CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Zhi Liu,Chong Chen,Jinchong Zhao,Lingzhi Yang,Kaian Sun,Lingyou Zeng,Yuan Pan,Yunqi Liu,Chenguang Liu
Selective catalytic reduction of NO by NH 3 (SCR) at low temperature usually considered to be the combination of NO oxidation and “Fast SCR” process. However, the NO oxidation mechanism and the role of NO 2 over “Fast SCR” process are controversial. Focusing on these problems, the in-deep studies were performed over the typical MnO x /TiO 2 catalysts. Combining in-situ DRIFT, TPD-MS and DFT calculation results, an integrated NO oxidation mechanism was proposed based on an “Nitro-assisted oxygen activation” concept where the activation and transformation of O 2 is linked with the transformation of nitro species. The O O bond of O 2 can be weakened by generating a variation of bidentate nitrates, which can promote the break of O O bond and the formation of NO 2 . The formation of the variation of bidentate nitrates was the rate-determining step over NO oxidation. Additionally, we further reveal that the crucial role of NO 2 over “Fast SCR” process lies in participating the hydrogen abstraction from coordinated NH 3 and promoting the production of NH 2 active species which can direct react with NO to generate N 2 and H 2 O. The removability of NO 2 can coupling the MnO 2 (NO oxidation active component) and TiO 2 support (“Fast SCR” active component) together. Our findings provide insight into the design and improvement of catalysts or reaction pathways over the low-temperature SCR process.
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 NANOPARTICLE RESEARCH
·
2019
·Vol. 21
·期 4
·1-7
·
IF 2.009
Xie Chong,Shi Jian-Wen,Yang Shenghui,Li Xifei
The MnO x -TiO 2 /MWCNTs nanocomposites were used as De-NO x catalysts to study the deep-rooted reason for the deactivation. Based on a series of characterization on as-prepared catalyst and poisoned catalyst, the results showed that the chief culprit for the deactivation is the micropores in the De-NO x catalyst. The formed ammonium (bi)sulfate in the micropores during the SCR reaction process could not be took away by the gas flow soon and then deposited on the catalyst surface gradually, and further covered the active sites. And the poisoned catalysts could be recovered partly rather than fully by heat treatment at 500 °C because of the decomposition of the ammonium (bi)sulfate and the phase transition of the TiO 2 .
研究领域:
环境催化
·
纳米材料科学
·
大气污染控制
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Kangning Wang,Mengran Qin,Chuantao Wang,Ting Yan,Yanzhong Zhen,Xiaolei Sun,Jianwei Wang,Feng Fu
The construction of composite materials is an effective strategy to solve the problems of poor conductivity, manganese dissolution, and volume expansion of manganese-based materials. Herein, a CeO 2 /MnO x @C hollow composite cathode derived from the self-assembly of Ce-Mn-metal-organic frameworks (Ce-Mn-MOFs) was synthesized. The abundant oxygen vacancies and good electronic/ionic conductivity of CeO 2 improve the electrical conductivity of composite, enhancing the rate performance. The unique hollow structure could inhibit manganese dissolution and alleviate volume expansion. The results indicate that the 1 % CeO 2 /MnO x @C composite cathode possesses a high reversible capacity and excellent cycling stability. Specifically, the 1 % CeO 2 /MnO x @C composite cathode shows a remarkable reversible specific capacity of 130 mAh/g at a current density of 500 mA g −1 , 6.5 times more than the pure MnO x (20 mAh/g). The capacity retention is up to 99.5 % relative to the initial capacity after 800 cycles. This study provides a new strategy for designing rare-earth composite electrodes to improve electrochemical performance.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Ying Huang,Juan Lei,Baobao Bai,Xiaoli Ren,Lijun Cheng,Yu Cao,Shuang Wang,Jinping Li
Traditional powder catalysts are not suitable for industrial applications due to low utilization of active phase and easy sintering. Therefore, monolithic catalyst MCCF with good stability and water-resistance was designed for the catalytic oxidation of toluene-acetone mixture, in which amorphous MnO x derived via pyrolysis of Mn-MOFs loaded on copper foam (CF) and different transition layers were employed between MnO x and CF to regulate Cu-Mn interaction. The combined action of amorphous MnO x and the Cu-Mn strong interaction enhanced the catalytic degradation of toluene-acetone mixture. The existence of amorphous MnO x and the impacts of Cu-Mn interaction on weakening Mn-O bonds and stimulating reactive oxygen species were verified by various characterizations. Furthermore, the reaction pathways of toluene and acetone on catalyst MCCF were revealed as well as their interactions within the mixture.
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
·
2021
·
IF 6.707
Qiuyu Feng,Biyuan Liu,Jian Ji,Kai Li,Boge Zhang,Haibao Huang
Traditional photocatalytic oxidation of volatile organic compounds (VOCs) suffers low oxidation and mineralization capability, the short lifetime of the lamps, etc. The usage of microwave discharge electrodeless lamps (MDELs) is an energetic approach to eliminate pollutants with lamps having a long lifetime. Herein, a novel MDELs-photocatalytic system using MnO x /TiO 2 /activated carbon (AC) as the photocatalyst was explored to degrade toluene. The system displayed a superior toluene removal efficiency (94%) and mineralization rate (91%), and there was nearly no ozone emission. Owing to the formation of MnTiO 3 , the photocatalytic degradation activity over MnO x /TiO 2 /AC was remarkably increased by producing more reactive oxygen species, such as O( 1 D) and OH · . MnO and MnTiO 3 in MnO x /TiO 2 /AC also promoted the decomposition of ozone to further degrade toluene via catalytic ozonation. Moreover, the excellent microwave absorbing property of MnO x /TiO 2 /AC increased the catalyst bed temperature to nearly 150 °C, accelerating the thermal decomposition of toluene due to the “hot spots” effect. The degradation mechanism was proposed tentatively. This work shed new light on the effective removal of VOCs using a novel MDELs photodegradation system over multi-functional catalysts.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2016
·Vol. 45
·期 26
·10530-10538
·
IF 4.177
Hui Hua Peng,Jie Chen,De Yi Jiang,Xiao Long Guo,Hao Chen,Yu Xin Zhang
MnOx-decorated MgAl layered double oxide (M-LDO) was fabricated via merging of memory effect and anion intercalation, accompanied by the reduction/calcination process. The as-obtained nanocomposites were characterized by scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), powder X-ray diffraction (XRD) and N2 adsorption–desorption. To clarify the detailed formation mechanism, optimized calcination temperature/time and temperature for methyl orange (MO) adsorption were investigated. Adsorption experiments showed that the adsorption behaviour fitted well with a Langmuir isotherm and pseudo-second-order model, and the maximum adsorption capacity calculated from the Langmuir model was 555.55 mg g−1. The adsorption process was exothermic and spontaneous in nature. Moreover, the used adsorbent could be regenerated for at least five cycles (94% removal retained) through a thermal procedure, indicating that the M-LDO hybrid is a promising adsorbent with promising ability to remove anionic dye pollutants from wastewater.
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
GREEN CHEMISTRY
·
2018
·Vol. 20
·期 15
·3593-3603
·
IF 8.586
Shenghui Zhou,Guixian Chen,Xiao Feng,Ming Wang,Tao Song,Detao Liu,Fachuang Lu,Haisong Qi
Herein, we report a sustainable route to in situ synthesize a monolithic MnOx/N-doped carbon aerogel catalyst (Mn-NCA) by pyrolysing MnO(OH)2-cellulose aerogel precursors based on an alkali–urea aqueous system. The as-obtained Mn-NCA showed highly efficient catalytic activity for the transfer hydrogenation of a broad range of biomass-derived aldehydes, yielding 90–100% conversion and 64–100% selectivity to the corresponding alcohols under mild conditions in an oven without agitation. A combination of controlled experiments and detailed characterization studies indicated that the superior performance of Mn-NCA is attributed to the monolithic three-dimensional (3D) hierarchical porous architecture and the synergistic effects between homogeneously dispersed MnOx nanoparticles (NPs) and urea-derived basic sites. The monolithic feature of Mn-NCA exhibits superior dispersibility and separability compared to conventional centrifugation and filtration techniques in a powdery catalytic system. Moreover, a possible reaction mechanism is proposed. Our work provides a new method for developing highly efficient monolithic catalysts from renewable biopolymers for biomass valorization.
研究领域:
材料科学
·
催化化学
·
可再生资源利用
✓ 已验证
DOI
高影响因子
Biomaterials Science
·
2023
·Vol. 11
·期 6
·2056-2064
·
IF 6.6
Fen Yang,Xuan Wang,Jie Sun,Sijia Tan,Shizhe Zhou,Wenlong Tu,Xuexue Dong,Qicai Xiao,Fu Yang,Liqian Gao
Autophagy induced by nanomaterials is one of the intracellular catabolic pathways that degrade and recycle the biomacromolecules and damaged organelles in cells and has emerged as a very promising pharmacological target critical to future drug development and anti-cancer therapy. Herein, we developed mesopore-encaged highly-dispersed active cluster-like MnOx in nanosilica entitled MnO-MS, with a size of around 130 nm. Our studies show that MnO-MS could not only obviously induce autophagy in both stable GFP-LC3 HeLa cells and GFP-LC3-mCherry HeLa cells but also could selectively inhibit lung cancer A549 cell growth at 11.19 μg mL−1 (IC50) while exhibiting little cytotoxicity in normal cells. Encouraged by these interesting results, a further mechanistic study reveals that reactive oxygen species (ROS) were excited by the active MnOx in nanosilica, leading to the disruption of mitochondrial membrane potential (MMP), enhancement of ATG5A/ATG16L/ATG4B/Beclin1, and finally, inhibition of the mTOR signaling pathways. Collectively, these findings indicate that MnO-MS-induced cell death via autophagy pathways in cancer cells. Furthermore, MnO-MS significantly inhibited tumor growth with minimal side effects in vivo, and it is envisioned that MnO-MS can be further developed as a potential autophagy inducer for the treatment of lung cancers.
研究领域:
纳米技术
·
癌症生物学
·
药理学
·
细胞生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2019
·Vol. 43
·期 48
·19020-19034
·
IF 3.069
Fu Yang,Shuying Gao,Yun Ding,Sheng Tang,Haifeng Chen,Jianjun Chen,Jianfeng Liu,Zhen Yang,Xiaocai Hu,Aihua Yuan
The confinement of refined catalytically active substances in special nanospaces is beneficial for promoting reaction processes by taking advantage of the quantum confinement effect and enlarged atomic efficiency. Herein, we present a redox nanoporous molecular sieve nanocatalyst containing size-confined active MnOx in the siliceous nanospace of mesopores via a functional micelle-assisted in situ embedding strategy. We also demonstrate its excellent environmental catalytic efficiency toward the oxidative degradation of methyl orange in the liquid phase (8 min) and volatile toluene in the gas phase (T90/T100 = 225/240 °C, under the mass space velocity of 60 000 ml g−1 h−1 and concentration of 1000 ppm, which surpass noble metal catalysts and most composite catalysts). This was achieved by virtue of eliminating diffusion limitations, and great active atom-efficiency. In this synthetic strategy, the well-made resultant MnOx had a refined size and greater interaction with diffusing reactant molecules without impeding their diffusion and mass transfer. Excellent and durable catalytic efficiency was demonstrated, due to the superior characteristics concerning the great dispersion of MnOx and favorable structure, thereby confirming that high catalytic removal efficiency depends on the amount of accessible MnOx rather than the loading of active species. Our findings provide the first example of a heterogeneous environmental catalyst that affords highly efficient catalytic elimination of organic contaminants in both liquid and gaseous systems.
研究领域:
环境科学
·
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
IONICS
·
2025
·
IF 2.6
Wang Yao,Wu Yidi,Zhang Pengzhan,Xu Bing,Wang Kangkang,Zhang Liang,He Zhixian,Zhang Shengnan
The novel MnO x /CN/Ag composite was prepared by the precipitation method. The structure and morphology of the material were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Light absorption capacity, charge transfer efficiency, and carrier recombination ability were evaluated using UV–Vis diffuse reflectance (UV–Vis DRS) spectroscopy, electrochemical impedance spectroscopy (EIS), photoluminescence (PL) spectroscopy, and transient photocurrent response (TPR). The photothermal catalytic performance toward toluene and tetracycline hydrochloride (TC) was assessed, and the reduction properties were analyzed by H 2 -temperature programmed reduction (H 2 -TPR). The results show that the MnO x /CN/Ag composite achieves a degradation efficiency of 97% for toluene at 260℃ and a TC degradation efficiency of nearly 80%. No obvious attenuation was observed after 360 min of continuous reaction. The superior catalytic performance and stability of the composite can be attributed to the abundant oxygen vacancies and low reduction temperature. This work not only provides a novel photothermal catalytic material for enhancing VOC degradation but also offers insights into the treatment of multiple environmental pollutants. Graphical abstract
研究领域:
环境科学
·
材料科学
·
催化
·
纳米技术
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2019
·Vol. 128
·期 2
·681-693
·
IF 1.428
Xie Chong,Yang Shenghui,Shi Jian-Wen,Niu Chunming
A novel MnO x –TiO 2 catalyst with hollow silkworm structure was synthesized successfully via an ethanol-thermal strategy by using activated carbon fiber felt as template for the first time. The silkworm-like MnO x –TiO 2 catalyst (MnTi) exhibited higher NO x conversion in the whole experimental temperature region (90–330 °C) under a high space velocity of 36,000 h −1 in comparison with the common MnO x –TiO 2 catalyst without hollow silkworm structure (MnTi-B). The excellent catalytic performance of MnTi can be attributed to its high specific surface area, large content of active surface oxygen species (O S ), and more surface acid sites. In addition, the MnTi catalyst also exhibited excellent resistance to water or SO 2 poisoning.
研究领域:
催化化学
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Fada Feng,Yikui Zeng,Dengfeng Yan,Quanming Ren,Bang Lan,Jinping Zhong,Biyuan Liu,Tao Dong,Haibao Huang
To clarify the key role of oxygen vacancy defects on enhancing the oxidative activity of the catalysts, metal–organic frameworks (MOFs) derived MnO X catalysts with different morphologies and oxygen vacancy defects were successfully prepared using a facile in-situ self-assembly strategy with different alkali moderators. The obtained morphologies included three-dimensional (3D) triangular cone stacked MnO X hollow sphere (MnO X -H) and 3D nanoparticle stacked MnO X nanosphere (MnO X -N). Compared to MnO X -N, MnO X -H exhibited higher activity for the oxidation of toluene (T 90 = 226 °C). This was mainly due to the large number of oxygen vacancy defects and Mn 4+ species in the MnO X -H catalyst. In addition, the hollow structure of MnO X -H not only facilitated toluene adsorption and activation of toluene and also provided more active sites for toluene oxidation. Reaction mechanism studies showed that the conversion of toluene to benzoate could be realized over MnO X -H catalyst during toluene adsorption at room temperature. In addition, abundant oxygen vacancy defects can accelerate the activated oxidation of toluene and the formation of oxidation products during toluene oxidation.
研究领域:
催化材料科学
·
环境科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）