Journal of Environmental Chemical Engineering
·
2021
·
IF 5.909
Liying Jiang,Zhiwei Yao,Pengju Wang,Jianmeng Chen,Yufen Zhang,Wu Huang,Xiang Cao,Yufeng Xu
Plasma-catalytic removal of chlorobenzene (CB) was conducted in a dielectric barrier discharge (DBD) reactor over two manganese-based catalysts, LaMnO 3 and cryptomelane-type octahedral molecular sieve (OMS-2). The physicochemical properties of two catalysts were characterized by XRD , SEM, TEM , BET, XPS and H 2 -TPR. It was shown that OMS-2 catalyst had larger surface area, smaller particle size, better redox properties, higher ratio of Mn 4+ /Mn 3+ and higher content of surface-adsorbed oxygen (O ads ). The introduction of manganese-based catalysts enhanced CB removal, increased the CO 2 selectivity , and inhibited ozone (O 3 ) and NO x formation. OMS-2 exhibited a better degradation, mineralization and energy yield, with 89.5% of CB degradation, 57.6% of CO 2 selectivity and 0.54 g kWh −1 at discharge voltage of 6 kV, than LaMnO 3 in the NTP-catalytic reactor and this was ascribed to more active sites, more O ads , higher redox property and better O 3 decomposition ability on OMS catalyst surface. The two manganese-based catalysts were stable in the NTP-catalysis system although some intermediate byproducts were deposited on the catalyst surface during the 24-h activity cycling tests. Moreover, the intermediate byproducts were analyzed by GC/MS, and then the possible degradation pathways of CB decomposition in the plasma-catalysis system were suggested.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 34
·14389-14400
·
IF 3.288
Wenyi Yu,Qianwei Liang,Yuwei Yin,Junjie Geng,Wei Chen,Xuanyi Tan,Hanjin Luo
Arsenite (As(III)) is more toxic and more difficult to remove from water than arsenate (As(V)). A new nano core–shell-structured K-OMS-2@UiO-66 (K-OMS-2, formula KMn8O16·nH2O) was fabricated via a facile one-step oxidation–coprecipitation method for enhanced As(III) removal. Results showed that the maximal adsorption capacity of As(III) achieved was 180.10 mg g−1. The as-synthesized K-OMS-2@UiO-66 adsorbent functions excellently across a broad pH range of 1.5 to 10.0, and the residual concentrations of As(III) can drop under 10.0 μg L−1. Based on XPS and FTIR measurements, it is proposed that the removal mechanism was mainly controlled through a synergistic interaction of surface complexation and hydrogen bonding. As(III) was sorbed onto the surface of the sorbent by Zr–O bonds and Mn–O bonds. Mn(IV) and Mn(III) in K-OMS-2@UiO-66 effectively oxidized As(III) to As(V). Then, some negatively charged As(V) were adsorbed at the positive sites of the adsorbent through electrostatic attraction, while others formed bidentate complexes with the Zr–O bonds. This study develops an attractive sorbent for As(III) removal from contaminated water and has a facile and low-cost synthesis process, good As(III) sorption performance, and reusability.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2019
·
IF 7.65
Jiafei Su,Cuilian Cheng,Yaping Guo,He Xu,Qinfei Ke
Cryptomelane-type octahedral molecular sieve (OMS-2) catalysts are currently attracting tremendous attention due to their low-cost and remarkable thermo-catalytic activity. However, it is still difficult for OMS-2 catalysts to completely degrade formaldehyde at relatively low or even ambient temperature. In this work, OMS-2 catalysts with different ratios of length to diameter were prepared and the OMS-2-s with the minim ratio of length to diameter (1–3) exhibited the best catalytic performance than the other samples. Then, the optimized OMS-2-s nanorods were loaded on the SiO 2 nanofibers via a simultaneous electrospining-spray strategy. The evaluation for the dynamic catalytic activities of the samples showed that, the T 50 (HCHO conversion reached to 50%) for the OMS-2/SiO 2 nanofibrous membranes was decreased by 24 °C than the OMS-2-s nanorods. Furthermore, in the static experiment of HCHO decomposition, the composite membrane could achieve a catalytic efficiency of 52.3% at 25 °C, much higher than that of the OMS-2-s nanorods (45.9%). This work offers a new strategy to improve the catalytic efficiency of OMS-2 by controlling the morphology and loading of OMS-2 nanorods, and also designs a kind of advanced nano OMS-2-based nanofibrous membranes with hierarchical nanostructures for the highly efficient formaldehyde elimination during the practical application.
研究领域:
材料科学
·
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Jun Li,Jia Fang,Long Gao,Jingwen Zhang,Xinchao Ruan,Aihua Xu,Xiaoxia Li
Low valent manganese species and surface oxygen vacancies in OMS-2 play an important role in catalytic reactions, and it is highly desirable and challenging to develop a feasible strategy of increasing the Mn(II) and Mn(III) species concentration in the oxide. Herein, the OMS-2/g-C 3 N 4 hybrids (OMS-2/CN) were prepared by a facile refluxing approach. It was found that the MnO x precursor from the reaction of KMnO 4 and MnSO 4 was transformed into OMS-2 nanofibers with the formation of more Mn(II) and Mn(III) species in OMS-2 and the destruction and oxidation of g-C 3 N 4. The hybrids exhibited higher efficiency for pollutants degradation in the presence of PMS than the pure OMS-2 or g-C 3 N 4 . There was a linear correlation between the specific initial rate and the ratio of Mn(II + III)/Mn(IV). Mechanism investigation indicated that high active manganese species or caged radicals were produced through the oxidation of Mn(II) and Mn(III) by PMS and contributed to the degradation reaction. During five consecutive cycles, the catalyst exhibited good reusability and stability. Therefore, the OMS-2/CN hybrids are promising catalysts for wastewater treatment with PMS as the oxidant.
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
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2018
·
IF 5.091
Peng Ye,Qiancheng Zou,Luyang An,Yi Wei,Aihua Xu,Xiaoxia Li
Due to low cost and low toxicity, manganese oxides have been extensively explored to reduce organic pollutants in wastewater via peroxymonosulfate (PMS) activation; but the development of manganese-based catalysts with facile synthesis process at low temperatures and high efficiency is still of significant practical interest. In this paper, a simple room temperature method has been successfully developed to synthesize cryptomelane-type manganese octahedral molecular sieves (OMS-2) from KMnO 4 and MnSO 4 in the presence of carbon nanotubes (CNTs). The redox reaction between amorphous manganese oxide and CNTs results the decrease of manganese valences and the formation of OMS-2 phase at a low temperature of 25 °C. The changes of synthesis time, temperature and CNTs dosage altered the characteristics of the prepared materials. Compared with CNTs, OMS-2 and other manganese oxides hybrids, the synthesized catalysts demonstrated a remarkable efficiency for PMS activation to degrade organic dyes and a superior reusability during ten successive cycles. Sulfate radicals were formed as the active species in the system from the oxidation of low valent Mn species by PMS. This study not only provides a simple method to synthesize OMS-2 at room temperature, but also improves the understanding of PMS activation on manganese-based catalysts for pollutants degradation.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2017
·
IF 4.233
Jia Fang,Jun Li,Long Gao,Xiwang Jiang,Jingwen Zhang,Aihua Xu,Xiaoxia Li
The octahedral molecular sieve manganese oxide (OMS-2) and graphite (Gt) composites (OMS-2/Gt) were prepared by a facile refluxing approach. The structure and morphology of the obtained materials were systematically investigated. The results reveal that OMS-2 nanofibers are uniformly dispersed on the surface of Gt, and the ratio of Mn 3+ species in OMS-2 increases lineally with the increase of Gt dosage. The catalytic activity of OMS-2/Gt was evaluated by the degradation of Acid Orange 7 (AO7) in the presence of peroxymonosulfate (PMS). It is found that the OMS-2/Gt composites show enhanced catalytic performance with the degradation rate lineally correlated with the content of OMS-2 in the catalyst, and even with the ratio of Mn 3+ /Mn 4+ . XPS and radical scavenger experiments further indicated that the oxidation of Mn 3+ by PMS system occurs in the system with the formation of hydroxyl radicals contributed to the dye degradation . The catalysts also exhibit good stability and reusability during consecutive cycles. Thus, the environmental friendly OMS-2/Gt composites with low cost, facile synthesis process and high efficiency are very promising catalysts for PMS activation and pollutants degradation.
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
APPLIED ORGANOMETALLIC CHEMISTRY
·
2019
·Vol. 33
·期 6
·e4815
·
IF 3.259
Qiancheng Zou,Yi Wei,Shuai Wang,Jinyan Xie,Aihua Xu,Xiaoxia Li
The development of green and efficient catalysts for peroxymonosulfate (PMS) activation and organic pollutants degradation has received widespread attention. In this study, the hybrid CaCO 3 /OMS-2 catalysts were prepared by a simple precipitation approach and characterized by X-ray powder diffraction, N 2 adsorption–desorption, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and cyclic voltammetry. It was found that deposition of CaCO 3 on OMS-2 surface can weaken the Mn-O bond by formation of Ca-O-Mn bond. The interactions between CaCO 3 and OMS-2 significantly enhanced Acid Orange 7 degradation in the presence of PMS with a pseudo-first-order kinetic constant of 0.21 min −1 , which was much higher than those of OMS-2 (0.026 min −1 ) and CaCO 3 (0.021 min −1 ). The CaCO 3 /OMS catalysts were also much more efficient than other reported OMS-2 hybrid catalysts, and could be performed over a wide solution pH and for other organic dyes degradation. Sulfate and hydroxyl radicals were formed from the oxidation of low valent manganese species by PMS as the active species in the system. This study can provide a simple method for the design of efficient manganese-based hybrids for wastewater remediation via PMS activation.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 26
·12844-12855
·
IF 3.925
Ning Yang,Lixi Xiao,Yuwei Deng,Zhiyu Wu,Hang Yin,Yang Liu,Mengru Li,Yuxuan Ye,Dandan Wang,Qiang Li,Fei Pan,Dongsheng Xia
In this study, a novel catalyst was prepared by loading OMS-2 onto activated carbon fiber (ACF) via a one-step hydrothermal method, which was further adopted for carbamazepine treatment. SEM, TEM and XRD analyses indicate that OMS-2 was successfully loaded on ACF. In the OMS-2@ACF/UV/PMS system, the degradation rate of CBZ (20 mg L−1) was 98.1% and the mineralization rate was 53.3%, which were higher than those of the traditional UV/PMS process. The enhanced performance in the presence of OMS-2@ACF was attributed to the redox cycle between Mn2+/Mn3+/Mn4+, which then accelerated PMS activation to generate more active species. The primary reactive species, including SO4˙−, ˙OH, O2˙− and 1O2, were confirmed through EPR and radical capture experiments. Additionally, the material exhibited excellent reusability even after 5 cycles, and remarkable performance for CBZ degradation was found in real water samples.
研究领域:
环境科学
·
催化材料
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2015
·Vol. 39
·期 8
·6395-6403
·
IF 3.086
Mingyu Wei,Yang Ruan,Shilu Luo,Xiaoxia Li,Aihua Xu,Ping Zhang
A magnetically recyclable nanocomposite, manganese oxide octahedral molecular sieve (OMS-2) coated Fe3O4 nanoparticles, was prepared using a facile solvent-free process with manganese salts and Fe3O4 at a low temperature. XRD, SEM, TEM, FT-IR, XPS and N2 adsorption–desorption isotherm analysis showed that in the core–shell nanocomposite, OMS-2 was homogeneously distributed on the Fe3O4 surface with similar structures to that of pure OMS-2 but a much higher surface area of 251 m2 g−1. The catalyst exhibited excellent activity toward the degradation of Acid Orange 7 (AO7), Reactive Brilliant Blue KN-R, Reactive Brilliant Red X-3B, methylene blue, methyl orange, and rhodamine B in the presence of peroxymonosulfate (PMS), with nearly complete decolorization within 15 min. The catalyst could also be easily recovered with the assistance of an external magnetic field, and could be reused for ten successive cycles without any change of structure. The loss of Mn ions in solution was lower than 0.05 mg L−1 and no Fe ions were detected. The effect of several parameters, including the OMS-2 content in the nanocomposites, the concentration of AO7, PMS and the catalyst, and solution pH, on the degradation efficiency was also discussed.
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
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Zihui Jia,Yangyang Lv,Yu Guo,Qiaohui Gao,Hexiang Lan,Aimal Khan,Aihua Xu,Xiaoxia Li
The abundant and low-cost manganese oxides have attracted increasing interest in peroxymonosulfate (PMS) activation. Nevertheless, the low zeta potentials and surface area of the catalysts lead to weak adsorptions of PMS and pollutants under neutral and basic conditions, and thus the low degradation efficiency. Herein, a promising hybrid from graphite nanosheets (GNs) and cryptomelane-type manganese octahedral molecular sieves (OMS-2) was developed by a simple redox method at room temperature. The catalysts possessed a high surface area and a great number of surface defects , which enhanced the adsorption of PMS; while the introduction of GNs increased the capacity of pollutants adsorption and the rate of electron transfer. Compared with pure OMS-2 and other catalysts, the hybrid catalyst showed a much higher performance for acid orange 7 degradation at pH 8.2 with a first-order rate constant of 0.414 min −1 , due to the above synergistic effects between OMS-2 and GNs. Based on quenching experiments, PMS decomposition and degradation of pollutants with different oxidation potentials, a direct electron transfer process through Mn-O-PMS complexes was identified to contribute the degradation. Moreover, a galvanic oxidation system was set up to further confirm the occurrence of the mechanism. Overall, this work provides an important step in developing Mn-based hybrids for organic pollutants degradation.
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
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Shandi Zhong,Cai Xu,Quanfu Long,Hang Zhou,Jianhai Yang,Jia Guo,Xiaozhong Wang,Liyan Dai
Using O 2 as an oxidant, developing a non-noble metal catalyst for the selective catalytic C–H bond oxidation of p-chlorotoluene is desirable and challenging. In this work, a series of Co, Cr co-doped OMS-2 (Octahedral Molecular Sieve-2) catalysts were prepared by a conventional refluxing method. It was found that the incorporation of Co and Cr improved the catalytic activity for the selective oxidation of p-chlorotoluene to p-chlorobenzaldehyde. Among these catalysts, CoCr/OMS-2 (Co: Cr = 1: 1, mass ratio), the best catalyst, shows that the conversion and the selectivity of p-chlorobenzaldehyde is 94.8 % and 94.3 %, respectively. The enhanced catalytic activity was due to the larger specific surface area and even dispersion of active components. The characterization results also disclosed that the co-doping of Co and Cr increased the oxygen vacancy and enhanced the ability to activate the surface lattice oxygen. Additionally, density functional theory calculations demonstrated that co-doping of Co and Cr promoted the adsorption of p-chlorotoluene and O 2 , and decreased the energy barrier of rate-determining step (the conversion of p-chlorobenzyl alcohol to p-chlorobenzaldehyde). Besides, when H 2 O was added to the reaction system as the second solvent, the activation and dissociation of O 2 , and the formation of p-chlorobenzaldehyde were facilitated, in agreement with the experimental results. This work demonstrated the promotional effect of Co, Cr co-doped into OMS-2 catalyst and the role of H 2 O for the selective oxidation of p-chlorotoluene.
研究领域:
催化化学
·
材料科学
·
环境化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2025
·
IF 7.3
Jun Zhang,Lanyu Luo,Jiankun Wang,Xinlan Xu,Tiantian Peng,Boyu Liu,Lingying Jiang,Meng Jin,Weimin Wu,Laizheng Luo,Huan Yi,Shi-Yu Lu
Optimizing the electronic configuration presents a promising approach to enhance intrinsic activity and minimize noble metal use in direct methanol fuel cells (DMFCs). Metal–support interactions, commonly employed to induce interfacial charge redistribution, play a crucial role in this optimization. This study successfully synthesized a Pd/O-OMS-2 electrocatalyst characterized by Pd–O–Mn interfacial chemical bonds and Mn3+/Mn4+ redox couples, serving as a stable bifunctional catalyst for both the oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR). Unlike the mixed Pd–O/Mn bonds in Pd/O/Mn-OMS-2, the Pd–O–Mn bonds in Pd/O-OMS-2 not only enhance metal–support interactions and promote uniform dispersion of Pd nanoparticles but also facilitate electron transfer and the conversion between Mn3+ and Mn4+. These structural and compositional advantages endow the Pd/O-OMS-2 catalyst with superior ORR and MOR performance. The catalyst achieves a higher half-wave potential (E1/2) of 0.901 V, a mass activity of 0.937 A mgPd–1, and enhanced methanol permeability, outperforming Pd/O/Mn-OMS-2, Pd/OMS-2 and commercial Pd/C catalysts. Moreover, in an alkaline electrolyte, the Pd/O-OMS-2 catalyst follows a typical four-electron reaction pathway for ORR (O2 to H2O) and promotes faster reaction kinetics and charge transfer rates. In terms of durability, the Pd/O-OMS-2 catalyst exhibits minimal E1/2 decay (8 mV) and retains its structural integrity even after 10,000 cyclic voltammetry (CV) cycles. Additionally, it demonstrates the highest mass activity and stability during the MOR process. The exceptional ORR/MOR performance can be attributed to the synergistic effect of strong metal–support interactions, high Pd nanoparticle dispersion, and increased Mn3+ active species. The construction of interfacial chemical bonds offers a prospective strategy to optimize electronic configurations and develop advanced bifunctional electrocatalysts for ORR and MOR.
研究领域:
电化学
·
催化材料
·
能源材料
✓ 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）