Journal of Environmental Chemical Engineering
·
2020
·
IF 4.3
Qun Wang,Ming Ma,Xiaohong Wu,Wei Qin
Understanding carrier dynamic behavior including carrier lifetime and concentration, electrochemical behavior and band structure of the MAPbX 3 (X = I, Br) with high crystal quality are important for improving photocatalytic applications. Herein, a facile isopropanol-assisted solvothermal strategy was demonstrated for highly yielding synthesis MAPbX 3 (X = I, Br) cubic microcrystals with high crystallinity for degrading water insoluble dyes in an organic solvent system. Supported by time-dependent morphology evolution experimental evidence, a high temperature gradient inside the solution leads to natural convection which can induce the screw dislocation in microcrystals. The XRD, IR, steady-state photoluminescence (PL) spectra, fluorescence lifetimes UV–vis spectra and electrochemical tests were investigated to found a direct correlation between crystal quality (crystallinity and defects) and optical properties (PL intensity and bandgap). Importantly, MAPbBr 3 displayed almost an order of magnitude more efficient photocatalytic degradation of malachite green (MG) dye in isopropanol solvent relative to those of MAPbI 3 , which was ascribed to good stability and superior photoinduced electron transfer for molecular oxygen activation.
研究领域:
材料科学
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化学
·
光催化
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
IF 5.774
Fangke Yu,Yi Wang,Hongrui Ma,Minghua Zhou
In this study, we demonstrated that hydrothermal synthesized FeS 2 was highly efficient to catalyze the H 2 O 2 decomposition for diclofenac sodium (DCF) degradation in a wide range of initial pH (3–9) by heterogeneous electro-Fenton (EF) process, and this “Pyrite-EF” showed a better performance for the mineralization of DCF in comparison with the classic EF process. Effect of pyrite content on the hydroxyl radicals generation and iron dissolution produced by the decomposition of hydrogen peroxide (H 2 O 2 ), and applied current density on the degradation kinetics and mineralization efficiency were studied. Moreover, toxicity assessment by means of microtox method showed the solution toxicity was removed after treatment. Experimental results revealed that the enhancement of DCF degradation rate in the Pyrite-EF process was attributed to the molecular oxygen activation induced by more surface bound ferrous ions on FeS 2 , generating superoxide anions to accelerate the Fe(II)/Fe(III) cycle on the FeS 2 surface, which favored the H 2 O 2 decomposition to generate more hydroxyl radicals for the DCF degradation via a heterogeneous EF-like process. These findings could provide some new insights into the molecular oxygen activation induced by FeS 2 and the subsequent heterogeneous Pyrite-EF degradation of organic pollutants from wastewater.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
CATALYSIS TODAY
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2017
·
IF 4.636
Xuli Zhuang,Xinli Tong,Yongtao Yan,Song Xue,Linhao Yu,Yongdan Li
A highly efficient and selective transformation of lignin-derived vanillin and vanillyl alcohol to prepare methyl vanillate has been developed in the presence of molecular oxygen. A series of supported Au, Pd and Pt catalysts were prepared and employed for the selective oxidation of vanillin. It is found that, in the presence of Au-h/Al 2 O 3 catalyst, a 98.1% conversion of vanillin and 99.9% selectivity of methyl vanillate was obtained in methanol under 0.3 MPa of O 2 at 140 °C for 4 h. Moreover, the oxidative esterifications of isovanillin, syringaldehyde, p -anisaldehyde and 3, 4, 5- trimethoxybenzaldehyde were successfully performed, and 70.2–98.0% yields of methyl aromatic esters are obtained. The recycling experiment showed that the Au-h/Al 2 O 3 still keep a high catalytic activity after being reused five times. Next, the oxidation of vanilly alcohol was studied, and 99.9% conversion and 99.6% selectivity of methyl vanillate was attained at 140 °C for 12 h with the Au-h/Al 2 O 3 as catalyst. Finally, based on the reaction phenomena and experimental results, a possible reaction mechanism for the oxidation of vanillyl alcohol is proposed.
研究领域:
化学工程
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催化科学
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DOI
高影响因子
CATALYSIS COMMUNICATIONS
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2016
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IF 3.389
Jinyan Sun,Xinli Tong,Zonghui Liu,Shengyun Liao,Xuli Zhuang,Song Xue
A selectivity-switchable oxidation of benzyl alcohol by molecular oxygen is achieved with the iron doped graphene (Fe Gr) supported gold catalysts. The oxidative esterification process is dominant with Au/Fe Gr and K 2 CO 3 as the catalyst in methanol where a 96.2% conversion of benzyl alcohol and 99.9% selectivity of methyl benzoate were obtained. While, the oxidation of benzyl alcohol is orientated to produce benzaldehyde in n-butanol using Au Pd/Fe Gr as the catalyst, in which an 89.1% conversion and 87.5% selectivity of benzaldehyde was attained. Moreover, the effects of the additive, reaction medium and reaction time were investigated. Also, the oxidation of different benzylic alcohols was successfully performed under the optimal conditions. Furthermore, the used catalysts were characterized by XRD, NH 3 -TPD, SEM, Roman, TG-DTA and BET techniques. Based on the experimental results and phenomena, a possible reaction mechanism is proposed for the selective oxidation of benzyl alcohol with molecular oxygen in which alkyl benzoate is produce through the hemiacetal intermediate of benzaldehyde with short chain alcohol, and the generation rate of hemiacetal decides the selectivity of product.
研究领域:
化学
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催化科学
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产品关联
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2022
·
IF 5.477
Binxiong Guang,Yiwei Zhang,Yahui Xiao,Miaojun Su,Xiying Li,Yong Liu
Background It is of great significance but still a challenge in the chemical industry to develop high-efficient heterogeneous catalysts for selective oxidation of styrene into benzaldehyde with molecular oxygen. Methods Fe 3 C nanoparticles confined in N-doped carbons (Fe 3 C/NC) were prepared using Fe 3+ coordinated N-bearing ionic liquids as precursors and melamine as nitrogen source and template, followed by pyrolysis at 900 °C under N 2 atmosphere. The physicochemical properties of the as-prepared Fe 3 C/NC catalyst were analyzed by FT-IR, TG, BET, TEM, XRD, Raman and XPS, respectively, and further employed as novel heterogeneous catalyst for selective oxidation of styrene into benzaldehyde with molecular oxygen. Significant findings The results showed that the Fe 3 C nanoparticles were formed and uniformly embedded into the N-doped carbon matrix, which were confirmed to be the active sites for styrene oxidation. Moreover, the 5 % Fe 3 C/NC catalyst possessed high surface area and dominant mesoporous structure, which could expose more accessible active sites and facilitate mass transfer. As a result, the 5 % Fe 3 C/NC catalyst exhibited superior catalytic performance for styrene oxidation into benzaldehyde with the appropriate styrene conversion of 58.8 % and selectivity to benzaldehyde of 64.1 % as well as no significant activity and selectivity loss after reused at least five times.
研究领域:
催化化学
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材料科学
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2016
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IF 5.31
Wenjuan Shen,Fangjing Lin,Xu Jiang,Hefei Li,Zhihui Ai,Lizhi Zhang
In this study, we systematically investigated the removal of bromate (BrO 3 − ) with core-shell Fe@Fe 2 O 3 nanowires at neutral pH, especially the effects of surface bound ferrous ions and molecular oxygen. In the presence of Fe@Fe 2 O 3 nanowires, bromate was reduced to Br − efficiently with the generation of HOBr intermediates. Bromide species analyses and nanowires characterizations indicated that surface bound ferrous ions of core-shell Fe@Fe 2 O 3 nanowires could effectively promote the BrO 3 − removal. Meanwhile, molecular oxygen competed electrons from both Fe 2+ and Fe 0 to generate reactive oxygen species of O 2 − , H 2 O 2 , and OH during the bromate removal process. Among the generated reactive oxygen species, O 2 − and H 2 O 2 favored of bromate removal, but OH inhibited. We proposed a bromate removal mechanism with core-shell Fe@Fe 2 O 3 nanowires, which suggested that the effect of surface bound Fe(II) and molecular oxygen was taken into consideration when using nZVI for bromate remediation in waters. This study can not only deepen our understanding on the bromate removal with zero valent iron, and also shed light on the design of high performance bromate removal materials.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
Frontiers in Chemistry
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2019
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IF 3.782
Song Hongbing,Liu Zong,Gai Hengjun,Wang Yongjie,Qiao Lin,Zhong Caiyun,Yin Xiangyang,Xiao Meng
Introducing electron-rich nitrogen atoms to ordered mesoporous carbons (OMC) as supports for noble metal catalysts, not only improves the hydrophilic properties of a mesoporous carbon surface, but also enhances the coordination and binding abilities of metal ion. In the present work, nitrogen-doped ordered mesoporous carbons (NOMCs) were successfully fabricated via a facile hydrothermal self-assembly. The prepared NOMCs were characterized through powder X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption-desorption isotherm. The analyses demonstrated that the NOMCs prepared at a pyrolysis temperature of 750°C possessed an ordered 2D hexagonal mesoporous structure, a high graphitization degree, large surface area, and a well-distributed pore size. In particular, NOMCs could anchor Pd nanoparticles uniformly because of the introducing N atoms with strong electronegativity, which were selected as efficient catalysts for the partial oxidation of benzyl alcohol to benzaldehyde. Approximately 24.63% conversion with 85.71% selectivity to benzaldehyde was obtained without using any solvent by molecular O2 oxidation. Most importantly, the TOF value of the catalyst in the reaction system was up to 8698 h−1. After five runs reaction, TOF and selectivity of the catalyst remained essentially same. Hence, the proposed catalyst has a potential engineering application value.
研究领域:
材料科学
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催化化学
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DOI
PubMed
高影响因子
Green Energy & Environment
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2025
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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
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催化反应
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材料科学
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产品关联
DOI
高影响因子
WATER RESEARCH
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2014
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IF 5.323
Jingu Shi,Zhihui Ai,Lizhi Zhang
In this study we demonstrate Fe@Fe 2 O 3 core–shell nanowires can improve Fenton oxidation efficiency by two times with rhodamine B as a model pollutant at pH > 4. Active species trapping experiments revealed that the rhodamine B oxidation enhancement was attributed to molecular oxygen activation induced by Fe@Fe 2 O 3 core–shell nanowires. The molecular oxygen activation process could generate superoxide radicals to assist iron core for the reduction of ferric ions to accelerate the Fe(III)/Fe(II) cycles, which favored the H 2 O 2 decomposition to produce more hydroxyl radicals for the rhodamine B oxidation. The combination of Fe@Fe 2 O 3 core–shell nanowires and ferrous ions (Fe@Fe 2 O 3 /Fe 2+ ) offered a superior Fenton catalyst to decompose H 2 O 2 for producing OH. We employed benzoic acid as a probe reagent to check the generation of OH and found the OH generation rate of Fe@Fe 2 O 3 /Fe 2+ was 2–4 orders of magnitude larger than those of commonly used iron based Fenton catalysts and 38 times that of Fe 2+ . The reusability and the stability of Fe@Fe 2 O 3 core–shell nanowires were studied. Total organic carbon and ion chromatography analyses revealed the mineralization of rhodamine B and the releasing of nitrate ions. Gas chromatograph-mass spectrometry was used to investigate the degradation intermediates to propose the possible rhodamine B Fenton oxidation pathway in the presence of Fe@Fe 2 O 3 nanowires. This study not only provides a new Fenton oxidation system for pollutant control, but also widen the application of molecular oxygen activation induced by nanoscale zero valent iron .
研究领域:
环境科学
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材料科学
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DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 66
·38891-38896
·
IF 3.049
Qiaohong Zhang,Honghao He,Huibin Wang,Zhan Zhang,Chen Chen
A series of N-alkyl pyridinium salts were synthesized and employed as metal-free catalyst for the selective oxidation of methyl aromatic hydrocarbon with molecular oxygen. The electronic effect of the substitutes was found to be an important factor for the catalytic performance. With the introduction of electron-donating substitute –N(CH3)2, the conversion of p-xylene and selectivity of p-toluic acid could be simultaneously increased. 1-Benzyl-4-N,N-dimethylaminopyridinium salt showed the highest catalytic activity, and 95% conversion with 84% of selectivity to p-toluic acid could be obtained for the selective oxidation of p-xylene. Several methyl aromatic hydrocarbons could all be efficiently oxidized with the reported catalyst at the absence of any metal species.
研究领域:
化学催化
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有机合成
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产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
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2024
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IF 3.9
Dongyang Yang,Bingxiao Feng,Hongxin Wang,Qingjuan Xie,Yaping Liu,Hengjun Gai,Hongbing Song
Selective oxidation of alcohols to aldehydes by molecular oxygen is one of the most important transformations in multiphase catalysis. In this paper, a catalyst with selective oxidation ability was designed and synthesized for the selective catalytic oxidation of benzyl alcohol. N-doped carbon materials were prepared by high-temperature calcination using hydrothermal reaction products of citric acid and melamine as a carbon source, and a bimetallic catalyst supported by Ru-CeO 2 was constructed using the mixture as the carrier for the selective oxidation of benzyl alcohol to benzaldehyde. The results showed that the introduction of CeO 2 could effectively improve the oxidizing ability and catalytic activity of the catalyst. The Ru-Ce 0.05 /NC170–600 catalyst was able to convert 85.5 % benzyl alcohol into benzaldehyde at 140 °C, 6 h, and 2 MPa, and the selectivity for benzaldehyde was 100 %. It was demonstrated by DFT that it was theoretically feasible to generate benzaldehyde by extracting hydrogen atoms from benzyl alcohol molecules. Further, the selective oxidation experiments on other alcohols showed that the catalyst has high activity for the oxidation of various alcohols to generate the corresponding carbonyl products, and it is a catalyst with broad-spectrum selective oxidation ability. In this study, a green synthesis route of benzaldehyde was proposed to solve the problems in the traditional process. Meanwhile, it provides a new idea for the synthesis of carbonyl products by selective oxidation of alcohols.
研究领域:
化学工程
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催化材料科学
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产品关联
DOI
高影响因子
SYNTHETIC COMMUNICATIONS
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2016
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IF 1.065
Shu Guo,Renyou Zeng,Caiye Li
Using novel nitrite-containing resin as an NO source and Amberlyst-15 as cocatalyst, we developed aerobic oxidation of oximes to corresponding carbonyl compounds with molecular oxygen as a clean oxidant reagent. It was distinguished from the previous related reports, and the experimental results indicated that additional water obviously decreased the yield. This process provides a better choice for oxidative deoximation with many advantages, such as high yield, simple procedure, high catalytic performance, and recyclable catalyst.
研究领域:
有机化学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子