A g −1 ), and excellent cyclic stability (90.1% capacitance retention after 5000 cycles at 5 A g −1 ). Symmetric supercapacitors assembled with δ-MnO 2 /Mn 2 O 3 electrodes also exhibit a high energy density of 9.1 Wh kg −1 . δ-MnO 2 /Mn 2 O 3 composites have greater application prospects in energy storage, and are expected to achieve further applications in lithium/sodium ion batteries, zinc ion batteries and other fields.
研究领域:
材料科学
·
能源存储与转换
✓ 已验证
产品关联
DOI
高影响因子
Science Advances
·
2017
·Vol. 3
·期 6
·
IF 0
Pengwei Wang,Guofeng Zhao,Yu Wang,Yong Lu
Oxidative coupling of methane (OCM) is a promising method for the direct conversion of methane to ethene and ethane (C2 products). Among the catalysts reported previously, Mn2O3-Na2WO4/SiO2 showed the highest conversion and selectivity, but only at 800° to 900°C, which represents a substantial challenge for commercialization. We report a TiO2-doped Mn2O3-Na2WO4/SiO2 catalyst by using Ti-MWW zeolite as TiO2 dopant as well as SiO2 support, enabling OCM with 26% conversion and 76% C2-C3 selectivity at 720°C because of MnTiO3 formation. MnTiO3 triggers the low-temperature Mn2+↔Mn3+ cycle for O2 activation while working synergistically with Na2WO4 to selectively convert methane to C2-C3. We also prepared a practical Mn2O3-TiO2-Na2WO4/SiO2 catalyst in a ball mill. This catalyst can be transformed in situ into MnTiO3-Na2WO4/SiO2, yielding 22% conversion and 62% selectivity at 650°C. Our results will stimulate attempts to understand more fully the chemistry of MnTiO3-governed low-temperature activity, which might lead to commercial exploitation of a low-temperature OCM process.
研究领域:
化学工程
·
催化
·
能源化学
✓ 已验证
产品关联
DOI
PubMed
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2025
·
IF 3.7
Dingding Liu,Yating Huang,Zhenguo Li,Guohua Jing,Yongdan Li,Huawang Zhao
The advancements in engine technology have led to a decrease in exhaust temperatures, hence enhancing the activity of Cu-SSZ-13 at low temperatures becomes crucial and challenging. This enhancement can be achieved using dual-phase metal oxide/Cu-SSZ-13 composite catalysts. In this work, we evaluated the comparative efficacy of Mn 3 O 4 and Mn 2 O 3 and discovered that Mn 3 O 4 exhibited a significantly superior enhancement in deNO x activity of Cu-SSZ-13 at low temperatures, achieving 95% NO x conversion at 200 °C. This is substantially higher than the conversions recorded by Mn 2 O 3 /Cu-SSZ-13 (78%) and Cu-SSZ-13 (40%). Kinetic and IR results demonstrate that Mn 3 O 4 /Cu-SSZ-13 and Mn 2 O 3 /Cu-SSZ-13 composite samples share a same low-temperature pathway, where bridged nitrates formed on the MnO x react with adsorbed on Brønsted acid sites in Cu-SSZ-13. In this reaction pathway, bridged nitrate formation is identified as the rate-determining step. The distinctive structure of Mn 3 O 4 triggers an increase in oxygen vacancies, creating a higher content of chemically adsorbed oxygen, compared to Mn 2 O 3 . Those adsorbed oxygen facilitates bridged nitrate formation. Consequently, due to the larger amount of bridged nitrate formed on Mn 3 O 4 compared to Mn 2 O 3 , the Mn 3 O 4 /Cu-SSZ-13 sample exhibits higher activity.
研究领域:
环境催化
·
材料化学
·
大气污染控制
·
化学工程
·
表面科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Na Tian,Xike Tian,Yulun Nie,Chao Yang,Zhaoxin Zhou,Yong Li
Peroxymonosulfate (PMS) activation has drawn increasing attention in eliminating the recalcitrant organic pollutants in water. Manipulation of generated reactive oxygen species (ROS) over Ce doped Mn 2 O 3 during the PMS activation was firstly reported for the complete degradation of 2,4-dichlorophenol (2,4-DCP) in this study. Ce in-situ introduction can greatly enhance the PMS activation performance of Mn 2 O 3 . For example, 100% of 2,4-DCP degradation can be obtained at 90 min over 4 wt% Ce doped Mn 2 O 3 at pH 7 (82.1% for Mn 2 O 3 at 90 min). The reaction rate constant ( k ) was also about 3.6 times higher than that of Mn 2 O 3 (0.0668 min −1 for Ce doped Mn 2 O 3 vs. 0.0186 min −1 for Mn 2 O 3 ). Besides 1 O 2 , OH and SO 4 − were identified and involved in 2,4-DCP degradation process over Ce doped Mn 2 O 3 , while only 1 O 2 was detected over 3D Mn 2 O 3 . Moreover, the contribution of OH and SO 4 − to 2,4-DCP degradation can be regulated by adjusting the Ce doping amount. The key role of Ce substitution in the regulation of reactive oxygen species was further investigated by XPS and electrochemical experiments. The Ce dopant can lead to a higher current density and greater reductive capability due to the improved charge transfer capability, which is important to the generation of more aggressive OH and SO 4 − and complete 2,4-DCP degradation.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2020
·Vol. 10
·期 3
·864-875
·
IF 5.721
Yang Li,Didi Li,Shisuo Fan,Ting Yang,Qi Zhou
In this work, novel dumbbell-like Mn2O3 was prepared using a low-cost and environmentally friendly template (gelatin) and applied to activate peroxymonosulfate (PMS) for pollutant degradation. The characterization results showed that dumbbell-like microstructures were formed by the self-assembly of tiny nanoparticles. Mn2O3-G (gelatin as the template) as a heterogeneous catalyst for PMS activation could effectively degrade various pollutants and exhibited an excellent degradation rate of rhodamine B (0.2333 min−1, in 30 min) for PMS activation compared to Mn2O3-C (carboxymethyl cellulose as the template), Mn2O3-N (without a template), and MnO2. The superior catalytic performance of Mn2O3-G was ascribed to its high oxygen vacancy content. The radical scavenging and EPR experiments revealed that SO4˙−, OH˙, O2˙−, and 1O2 were identified as reactive species generated from PMS activation. The oxygen vacancies participated in the generation of the reactive species. Thus, a facile and environmentally friendly method is provided for the synthesis of dumbbell-like Mn2O3 as a high-efficiency catalyst for PMS activation. Furthermore, this study shows a new mechanistic insight into PMS activation on Mn2O3.
研究领域:
环境科学
·
催化
·
污染控制
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2022
·Vol. 169
·期 5
·050530
·
IF 4.386
Kexing Cai,Shao-Hua Luo,Jun Cong,Kun Li,Sheng-xue Yan,Peng-qing Hou,Qing Wang,Yahui Zhang,Xin Liu
As one of the multivalent ion batteries, the zinc ion battery has the advantages of high-volume energy density and good safety. In this paper, coral-like and nanoparticle crosslinking hierarchical nanostructured ZnMn2O4/Mn2O3 composites were successfully synthesized as cathode materials for zinc ion batteries by a simple sol-gel combined with the zinc-absent method. ZnMn2O4/Mn2O3 composites with good properties were prepared when the zinc content was 10%. The prepared ZnMn2O4/Mn2O3 composites have the morphology of coral-like and nanoparticle crosslinking and uniform particle size distribution. Compared with pure ZnMn2O4 and Mn2O3, the composites show excellent electrochemical properties. Using 0.5 M Zn(CF3SO3)2-AN/H2O (8:2) as the electrolyte, the first discharge capacity of the material can reach 170.7 mAh·g−1 at 0.05 C. After 150 cycles, the discharge capacity remained 109 mAh·g−1. The kinetic characteristic of the electrode was studied by the galvanostatic intermittent titration technique, and the electrochemical reaction mechanism was studied by ex situ XRD. It was found that the two-phase recombination improved the diffusion rate of Zn2+. In the field of aqueous zinc ion batteries, an effective modification idea is provided for the research of spinel ZnMn2O4 cathode material with low specific capacity.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Zhiqun Xie,Zhiping Lyu,Jinnan Wang,Aimin Li,Philippe François-Xavier Corvini
Ultrafine-Mn 2 O 3 @N-doped porous carbon hybrids [Mn 2 O 3 @NC] derived from Mn-MOFs was constructed with 1 O 2 and O 2 −• as main Reactive oxygen species (ROS). Cation-π bonds and N-Mn complexation induced the formation of electron-rich Mn centre which provided electron for peroxymonosulfate activation to produce radicals, accompanying with generation of 1 O 2 via chain reaction. Notably, the porous structure of N-doped carbon shell could not only facilitate free radical recombination for generation of 1 O 2 but also provide adsorption sites for organics. On the other hand, as electron-poor centre, N-doped carbon shell could improve the electrons transfer from organic intermediate radicals to electron-rich Mn centre via π -π reaction, C-O-Mn and C-N-Mn bonds, which promote the redox of Mn to avoid peroxymonosulfate invalid decomposition. Being attributed to synergistic effects of dual-reaction centres and strong oxidation ability of 1 O 2 , Mn 2 O 3 @NC achieved high mineralization of BPA at low-dose peroxymonosulfate (0.033 g/L).
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2023
·
IF 4.6
Mohamed S. Selim,Nesreen A. Fatthallah,Shimaa A. Higazy,Xiang Chen,Zhifeng Hao
For the first time, we developed a novel nanocomposite of RGO decorated with α-Mn 2 O 3 nanorods (NRs) for inhibiting microbially influenced corrosion . RGO sheets with 2 nm thick were effectively synthesized by the modified Hummers technique and then a hydrothermal reduction procedure. The fabricated RGO/α-Mn 2 O 3 nanocomposite exhibited controlled morphology, geometry, surface exposure, and orientation. Single crystal α-Mn 2 O 3 NRs with mean diameter of 50 nm and length of 1 μm were produced via the hydrothermal procedure to yield γ-manganite which was calcined at 700 °C. Stable RGO/α-Mn 2 O 3 nanocomposite was successfully prepared via an efficient two-phase ultrasonication approach. The structures of the developed materials and nanocomposite were detected via different characterization techniques. Cost-effectiveness, long-term antimicrobial activity, and biocorrosion inhibition are the major advantages of the produced RGO/α-Mn 2 O 3 nanocomposite. The nanocomposite's biocorrosion-protection was influenced by its high surface area and controlled size and morphology. Its antimicrobial mechanism against different anaerobic and aerobic microbial strains was deeply highlighted. Field emission SEM images showed that the blade-like RGO/α-Mn 2 O 3 nanocomposite cruelly attached into the microbial cell walls forming morphology disruption, cell wrapping, and microbial killing. This nanocomposite exhibited ultrahigh potency against the anaerobic sulfate-reducing bacteria (SRB) strain Desulfovibrio halophilus SL 890 at 150 mg/L. Its highest potency against most of the tested aerobic strains was achieved at 2 μg/mL for Kocuria rhizophila EMCC 1246, Bacillus subtilis EMCCN 1152, Pseudomonas aeruginosa NRRL B-800, Staphylococcus aureus ATCC 25923, Aspergillus brasiliensis ATCC 9642 , and Candida albicans ATCC 24433. The designed RGO/α-Mn 2 O 3 nanocomposite provide a new platform for microbial growth inhibition.
研究领域:
材料科学
·
微生物学
✓ 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）