JOURNAL OF CATALYSIS
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2024
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IF 6.5
Cheng Liu,Huiling Chen,Qi Chen,Jinhong Bi,Jimmy C. Yu,Ling Wu
A series of Al 3+ -doped UiO-66(Ce) MOFs (U(Ce x Al 1−x )) was developed to reveal the roles of metal doping on active site formation and substrate activation in photocatalytic selective transformation of amines to imines. Al 3+ doping induced crystal structure distortion to form coordinately unsaturated metal (Al, Ce) sites as Lewis acid sites to chemisorb and activate benzylamine (BA). In situ FTIR revealed that the Al site with stronger acid strength facilitated BA activation. The activation degree of N–H bonds in BA was evaluated by changes of calculated force constant. The intermediate products were confirmed through time-dependent in situ FTIR. The Al 3+ -doped sample U(Ce 0.90 Al 0.10 ), the optimal catalyst, showed a significantly increased BA conversion (97.6 %) than that (47.5 %) of undoped sample, which was attributed to enough active sites and the optimal charge mobility. Finally, the present study proposes a synergistic photocatalytic mechanism associated with molecular activation to demonstrate selective oxidation pathways at the molecular level.
研究领域:
材料科学
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化学工程
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催化化学
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DOI
高影响因子
Sustainable Energy & Fuels
·
2021
·Vol. 5
·期 16
·4053-4059
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IF 6.367
Xu Zhang,Xiaoman Li,Wanguo Gao,Shijian Luo,Senda Su,Rong Huang,Min Luo
Metal node substitution in metal organic frameworks is an efficient strategy to enhance their photocatalytic properties. Herein, bimetallic CeZr5-MOF UiO-66 photocatalysts were successfully synthesized by partially replacing Zr with Ce for enhancing the photocatalytic N2 reduction reaction (NRR). The rare earth element Ce was introduced into the node of Zr-MOFs (UiO-66) to form CeZr5 clusters, which enhanced the efficiency of photoexcited electron–hole pair separation and charge transfer via the ligand-to-metal charge transfer process (LMCT), thus promoting the photocatalytic nitrogen fixation performance. Photocatalytic properties increase linearly with the increase of Ce content. Higher Ce proportions (>20%) resulted in new MOFs (Ce-BDC-24) with low photocatalytic activity. The bimetallic system showed enhanced photocatalytic activities for N2 reduction, which was 105.9% higher than that of Zr-UiO-66 and reached 200.13 μmol g−1 h−1. Furthermore, the possible energy transfer mechanism was proposed to explain the photo-induced charge transfer process in the bimetallic UiO-66(CeZr5) system.
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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DOI
高影响因子
JOURNAL OF CATALYSIS
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2023
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IF 7.3
Mengya Guo,Feng Wang,Mingwei Zhang,Li Wang,Xiangwen Zhang,Guozhu Li
Encapsulation of clean metal nanoparticles (NPs) into interior of metal–organic framework (MOF) is of great importance to remarkably improve the stability and tune the catalytic performance of metal NPs. Herein, highly dispersed Pt NPs are encapsulated in UiO-66 with different functional groups on linker (UiO-66-X, X = F, H, NH 2 , OH) through enhanced electron attraction of metal precursor by MOF node and proper reduction by H 2 /Ar gas. Compared with traditional impregnation method, the encapsulation method gives well-defined Pt NPs and controllable microenvironment. Detailed characterizations reveal that functional group of the linker can effectively tune the microenvironment and electronic properties of guest Pt NPs. In situ FTIR was utilized to investigate the adsorption capability and strength of reactants on the catalysts. The electron-deficient Pt species and appropriate surface hydrophobicity match well with the reactants, which is responsible for enhanced catalytic hydrogenation activity of C C and nitro groups. The surface hydrophobicity plays a major role in promoting alkyne hydrogenation. This work is devoted to rationalize the relationship between hydrogenation performance and catalyst property of UiO-66 encapsulated Pt NPs, in terms of energy adaptability in electronic state and structure adaptability in surface chemistry. Rational design strategy of Pt-confined-in-MOF composites through molecular level regulation is provided for hydrogenation.
研究领域:
材料科学
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催化化学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Yuchen Cui,Xiaolei Cui,Lubomira Tosheva,Chunzheng Wang,Yongming Chai,Zixi Kang,Qiang Gao,Kun Wang,Zhihan Zhang,Hailing Guo,Daohong Xia,Daofeng Sun
Effective separation of CO 2 from CH 4 is crucial for the purification of natural gas, which requires membrane materials with high permeability, selectivity, and stability of under high pressures. In this work, a high CO 2 -affinity MOF-based nanofiller (P in @NH 2 -UiO-66) was prepared and integrated in polyetherimide (PEI) to prepare mixed matrix membranes (MMMs) for enhanced CO 2 /CH 4 separation capabilities. The P in @NH 2 -UiO-66 nanofiller comprised an in situ-formed polyethyleneimine-NH 2 -UiO-66 composite prepared via a one-pot synthesis. The polyethyleneimine was covalently attached to the H 2 BDC-NH 2 ligand allowing for a stronger integration within the PEI matrix. The polyethyleneimine affects the nucleation of MOF, leading to miniaturization of the MOF particles. The smaller-sized filler is beneficial for improved interaction at the filler-matrix interface. The numerous amino functionalities grafted onto the NH 2 -UiO-66 increased the CO 2 adsorption sites, thereby enhancing the affinity for CO 2 . Owing to the improved interaction, the elevated CO 2 attraction, and the inherent properties of the porous NH 2 -UiO-66, the fabricated MMMs preformed superior in separating CO 2 /CH 4 . The 30-P in @NH 2 -UiO-66-PEI membrane (containing 30 wt% nanofiller) exhibited a CO 2 /CH 4 selectivity of 27.7 and a CO 2 permeability of 2498.9 Barrer. The CO 2 permeability was 21 times greater than that of the pristine PEI membrane, and 4 times higher compared to P@NH 2 -UiO-66 MMM with polyethyleneimine modified MOF filler prepared by a traditional wet impregnation method. Additionally, the novel MMM demonstrates excellent separation stability under conditions that mimic industrial settings, demonstrating its potential application for natural gas purification.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
RARE METALS
·
2024
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IF 9.6
Liu Cheng,Shi Ying-Zhang,Chen Qi,Ye Bing-Hua,Bi Jin-Hong,Yu Jimmy C.,Wu Ling
Defect engineering in metal organic frameworks (MOFs) has captured significant attention in the field of photocatalysis. A series of UiO-66(Ce) (UiO = University of Oslo) MOFs with different contents of missing-linker defects have been developed for the photocatalytic selective oxidation of benzylamine (BA) and thioanisole (TA) under visible light. The introduction of missing-linker defects promotes the formation of unsaturated Ce sites with a high Ce 3+ content. It also generates a high concentration of oxygen vacancies. In situ Fourier transform infrared spectroscopy (FTIR) results revealed that BA and TA molecules were activated on coordinatively unsaturated Ce sites via the H–N···Ce and the C–S···Ce interactions, respectively. Simulated in situ electron paramagnetic resonance (EPR) data indicate that O 2 activation and reduction occur at coordinatively unsaturated Ce 3+ sites to form ·O 2 – . This is accelerated by the Ce 3+ /Ce 4+ redox cycle associated with the photogenerated electrons. The corresponding photogenerated holes are involved in the deprotonation of the activated BA and TA. The most active sample exhibits 98.4% and 95.5% conversion rates for BA and TA oxidation. Mechanisms for the molecular activation are proposed at the molecular level. Graphical abstract
研究领域:
材料科学
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催化化学
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DOI
高影响因子
RSC Advances
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2019
·Vol. 9
·期 65
·37733-37738
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IF 3.049
Yanghe Fu,Jieyu Wu,Rongfei Du,Ke Guo,Rui Ma,Fumin Zhang,Weidong Zhu,Maohong Fan
Defect engineering can be a promising approach to improve the photocatalytic performance of metal–organic frameworks (MOFs). Herein, a series of defective NH2-UiO-66(Zr) materials were synthesized via simply controlling the synthesis temperature, with concentrated HCl as the modulator and then these as-prepared samples were used to systematically investigate the effects of their structural defects on photocatalytic CO2 reduction. Remarkably, these MOFs with defects exhibit significantly enhanced activities in photocatalytic CO2 reduction, compared with the material without defects. The defect engineering creates active binding sites and more open frameworks in the MOF, and thus facilitates the photo-induced charge transfer and restrains the recombination of photo-generated charges efficiently. The current work provides an instructive approach to improve the photocatalytic efficiency by taking advantage of the structural defects in MOFs, and could also inspire more work on the design of advanced defective MOFs.
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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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2019
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IF 8.355
Zhongguo Wang,Lian Song,Yaquan Wang,Xiong-Fei Zhang,Dandan Hao,Yi Feng,Jianfeng Yao
Composite UiO-66/nanocellulose aerogels with hierarchical pores and low density were prepared through a self-crosslinking method. The nanocellulose acted as the structural skeleton supporting and dispersing the UiO-66 particles. The micropore and accessibility of UiO-66 were well-preserved, making the composite aerogels ideal sorbents for water purification. The composite aerogels demonstrated high adsorption ability towards both anionic methyl orange (71.7 mg g −1 ) and cationic methylene blue (51.8 mg g −1 ). This work holds a promise to rational design and fabrication of MOF monoliths through group linkage.
研究领域:
材料科学
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环境工程
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产品关联
DOI
高影响因子
FUEL
·
2017
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IF 4.601
Xiaotian Zhang,Pengcheng Huang,Aili Liu,Mingyuan Zhu
Owing to the high prices and other shortcomings associated with the existing methods of complex catalyst preparation, we used the UIO-66(Zr) metal–organic frameworks to directly catalyze the oxidative desulfurization (ODS) reaction. The synthesized UIO-66(Zr) was characterized using nitrogen adsorption–desorption isotherm analysis, X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. Under optimal reaction conditions, the ODS conversion of dibenzothiophene (DBT) reached 100%. This excellent catalytic activity was attributed to the unsaturated coordination of Zr, which may produce beneficial Lewis acid sites.
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
ENVIRONMENTAL RESEARCH
·
2025
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IF 7.7
Zhilun Liu,Lei Zhao,Xu He,Shuang Lu,Ding Hou,Jun Ma,Xueyan Li,Fuqiang Guo
In this study, acetic acid (HOAc) was applied to induce missing linker defects on UiO-66 via coordination competition strategy and its role on the outstanding adsorption capacity for ketoprofen (KTP) was investigated systematically. This strategy was proved to simultaneously modulate the defect sites and increase the pore size, pore volume, and surface area of the UiO-66. The missing linker defects constructed porous structure, which dramatically enhanced specific adsorption for KTP. Results showed that the surface area of UiO-66 possessed 27 % enhancement as defect sites increased (from 875.38 to 1439.86 m 2 /g) and exhibited good linearity ( R 2 = 0.998) with adsorption capacity (from 645.5 to 1136.4 mg/g). The adsorption performance of UiO-66 on KTP was investigated on both kinetics and isotherms which were fit by the pseudo-second-order kinetic model and Langmuir model, respectively. According to the Arrhenius equation and Van't Hoff equation, the activation energy increased with missing linker defects and the adsorption is a spontaneous, exothermic and randomness–increasing process. Remarkably, the defective UiO-66 maintained high adsorption resilience across a broad pH range and demonstrated superior selectivity for KTP in the presence of competing ions and humic acid (HA). The results of characterization (FTIR, XPS) and DFT calculations indicated that the adsorption of KTP was primarily driven by chemisorption at the Lewis acid metal centers of UiO-66, accompanied by secondary interactions such as van der Waals forces and hydrogen bonding.
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PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2018
·
IF 3.141
Yan Li,Jiangtao Liu,Kehu Zhang,Lei Lei,Zhongli Lei
A hybrid polymer–MOFs architecture UiO-66-NH2@PMAA was synthesized by tethering polymethacrylic acid (PMAA) onto the surface of the metal–organic frameworks UiO-66-NH2, and it was further employed for pectinase immobilization by electrostatic interactions. The hybrid architecture was prepared through a combination of atom transfer radical polymerization (ATRP), click chemistry and postsynthetic modification (PSM). The optimal immobilization parameters were at 25 °C and pH 4.0 with 10 U/mL of pectinase for 2 h, under which pectinase showed the highest enzymatic activity (1.215 U/mg) and protein loading (448.5 mg/g), respectively. Compared with free pectinase, the immobilized was found to exhibit higher pH, thermo, and storage stability. Additionally, the immobilized pectinase had remarkable reusability, the residual activity reached as high as 81% after 8 cycles continuously. Meanwhile, the desorption of immobilized pectinase can be achieved by changing pH values of the medium. Obviously, the UiO-66-NH2@PMAA with attractive properties is highly promising for enzyme immobilization.
研究领域:
生物化学
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材料科学
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DOI
高影响因子
CELLULOSE
·
2019
·Vol. 26
·期 5
·3387-3399
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IF 3.917
Zhang Chuanjie,Tian Jiaxin,Rao Weida,Guo Bin,Fan Lingling,Xu Weilin,Xu Jie
Metal-organic frameworks (MOFs) are recently attracting more and more interests as supercapacitor electrode materials. However, their low conductivity largely thwarts their capacitance performance. Herein, fabric electrodes for flexible supercapacitors were successfully fabricated by depositing polypyrrole (PPy) nanotubes and Zr-based MOF (UiO-66) particles on cotton fabrics. The PPy nanotubes could serve as conductive connectors to bridge the UIO-66 particles due to their superior conductivity with one-dimensional structure. The conductivity of the PPy@UIO-66@cotton fabric electrode was increased to 14.29 S cm −1 . A specific capacitance of 565 F g −1 at a current density of 0.8 mA cm −2 was obtained for the PPy@UIO-66@cotton fabric electrode. In addition, the proposed fabric electrode exhibited good cycling stability with capacitance retention of 90% after 500 charge–discharge cycles and excellent rate capability. This study confirmed the combination of MOFs and PPy nanotubes has great application prospect in fabric-based flexible supercapacitors.
研究领域:
材料科学
·
能源存储
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产品关联
DOI
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2014
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IF 2.063
Yan Cao,Yunxia Zhao,Zijian Lv,Fujiao Song,Qin Zhong
New composites of UiO-66 and graphene oxide (GO) were synthesized and tested as CO 2 adsorbents at room temperature. The materials and the parent composite components were characterized using X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), nitrogen adsorption–desorption isotherm analysis, scanning electron microscopy (SEM), and FT-IR spectroscopy. The CO 2 isotherms on the UiO-66/GO composites and the UiO-66 were measured by a static volumetric method separately. Experiments of multiple adsorption/desorption cycles were conducted to estimate reversibility of CO 2 on the UiO-66/GO. The results showed that the BET surface area of the composites was higher than that of the parent UiO-66, and the adsorption capacities of CO 2 on the composites were greatly higher than that on the UiO-66 sample. The composite UiO-66/GO-5 exhibited the maximum CO 2 uptake of 3.37 mmol/g at 298 K and 1 bar, which increased by 48% in comparison with that of the UiO-66, and was much higher than those of the conventional activated carbons and the zeolites. The CO 2 adsorption capacity was dependent on the BET surface area and the micropore volume of the composites. Finally, the adsorption/desorption cycle experiment revealed that the adsorption performance of UiO-66/GO-5 was fairly stable, without noticeable degradation in the adsorption capacity of CO 2 after 6 cycles. Therefore, this kind of composites has a potential application on CO 2 capture technologies to mitigate global warming.
研究领域:
材料科学
·
环境科学
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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）