CHINESE JOURNAL OF CATALYSIS
·
2016
·
IF 2.628
Jianqiang Zhang,Yongsheng Peng,Wenguang Leng,Yanan Gao,Feifei Xu,Jinling Chai
We introduced bipyridine ligands into a series of two-dimensional (2D) covalent organic frameworks (COFs) using 2,2′-bipyridine-5,5′-dicarbaldehyde (2,2′-BPyDCA) as a component in the mixed building blocks. The framework of the COFs was formed by the linkage of imine groups. The ligand content in the COFs was synthetically tuned by the content of 2,2′-BPyDCA, and thus the amount of metal, palladium(II) acetate, bonded to the nitrogen ligands could be manipulated. Both the bipyridine ligands and imine groups can coordinate with Pd(II) ions, but the loading position can be varied, with one ligand favoring binding in the space between adjacent COFs′ layers and the other ligand favoring binding within the pores of the COFs. The Pd(II)-loaded COFs exhibited good catalytic activity for the Heck reaction.
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RSC Advances
·
2016
·Vol. 6
·期 74
·69909-69918
·
IF 3.289
Wentong Song,Shengyang Tao,Yongxian Yu,Xuanlu Du,Shuo Wang
This article reports a facile synthetic approach for preparing magnetic porous catalysts, on which various inorganic compounds are alternately loaded using a pyrogallic acid (PG)-assisted layer-by-layer (LbL) coating. The PG forms an adhesion and reductive layer on the surface of hierarchically porous silica, and Pd, Al2O3, ZrO2, or FeOx can then be introduced on the surface of the material. Compared with the conventional impregnation method, the PG layer obviously improves the dispersion of catalysts and greatly reduces the blocking of the pores, which is caused by the formation of metal oxide catalysts. At the same time, the reduction properties of the layer help to reduce the diameter of the Pd nanoparticles to 5 ± 1.3 nm. The Fe3+ ions are partially reduced into Fe2+ by the PG layer to form Fe3O4, which endows the porous catalysts with a magnetic separation property. The synthesized multicomponent catalysts show excellent catalytic activity for various reactions, including the Suzuki Miyaura coupling, reduction, Knoevenagel condensation and Friedel–Crafts alkylation reactions. The TOF values show an improvement of 2 to 4 times over those of the catalysts prepared by the traditional impregnation method. The multicomponent magnetic catalysts also exhibit superior catalytic performance for many one-pot multistep cascade reactions.
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APPLIED SURFACE SCIENCE
·
2016
·
IF 3.15
Guangjian Zeng,Meiying Liu,Kexin Shi,Chunning Heng,Liucheng Mao,Qing Wan,Hongye Huang,Fengjie Deng,Xiaoyong Zhang,Yen Wei
Surface modification of nanodiamond (ND) with poly(2-methacryloyloxyethyl phosphorylcholine) [poly(MPC)] has been achieved by using metal free surface initiated atom transfer radical polymerization (SI-ATRP). The ATRP initiator was first immobilized on the surface of ND through direct esterification reaction between hydroxyl group of ND and 2-bromoisobutyryl bromide. The initiator could be employed to obtain ND-poly(MPC) nanocomposites through SI-ATRP using an organic catalyst. The final functional materials were characterized by 1 H nuclear magnetic resonance, transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and thermo gravimetric analysis in detailed. All of these characterization results demonstrated that ND-poly(MPC) have been successfully obtained via metal free photo-initiated SI-ATRP. The ND-poly(MPC) nanocomposites shown enhanced dispersibility in various solvents as well as excellent biocompatibility. As compared with traditional ATRP, the metal free ATRP is rather simple and effective. More importantly, this preparation method avoided the negative influence of metal catalysts. Therefore, the method described in this work should be a promising strategy for fabrication of polymeric nanocomposites with great potential for different applications especially in biomedical fields.
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ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Qinrui Fu,Yuan Meng,Zilin Fang,Quanqin Hu,Liang Xu,Wenhua Gao,Xiaochun Huang,Qiao Xue,Ya-Ping Sun,Fushen Lu
Boron nitride nanosheets (BNNS) were used to anchor bimetallic Pd–Fe nanoparticles for Suzuki–Miyaura coupling catalysts. The bimetallic nanoparticles were found to be core–shell in structure, and their formation was likely facilitated by their interactions with the BNNS. The Pd–Fe/BNNS catalysts were highly effective in representative Suzuki–Miyaura reactions, with performances matching or exceeding those of the state-of-the-art methods. Specifically, the superior catalytic activities were characterized by generally shortened reaction times, minimal Pd usage, excellent reusability of the catalysts and high or nearly quantitative conversion yields in a benign solvent system without the need for any special conditions, such as ligands and surfactants or inert gas protection. The obvious advantages of the Pd–Fe/BNNS over similar catalysts based on other supports, such as reduced graphene oxide (rGO), suggest that BNNS may be developed into a versatile platform for many other important catalytic reactions.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Jiayin Gao,Yaoyao Wang,Yuqing Yu,Mengxiang Zhu,Wen Kong,Genyan Liu,Xiaogang Luo
Catalytic reduction of p -nitrophenol is usually carried out using transition metal nanoparticles such as gold, palladium , silver , and copper, especially palladium nanoparticles (Pd NPs), which are characterized by fast reaction rate, high turnover frequency , good selectivity, and high yield. However, the aggregation and precipitation of the metals lead to the decomposition of the catalyst, which results in a significant reduction of the catalytic activity. Therefore, the preparation of homogeneous stabilized palladium nanoparticles catalysts has been widely studied. Stabilized palladium nanoparticles mainly use synthetic polymers . Cellulose microspheres , as a natural polymer material with low-cost and porous fiber network structure, are excellent carriers for stabilizing metal nanoparticles . Cellulose microspheres impregnated with palladium metal nanoparticles were carbonized to have a larger specific surface area and highly dispersed palladium nanoparticles, which exhibited excellent catalytic activity in the catalytic reduction of p -nitrophenol. In this work, the cellulose carbon-based microspheres palladium (Pd@CCM) catalysts were designed and characterized by SEM, TEM , EDS, XRD, FTIR, XPS , TGA , BET, and so on. Furthermore, the catalytic performance of Pd@CCM catalysts was investigated via p -nitrophenol reduction, which showed high catalytic activity. This catalyst also exhibited excellent catalytic performance in the Suzuki-Miyaura coupling reaction. Linking aromatic monomer and benzene through Suzuki-Miyaura coupling was presented as an effective route to obtaining biaryls , and the synthesis method is low-cost and simple. In addition, Pd@CCM showed desirable recyclability while maintaining its catalytic activity even after five recycles. This work is highly suggestive of the design and application of the heterogeneous catalyst .
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Journal of Materials Chemistry B
·
2017
·Vol. 5
·期 43
·8525-8531
·
IF 4.543
Hengchang Ma,Manyi Yang,Caili Zhang,Yucheng Ma,Yanfang Qin,Ziqiang Lei,Lu Chang,Lei Lei,Tao Wang,Yuan Yang
Aggregation-induced emission (AIE)-active compounds are attractive fluorescent materials for applications in chemical and biological sensing. The AIE effect of such materials amplifies changes in the fluorescence signal due to the physical state transformation from aggregation to disaggregation, which can be employed for detecting various analytes with high sensitivity. In particular, specific bio-active analyte recognition is not only very interesting but also challenging. In this paper, we report a set of novel AIE-active fluorescent probes containing pyridiniums and boric acid groups (TPA-PP, TPA-PPA-1, TPA-PPA-2, TPA-PPA-3), which has been developed for adenosine 5′-triphosphate (ATP) recognition. These probes with two types of interaction modes and multiple connection sites toward ATP molecules are able to selectively discriminate ATP among other bioactive anions with a significant enhancement in fluorescence emission. In particular, in the application of cell imaging, as the number of positive charges and boric acid group increased further, the probes could penetrate into cells, and then enter into the nucleus very specifically. These results clearly demonstrate that the newly developed sensors are suitable for specific tracing of different cell organelles with a height visualization and retention ability. Therefore, all of them are confirmed as promising alternatives for live cell imaging in the future.
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Catalysis Science & Technology
·
2018
·Vol. 8
·期 5
·1423-1434
·
IF 5.365
Rui Yu,Rui Liu,Jie Deng,Maofei Ran,Ning Wang,Wei Chu,Zhiwei He,Zheng Du,Chengfa Jiang,Wenjing Sun
Pd nanoparticles (NPs) supported on polyaniline (PANI)-coated carbon nanotubes (CNTs) were synthesized using a low-cost and simple method for application in the Heck reaction. The effects of the PANI/CNT coating weight ratio on the catalytic stability and recyclability of the composite were determined by using a combination of experimental and computational methods. The results show that through coordination of the N-species in PANI with the Pd NPs, the nitrogen-rich PANI@CNT provides a strong support for the Pd NPs. The thickness of the PANI layer is the key in determining the stability of the catalyst. PANI becomes protonated in the presence of CNTs, as electron transfer from the former to the latter creates strong interactions between the two. Thus, PANI becomes more stable in nanocomposites with a higher CNT content, e.g., PANI/CNT = 0.5 : 1. The catalyst with a PANI/CNT ratio of 0.5 : 1 exhibited the best recycling performance, and only a small loss of activity was observed after 10 cycles. However, upon increasing the PANI content (e.g., PANI/CNT = 4 : 1), the PANI units tend to form bulk structures that are less stable than those that wrap around the CNTs. Such a structure is unstable; therefore, the PANI layers can easily deform or break away from the CNT backbones. Hence, these catalysts deactivate during recycling. Thus, our study demonstrates that the assembly of noble-metal NPs on CNTs bearing a thin coaxial PANI coating is a powerful technique to prepare reusable catalysts for the Heck reaction. Coating thickness is also a key factor affecting the efficiency and stability of the catalyst.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Hongwei He,Zhoulin Ma,Shuya Zhang,An Cai,Huan Ye,Xiaobin Fan,Wenchao Peng,Yang Li
A palladium–zinc alloy nanoparticles decorated nitrogen-doped porous carbon catalyst (PdZn 30 –NC) was synthesized and utilized for Suzuki coupling reaction. The alloying palladium (Pd) with zinc (Zn) and pore expanding are realized simultaneously. Density functional theory (DFT) calculations and experimental studies reveal that the alloying Pd with Zn can lower the energy barrier in Suzuki coupling reaction. Nitrogen adsorption–desorption measurements uncover that pore expansion caused by the zinc nitrate hexahydrate assisted calcination gives rise to the multiplication of mesopore with a pore diameter of 6 nm, which facilitates mass transfer during the reaction. As a result, the alloying Pd with Zn and pore expanding together endow PdZn 30 –NC with excellent catalytic activity. PdZn 30 –NC demonstrates exceptional catalytic activity and stability in Suzuki coupling reaction. A high biphenyl yield of 97.7 % within 40 min and stable reusability of 93.3 % yield after five reuse cycles can be achieved. This work not only offers a viable method for Suzuki coupling reaction, but also provides insights for designing new catalysts toward Suzuki coupling reaction.
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REACTIVE & FUNCTIONAL POLYMERS
·
2011
·
IF 2.546
Kan Zhan,Huanhuan You,Wenyu Liu,Jie Lu,Ping Lu,Jian Dong
A novel type of Heck reaction catalyst composed of hydrophilic interpenetrating polymer networks (IPNs) and palladium (Pd) nanoparticles was prepared by simultaneous crosslinking of polyvinyl alcohol and polyacrylamide . The mesh sizes of the IPNs are one order of magnitude smaller than the average sizes of the uniformly dispersed Pd nanoparticles, which functions well to stabilize Pd nanoparticles and prevent aggregation. The Pd particles in the IPNs can catalyze Heck coupling reactions with high activities and be recycled over 20 times, providing more sustainability than any other polymer-stabilized Pd catalyst reported in the literature. The confined reactions inside the IPN nanopores in neat water may provide a green route for C–C coupling reactions.
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CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Zhizi Ma,Meng Yuan,Ziyong Cheng,Zhuang Yang,Ling Yang,Bin Liu,Yulong Bian,Abdulaziz A. Al Kheraif,Ping'an Ma,Jun Lin
Due to the shallow penetration depth of light in biological tissues, the effectiveness of photothermal therapy (PTT) in deep-seated tumors is limited. Conversely, ultrasonic wave has excellent tissue penetration depth. Using ultrasound (US) as an exogenous physical stimulus to trigger tumors thermotherapy is a promising alternative for deep-seated tumors to supersede conventional PTT. Here, we realized a mild sonothermal therapy (STT) using biodegradable red phosphorus nanoparticles (RP NPs) as sonothermal agents. Quite obvious sonothermal conversion of RP NPs is remarkable under low intensity US irradiation, with the temperature rise from 30 to 47 °C at tumor site. In terms of potential mechanism, under US excitation, the internal electrons of RP NPs undergo transition and release the energy by electrons and holes recombination process. This elicits the atom thermal vibration and raises the temperature around the RP NPs. Additionally, US irradiation can stimulate RP NPs to produce singlet oxygen ( 1 O 2 ) and reduce intracellular energy levels that leads to downregulation of the heat shock proteins (HSPs) expression, providing an “escort” to mild STT. This work offers a new paradigm for the strategies of STT enhanced by sonodynamic effect.
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CATALYSIS LETTERS
·
2012
·Vol. 143
·期 2
·200-205
·
IF 2.242
Zeng Yan,Wang Yanhua,Xu Yicheng,Song Ying,Jiang Jingyang,Jin Zilin
Abstract A thermoregulated ionic liquid and organic biphasic system composed of ionic liquid [CH 3 (OCH 2 CH 2 ) 16 N + Et 3 ][CH 3 SO 3
− ] (IL PEG750 ) with IL PEG750 -stabilized Pd nanoparticles and organic solvents, which allows for not only a highly efficient homogeneous catalytic reaction, but also an easy biphasic separation and reuse of catalyst attributed to the thermoregulated phase-transition property of the system, was employed for Heck reaction. The IL PEG750 -stabilized Pd nanoparticle catalyst exhibited high efficiency, more importantly, after reaction the Pd nanoparticle catalyst could be separated from products by simple phase separation and recycled for six times without evident loss of activity. Graphical Abstract A thermoregulated ionic liquid and organic biphasic system containing [CH 3 (OCH 2 CH 2 ) 16 N + Et 3 ][CH 3 SO
- 3
] (IL PEG750 )-stabilized Pd nanoparticles was applied to Heck reaction for the first time. The Pd nanoparticle catalyst exhibited high efficiency and good recyclability.
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ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Yanna Wang,Liguang Dou,Hui Zhang
A series of novel nanosheet array-like catalysts Pdx/rGO@CoAl-LDH (x = 0.0098–1.9, refers to Pd loading in wt % on ICP, rGO: reduced graphene oxide, LDH: layered double hydroxide) were first prepared via a simple and green lattice atomic-confined in situ reduction of oxidative Pd precursors by the evenly atomic-dispersed reductive Co2+ sites on LDH layers of a nanohybrid rGO@CoAl-LDH with hexagonal LDH nanoplates (∼73 × 7 nm) interdigitated vertical to the surfaces of rGO layer in both sides, fabricated through a simple citric acid-assisted aqueous-phase coprecipitation method. The as-obtained Pd catalysts possess clean Pd nanoclusters (NCs) with tunable sizes in 1.3–1.8 nm on varied Pd loadings. All the Pdx/rGO@CoAl-LDH catalysts show excellent activities for the Heck reaction, and the Pd0.0098/rGO@CoAl-LDH with the ultrafine Pd NCs of 1.3 ± 0.2 nm yields a maximum turnover frequency of 160 000 h–1 over a heterogeneous catalyst so far. The excellent activities can be attributed to the ultrasmall Pd NCs with high dispersion and clean Pd surfaces, increased electron transfer capacity and surface area, and remarkable Pd–CoAl-LDH—rGO three-phase synergistic effect of the present unique nanosheet array-like Pd NCs catalysts. Moreover, the catalyst Pd0.33/rGO@CoAl-LDH shows a broad range of substrate applicability and can be reused more than five runs without obvious loss of activity, giving the present catalysts long-term stability. These findings make the rGO@CoAl-LDH hybrid prepared by a facile and scalable synthesis route a universal green platform to support other noble or nonprecious metal NCs via lattice atomic-confined in situ reduction strategy to construct more desired heterogeneous catalysts.
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