RSC Advances
·
2017
·Vol. 7
·期 61
·38691-38698
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IF 3.108
Bin Li,Wubin Wu,Tianyong Zhang,Shuang Jiang,Xingwei Chen,Guanghui Zhang,Xia Zhang
UiO-66 with high dispersibility and a cuboctahedron morphology was synthesized by an improved solvothermal method. The morphology of UiO-66 was adjusted using benzoic acid as a modulator. UiO-66 with a regular morphology was then used as the support to load ferrocene (Fc). A series of Fc@UiO-66 composites were prepared via a facile impregnation method. The composites were characterized by powder X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), SEM/EDX mapping, FT-IR, UV/vis, TG analysis, N2 adsorption–desorption, and X-ray photoelectron spectroscopy (XPS). The results showed that Fc was incorporated into UiO-66, thus preventing the agglomeration of Fc particles in water. The Fc@UiO-66 composites with a Fc loading of 5% (FU-5) exhibited the highest catalytic activity for hydroxylation of phenol with H2O2 at room temperature in water, which gave a phenol conversion of 38.5% and 87.4% selectivity for dihydroxybenzenes (DHB). UiO-66 played a crucial role in the enhancement of catalytic performance compared with conventional supports such as γ-Al2O3, etc. A hydroxyl radical mechanism was proposed for this catalytic hydroxylation process and the high selectivity was attributed to the interaction between Fc particles and UiO-66.
研究领域:
化学
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催化材料科学
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DOI
高影响因子
OPTICAL MATERIALS
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2024
·
IF 3.8
Yixiong Wu,Yanqi Xu,Cunjun Li,Hai Wang,Xinyu Wang,Aimiao Qin,Haiqing Qin,Linjiang Wang
One-step selectively photocatalytic phenol hydroxylation to produce Dihydroxybenzenes (DHB) is an attractive and challenging strategy. However, the rapid recombination of photogenerated carriers existed in single component photocatalyst seriously hinders the photocatalytic efficiency. The heterojunction strategy can optimize the band structure of the photocatalyst, and effectively improve the carriers' separation and transfer during the photocatalytic process. Herein, we successfully designed and prepared a 3D TiO 2 @Ni 3 Fe 1 -LDH core-shell heterostructure photocatalyst by coupling TiO 2 nanorods with Ni 3 Fe 1 -LDH nanosheets for the photocatalytic phenol hydroxylation to produce DHB. The results showed that the 3D TiO 2 @Ni 3 Fe 1 -LDH core-shell heterostructure had a suitable energy band structure for the photocatalytic phenol hydroxylation and the heterostructure accelerated the carriers’ separation and transfer. Meanwhile, the high porosity and abundant active sites were conducive to the adsorption of H 2 O 2 and the photogenerated carriers transfer efficiency from the photocatalyst to H 2 O 2 . The 3D TiO 2 @Ni 3 Fe 1 -LDH core-shell heterostructure showed excellent photocatalytic performance of phenol hydroxylation, where the phenol conversion was 48.6%, and the selectivity of DHB was 81.1% at 25 °C and 4 h of light illumination. Furthermore, the as-prepared photocatalysts exhibited good stability after four cycles of experiment. This work provided a convenient and efficient method for the green synthesis of DHB.
研究领域:
材料科学
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环境科学
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化学工程
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产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Hang Li,Yi Zhai,Xubin Zhang,Guojun Lv,Yu Shen,Xuqing Wang,Tao Jiang,Yuzhou Wu
Hierarchical iron-containing TS-1 zeolites (FTS) were successfully synthesized via post-treatment desilication over microporous Fe-TS-1, which were prepared through a one-step hydrothermal synthesis. The prepared samples were characterized by X-ray diffraction, N2 adsorption–desorption, field-emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, ultraviolet visible spectroscopy, and X-ray fluorescence spectrometry. The experimental results illustrated that the MFI structure of all the FTS samples remained unchanged after NaOH desilication and acid treatment. The newly created mesopores can be controlled by changing the amount of framework Fe, as the extraction of Si could be affected because of the inhibitory effect of iron species during the desilication process. The catalytic performance of the prepared samples in phenol hydroxylation with H2O2 was investigated. Among all the samples, FTS-50-D showed a highest phenol conversion of 45.2% and a dihydroxybenzene selectivity of 95.2%. Besides, FTS-50-D also showed good reusability for five recycling tests.
研究领域:
材料科学
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催化化学
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产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 79
·76064-76074
·
IF 3.289
Saifu Long,Shijian Zhou,Fu Yang,Kangchao Lu,Tao Xi,Yan Kong
Surface exposed catalytic active species are thought to be responsible for overall catalytic activity and selectivity. In this paper, controllable contents of iron oxides were in situ introduced into the inner surface of anionic surfactant-templated mesoporous silica (AMS) by the metal-modified anionic surfactant templating route, in which anionic micelles decorated with different amounts of Fe2+ were direct utilized to assemble with organosilicate. The characterization results demonstrated that, after thermal treatments, Fe2O3 species were in situ formed and highly-dispersed in the channels of AMS, and the pore size was accordingly tailored to the microporous level (<2 nm). In each AMS catalyst, Fe2O3 showed better dispersion and stability compared with the post-impregnated method. Moreover, the catalytic performances of phenol hydroxylation on the as-synthesized catalysts were significantly enhanced, and the optimal catalyst (Fe/Si = 3.5 wt%) gave a phenol conversion of 44.3% with a selectivity of 82.6% to dihydroxybenzene. By comparison with some reference mesoporous silica catalysts (0.15Fe/MCM-41 and 0.15Fe/SBA-15), the iron-based micropore-enriched silica catalyst (Fe/AMS) gave an obviously higher selectivity to dihydroxybenzene. Finally, the optimal catalyst was examined for at least 5 runs in phenol hydroxylation.
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
Journal of Chemistry
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2021
·
IF 2.506
Renjie Zhou,Gui Chen,Yuejun Ouyang,Hairui Ni,Nonglin Zhou,Bailin Xiang
Using MOF-5 as a template, the porous carbon (MDPC-600) possessing high specific surface area was obtained after carbonization and acid washing. After MDPC-600 was loaded with Cu ions, the catalyst Cu/MDPC-600 was acquired by heat treatment under nitrogen atmosphere. The catalyst was characterized by X-ray powder diffraction (XRD), N2 physical adsorption (BET), field emission electron microscope (SEM), energy spectrum, and transmission electron microscope (TEM). The results show that the Cu/MDPC-600 catalyst prepared by using MOF-5 as the template has a very high specific surface area, and Cu is uniformly supported on the carrier. The catalytic hydrogen peroxide oxidation reaction of phenol hydroxylation was investigated and exhibits better catalytic activity and stability in the phenol hydroxylation reaction. The catalytic effect was best when the reaction temperature was 80°C, the reaction time was 2 h, and the amount of catalyst was 0.05 g. The conversion rate of phenol was 47.6%; the yield and selectivity of catechol were 37.8% and 79.4%, respectively. The activity of the catalyst changes little after three cycles of use.
研究领域:
材料科学
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催化化学
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产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2021
·
IF 5.455
Qing Zhang,Yi Zhai,Fumin Wang,Xubin Zhang,Guojun Lv,Yongkui Liu,Mengyue Li,Mengyao Li
Hierarchical Fe-doped MFI/MCM-41 composites (Fe-HMZs) were one-pot hydrothermal synthesized by partial transformation strategy using conventional CTAB as a dual-functional template. The hierarchical Fe-doped MFI/MCM-41 composites possess ordered mesopores and crystallized MFI structure. The effect of addition amount of NaOH and CTAB as well as the type of the alkali source on the formation of hierarchical Fe-MFI/MCM-41 composites have been investigated in detail. In addition, the temperature-gradient treatment plays the vital roles in the formation of MFI and the possible formation mechanism has been proposed. The obtained hierarchical Fe-HMZ-40 sample exhibits outstanding catalytic performance for phenol hydroxylation and 48% of phenol conversion as well as 89% of dihydroxybenzene selectivity could be achieved, which are ascribed to the more accessible active sites endowed by the significant diffusion ability of ordered mesopores. Compared with Fe-MCM-41 sample, the hydrothermal stability is improved because of the presence of MFI structure.
研究领域:
材料科学
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催化化学
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产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
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2017
·Vol. 93
·期 5
·1347-1358
·
IF 3.135
Yu Shen,Fumin Wang,Zongzhuang Han,Xubin Zhang
BACKGROUND ZSM-5 zeolites are of great importance in industrial catalysis. However, the diffusion limitations caused by small pore opening restrict the extent of catalytic conversions over conventional ZSM-5. Many studies have shown that mass transfer in zeolite channels can be improved by controlling the morphology or creating additional mesoporosity. Here, the catalytic performance is further improved by the creation of hollow structure and intracrystalline mesopores in ZSM-5 zeolite. RESULTS The characterization results demonstrated that hollow ZSM-5 with intracrystalline mesopores can be synthesized by using a simple one-step hydrothermal strategy with a commercial gemini-type cationic surfactant containing hydrophilic hydroxyl groups. Compared with the Fe-substituted conventional ZSM-5, the Fe-substituted hollow ZSM-5 with intracrystalline mesopores show remarkably enhanced catalytic performance in the hydroxylation of phenol. About 52.2% conversion of phenol can be obtained with almost 96.8% selectivity to dihydroxybenzenes. The catalytic activity remained almost unchanged after five cycles. CONCLUSION The newly created hollow structure and intracrystalline mesopores in ZSM-5 zeolite showed enhanced catalytic activity and reusability for the hydroxylation of phenol, which is higher than most reported systems. The prepared catalyst is a promising alternative material for the hydroxylation of phenol. © 2017 Society of Chemical Industry
研究领域:
材料科学
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催化化学
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产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2016
·
IF 3.349
Jing Xu,Abdul-Rauf Ibrahim,Xiaohui Hu,Yanzhen Hong,Yuzhong Su,Hongtao Wang,Jun Li
Alumina was synthesized from Al(NO 3 ) 3 , AlCl 3 and Al 3 (SO 4 ) 2 with NaOH, and from NaAlO 2 with HNO 3 by addition of acidic solution to alkaline solution with a syringe pump. The as-produced Al 2 O 3 precursors were supercritically dried and calcined at 500 °C to obtain mesoporous γ-alumina material. Results showed that all the inorganic aluminum salts could be used to synthesize high pore volume γ-alumina by controlling the precursor addition rate at room temperature and supercritical CO 2 drying. However, the γ-alumina with the largest pore volume (5.4 cm 3 /g), BET surface area (423.7 m 2 /g) and pore size (37.8 nm) was obtained using Al(NO 3 ) 3 and NaOH. This γ-alumina was further used as a support for Fe-based catalyst with hydrogen peroxide to produce hydroquinone and catechol in the phenol hydroxylation reaction in 30 min at 80 °C. The conversion of phenol was 53.4% whereas the selectivity to dihydroxybenzenes-DHBs (hydroquinone-HQ and catechol-CAT) was as high as 96.2%, revealing that the larger pore volume takes effect in the γ-alumina as support for the Fe-based catalyst in the hydroxylation reaction, and that the γ-alumina may be a good candidate as the support for other important catalysts such as those used in the petroleum refining industry.
研究领域:
化学工程
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催化材料
✓ 已验证
DOI
高影响因子
Small Methods
·
2024
·
IF 10.7
Yanling Wang,Yanqi Xu,Cunjun Li,Hai Wang,Linjiang Wang
The super-stable mineralization of metal ions from industrial wastewater by in situ synthesis of layered double hydroxides (LDHs) has been regarded as a sustainable approach from environmental protection and resource utilization perspectives. Herein, the study reports a super-stable mineralization of metal ions including Ni, Fe, Cr, Mn, Cu, Ca, Al, etc. from smelting wastewater by in situ synthesis of NiFe-based LDHs through facile coprecipitation. Such approach exhibits superior mineralization efficiency of metal ions simultaneously that can remove hundreds, thousands, or even tens of thousands mg/L of multiple metal ions to below the values of the Chinese National Emission Standards of Pollutants. Furthermore, the obtained NiFe-based LDHs exhibit excellent catalytic performance of phenol hydroxylation due to the mineralization of multiple metals on the laminates, where 48.24% conversion of phenol and 71.58% selectivity of dihydroxybenzenes are realized under room temperature for 3 h. This work paves a sustainable strategy for hazardous material disposal and resource utilization.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Rui Feng,Zhou Fang,Wei Wang,Tianbo Li,Xiaoyan Hu,Xinlong Yan,Zhongdong Zhang
Direct hydroxylation of benzene to phenol is an environmentally friendly strategy to produce phenol compared with the conventional process. In this work, vanadium-modified titanium silicate-1 (TS-1) with enhanced Lewis acid and charge density were prepared as catalysts for efficient hydroxylation of benzene to phenol in the presence of hydrogen peroxide as an oxidant under mild conditions. The hierarchical TS-1 zeolites with a high framework Ti content were synthesized in the presence of NH4HCO3, and then vanadium doping was used to change the acidity and charge density. It was found that NH4HCO3 favored the titanium substitution of framework sites and nanocrystal stacking of TS-1. Vanadium doping increased the amount of Lewis acid sites and the charge density associated with the framework Ti. The enhancement in acid and electron characteristics boosted the intrinsic catalytic reactivity of Ti-OOH species, which further improved the performances toward benzene hydroxylation. The presented strategy and mechanistic results clarified the relationship between the structure and acidity in TS-1 zeolite. It was also verified that hydroxyl radicals (•OH) rather than superoxide radicals (•O2–) were the reactive agents responsible for the consecutive selective oxidation of benzene.
研究领域:
催化化学
·
环境科学
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产品关联
DOI
高影响因子
JOURNAL OF POROUS MATERIALS
·
2018
·Vol. 25
·期 6
·1587-1595
·
IF 1.858
Shen Yu,Wang Fumin,Liu Wei,Zhang Xubin
A series of Fe 3+ containing catalysts were synthesized using ion-exchange technique over hierarchically porous ZSM-5 (M-ZSM-5) and micro-mesoporous composite ZSM-5/MCM-41 (ZSM-5/MCM-41), respectively. The prepared catalysts were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, N 2 adsorption–desorption, UV–Vis spectroscopy, temperature programmed reduction and inductively coupled plasma-optical emission spectroscopy. The characterization results exhibit that the hierarchically porous ZSM-5 was synthesized with intracrystalline mesopores, while the micro-mesoporous composite ZSM-5/MCM-41 was prepared with the well-ordered mesopores. Furthermore, the results also prove that the existence of iron in the catalysts was mainly presented in the form of Fe 3+ ions. Catalytic performances of the samples for phenol hydroxylation were compared by using H 2 O 2 as oxidant. Under the optimized conditions, Fe 3+ ion-exchanged M-ZSM-5 (Fe-M-ZSM-5) shows that a phenol conversion of 42.3% obtained with 92.5% selectivity to dihydroxybenzenes, whereas Fe 3+ ion-exchanged ZSM-5/MCM-41 (Fe-ZSM-5/MCM-41) give 46.2% phenol conversion and 90.1% dihydroxybenzenes selectivity, which are all better than most reported results. The recyclability tests show that Fe-ZSM-5/MCM-41 with ordered mesoporous structure and bigger surface area has better anti-deactivation performance than Fe-M-ZSM-5. The excellent catalytic performances were due to the improved diffusion performance with newly created mesopores and the highly active Fe 3+ species obtained by ion-exchange technique.
研究领域:
材料科学
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催化化学
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产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2022
·
IF 5.876
Yi Zuo,Yu Chen,Tonghui Li,Jiaojiao Yu,Hong Yang,Min Liu,Xinwen Guo
A bulky composite material, CaCO 3 @TS-1, was synthesized in a tetrapropylammonium bromide hydrothermal system by adding nanosized CaCO 3 particles of 60–80 nm to a titanium silicalite-1 (TS-1) synthesis gel. The macroporous TS-1 free of extraframework Ti was then obtained by the posttreatment of the CaCO 3 @TS-1 in HCl solution to remove CaCO 3 and extraframework Ti simultaneously. This study demonstrates that this new synthesis route, the acidity posttreatment, can produce a bulky TS-1 with volume-controllable intracrystal macropores. The crystallization mechanism of the macroporous TS-1 was studied systematically. The addition of CaCO 3 accelerates the crystallization of silicon source, and leads to the similar crystallization rates of silicon and titanium sources. Therefore, the formation of extraframework Ti was inhibited, and more Ti ions were inserted into the TS-1 framework. The catalytic performance of macroporous TS-1 was evaluated in the hydroxylation of phenol . An outstanding catalytic activity was obtained due to their enhanced diffusion property and reduced extraframework Ti.
研究领域:
材料科学
·
催化化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）