CHINESE JOURNAL OF CATALYSIS
·
2016
·
IF 2.628
Zhifeng Dai,Fang Chen,Qi Sun,Yanyan Ji,Liang Wang,Xiangju Meng,Feng-Shou Xiao
An efficient catalyst system based on a Pd-metalated porous organic polymer bearing phenanthroline ligands was designed and synthesized. This catalyst was applied to various C–C bond-forming reactions, including the Suzuki, Heck and Sonogashira couplings, and afforded the corresponding products while exhibiting excellent activities and selectivities. More importantly, this catalyst can be readily recycled. These features show that such catalysts have significant potential applications in the future.
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 83
·79781-79791
·
IF 3.289
Yanmei Luo,Junhui Ran,Rong Chen,Xinjian Cheng
Porous organic polymers (POPs) were prepared via two-step reactions. In the first step, dialdehyde compounds were synthesized using the Suzuki–Miyaura coupling reaction, and in the second step, the dialdehyde compounds reacted with hydrazine hydrate to form polymers using Schiff’s base formation reactions. These POPs are nanosheet-layer structured, crystalline and fluorescent. They were studied using FTIR, fluorescence spectra, UV-Vis, SEM, TEM, XRD, DSC, and TGA. It was found that the pore parameters, such as specific surface areas and pore diameters, of the POPs could be adjusted by changing the reaction time and temperature. The specific surface areas increased with the increasing of reaction time and temperature. The maximum specific surface area could reach 715.6 m2 g−1. Furthermore, the POPs could detect and remove Pd(II) ions and organic dyes. When in contact with Pd(II) ions, the fluorescence of the POPs was quenched, and the POPs could absorb Pd(II) ions as well. The maximum absorption capacity for Pd(II) ions could reach 20.6 mg g−1 within 5 min. Meanwhile, the POPs could absorb two model dyes, rhodamine B (RhB) and methylene blue (MB), with high efficiency within 5 min.
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Tianyu Guo,Jianping Du,Jinting Wu,Shuang Wang,Jinping Li
Lamellar octahedral ceria (LOC) was synthesized by a facile hydrothermal route. The catalyst properties of Pd-supported on the as-synthesized LOC material for low-concentration methane oxidation and reaction kinetics were also investigated. The structure and morphology of samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, nitrogen ad/desorption, X-ray photoelectron spectroscopy and hydrogen temperature-programmed reduction techniques. As-synthesized ceria has octahedral morphology and surface-stepped microstructures, and this unique structural CeO 2 exposes (1 1 0) crystal planes superior to general (1 1 1) facet in catalyst. The results show that LOC-supported Pd catalyst exhibits excellent low-temperature activity and stability by optimizing Pd loadings. The properties are further enhanced by introducing guest metal into the LOC material and the advantage of the Zr-modified LOC-supported Pd catalyst was confirmed by kinetic study. The optimum catalyst maintains high low-temperature activity and stability under various gas hourly space velocities, suggesting it has promising application in complete oxidation of low-concentration methane for different flow rates of ventilation air.
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 75
·47539-47546
·
IF 3.108
Song Zhang,Chao Xu,Guoqing Zhai,Mingliang Zhao,Mo Xian,Yuxiang Jia,Zongjiang Yu,Fusheng Liu,Fangfang Jian,Weizhi Sun
A new type of bimetallic palladium and aluminum incorporated mobile crystalline materials (Pd–Al-MCM-41) as bifunctional catalysts has been hydrothermally synthesized. Characterization shows that these molecular materials exhibit an ordered mesoporous structure, high surface area and a good dispersion of palladium in the frame. The catalytic activity of the Pd–Al-MCM-41 for the dimerization–hydrogenation reaction system of β-pinene in one pot has been systematically studied. Pd0.5–Al30-MCM-41 (SiO2/Al2O3 = 30, 0.5 wt% palladium content) was found to be the best catalyst which gave a dimer yield of up to 64.7%. It is worth noting that palladium shows a good synergic catalytic effect with aluminum in the dimerization reaction and enhances the dimerization yield. Furthermore, the bifunctional catalyst displayed a good activity over 4 runs.
✓ 已验证
产品关联
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2015
·Vol. 116
·期 2
·451-466
·
IF 1.17
Jiang Dahao,Mao Jun,Fang Zheng,Ni Jun,Zhang Qunfeng,Li Xiaonian
In this paper, the deactivation causes of the Pd/SiO 2 catalyst for continuous liquid-phase selective hydrogenation of 6,10,14-trimethylpentadeca-13-en-2-one in 2000 h of pilot plant test were systematically investigated by N 2 adsorption–desorption, thermogravimetric and differential thermal analyses, scanning electron microscope, transmission electron microscope, X-ray diffraction, X-ray fluorescence, experiments of CO poisoning and regeneration, and laboratory retests of the deactivated catalyst samples. The pore textures of Pd/SiO 2 catalysts were not destructed during the pilot test, while there were no obvious carbonaceous deposits appearing on the deactivated catalyst samples. The sintering and crystallization of Pd metal nanoparticles were found, which could be partially accountable for the deactivation of Pd/SiO 2 catalysts. Though Pd leaching did not take place in the pilot test, the Pd active phase could be slightly poisoned by sulfur impurities from feedstock hydrogen. Combining the results of CO poisoning and regeneration experiments with those of compositional analyses of fresh and circulating hydrogen in the pilot test, it could be concluded that CO poisoning should be another important reason for the deactivation of the Pd/SiO 2 catalyst due to high concentration of CO in the reaction system of pilot test and relatively low reaction temperature in the middle and at the bottom of the catalyst bed. Fortunately, the CO poisoned Pd/SiO 2 catalyst in the pilot test could be in situ regenerated by installing a purifier for CO elimination from the circulating hydrogen and increasing the temperature of the whole catalyst bed to slightly higher than 383 K.
✓ 已验证
产品关联
DOI
高影响因子
ULTRASONICS SONOCHEMISTRY
·
2012
·
IF 3.567
Deming Zhao,Min Li,Dexing Zhang,Shams Ali Baig,Xinhua Xu
Palladium/Iron (Pd/Fe) nanoparticles were prepared by using ultrasound strengthened liquid phase reductive method to enhance dispersion and avoid agglomeration. The dechlorination of 2,4-dichlorophenol (2,4-DCP) by Pd/Fe nanoparticles was investigated to understand its feasibility for an in situ remediation of contaminated groundwater. Results showed that 2,4-DCP was first adsorbed by Pd/Fe nanoparticles, then quickly reduced to o-chlorophenol (o-CP), p-chlorophenol (p-CP), and finally to phenol (P). The induction of ultrasound during the preparation of Pd/Fe nanoparticles further enhanced the removal efficiency of 2,4-DCP, as a result, the phenol production rates increased from 65% (in the absence of ultrasonic irradiation) to 91% (in the presence of ultrasonic irradiation) within 2 h. Our data suggested that the dechlorination rate was dependent on various factors including Pd loading percentage over Fe 0 , Pd/Fe nanoparticles availability, temperature, mechanical stirring speed, and initial pH values. Up to 99.2% of 2,4-DCP was removed after 300 min reaction with these conditions: Pd loading percentage over Fe 0 0.3 wt.%, initial 2,4-DCP concentration 20 mg L −1 , Pd/Fe dosage 3 g L −1 , initial pH value 3.0, and reaction temperature 25 °C. The degradation of 2,4-DCP followed pseudo-first-order kinetics reaction and the apparent pseudo-first-order kinetics constant was 0.0468 min −1 .
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2014
·
IF 4.086
Yuxiu Li,Xiangheng Niu,Jie Tang,Minbo Lan,Hongli Zhao
Facilitating the glucose electro-oxidation reaction is always of great scientific sense due to its wide applications in sensing, catalysis and biofuel cells. On the road to improving the electrocatalysis of glucose, one-dimensional materials mainly including nanowires and nanotubes are commonly proposed because of their fascinating characters, and both of them are reported capable of offering better catalytic performance compared to commercial Pt/C and Pt black catalysts. However, so far it still confuses us that which structure can provide more favorable properties towards the direct electro-oxidation of glucose. Here we carry out a systematically comparative study of nonenzymatic electrochemical sensors based on vertical nanowire and nanotube arrays for glucose detection. By using bimetallic Pt-Pd as a general model, we demonstrate that nanotube arrays, owing to their larger catalytic area and higher catalyst utilization, show higher activity for glucose electro-oxidation and enzyme-free analysis than nanowire arrays. These findings may be helpful for the future design of more efficient catalyst structures for glucose oxidation and other reactions.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2013
·
IF 4.675
Shan-Shan Li,Jianyan Yu,Yuan-Yuan Hu,Ai-Jun Wang,Jian-Rong Chen,Jiu-Ju Feng
Shape-controlled synthesis of bimetallic catalysts attracts increasing attention, because their catalytic performance is closely correlated with the size, shape and crystal structure. In this report, a rapid and simple route is developed for large-scale synthesis of Pt–Pd hollow nanospheres (Pt–Pd HNSs) supported on reduced graphene oxide nanosheets (RGOs) under mild conditions, while no surfactant , seed, or template is involved. The as-prepared nanocomposites display the improved electrocatalytic activity and better stability for methanol oxidation in alkaline media , compared with commercial Pt black and Pd black catalysts. This work may open a new route for construction of Pt-based bimetallic catalysts in fuel cells.
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS COMMUNICATIONS
·
2014
·
IF 3.32
Xuanduong Le,Zhengping Dong,Zhicheng Jin,Qingqing Wang,Jiantai Ma
In this study, a novel Pd(II) complex functionalized core–shell magnetic mesoporous catalyst (Fe 3 O 4 @SiO 2 @mSiO 2 –Pd(II)) was synthesized by a simple cost effective procedure. It was characterized by transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, vibrating sample magnetometer, and nitrogen physical adsorption. The Fe 3 O 4 @SiO 2 @mSiO 2 –Pd(II) catalyst offered high surface area and exhibited excellent activity towards Suzuki–Miyaura cross-coupling reaction of halides with aryl boronic acids in ethanol in air. The Fe 3 O 4 @SiO 2 @mSiO 2 –Pd(II) catalyst was stable, reusable, and conveniently recovered by applying an external magnetic field. Moreover, it provided 91% conversion after the sixth catalytic run. The Fe 3 O 4 @SiO 2 @mSiO 2 –Pd(II) catalyst examined in this study combined both the efficiency of a homogeneous catalyst and the durability of a heterogeneous catalyst. The results revealed that the Fe 3 O 4 @SiO 2 @mSiO 2 –Pd(II) catalyst is promising as a candidate for various Pd-based catalytic applications.
✓ 已验证
产品关联
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2014
·
IF 6.451
Xiang Zhu,Xiangheng Niu,Hongli Zhao,Jie Tang,Minbo Lan
Monitoring of reactive oxygen species like superoxide anion (O 2 ∙− ) turns to be of increasing significance considering their potential damages to organism. In the present work, we fabricated a novel O 2 ∙− electrochemical sensor through immobilizing superoxide dismutase (SOD) onto a Pt–Pd/MWCNTs hybrid modified electrode surface . The Pt–Pd/MWCNTs hybrid was synthesized via a facile one-step alcohol-reduction process, and well characterized by transmission electron microscopy , X-ray photoelectron spectroscopy and X-ray diffraction. The immobilization of SOD was accomplished using a simple drop-casting method, and the performance of the assembled enzyme-based sensor for O 2 ∙− detection was systematically investigated by several electrochemcial techniques. Thanks to the specific biocatalysis of SOD towards O 2 ∙− and the Pt–Pd/MWCNTs – promoted fast electron transfer at the fabricated interface, the developed biosensor exhibits a fast, selective and linear amperometric response upon O 2 ∙− in the concentration scope of 40–1550 μM ( R 2 =0.9941), with a sensitivity of 0.601 mA cm −2 mM −1 and a detection limit of 0.71 μM ( S / N =3). In addition, the favorable biocompatibility of this electrode interface endows the prepared biosensor with excellent long-term stability (a sensitivity loss of only 3% over a period of 30 days). It is promising that the proposed sensor will be utilized as an effective tool to quantitatively monitor the dynamic changes of O 2 ∙− in biological systems.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysis Science & Technology
·
2015
·Vol. 5
·期 6
·3333-3339
·
IF 5.426
Dong-Mei Lv,Zhong-Ning Xu,Si-Yan Peng,Zhi-Qiao Wang,Qing-Song Chen,Yumin Chen,Guo-Cong Guo
(Pd–CuCl2)/γ-Al2O3 catalyst with excellent activity and selectivity has been successfully developed for vapor-phase carbonylation of methyl nitrite to dimethyl carbonate (DMC). It has been demonstrated that Cl− is necessary for the superior selectivity (99.8%) to DMC, and that Cl− and Cu2+ have a synergetic effect. The Lewis acid sites of the γ-Al2O3 support may be suitable for vapor-phase carbonylation of methyl nitrite to DMC. Moreover, the catalytic mechanism of DMC formation on the (Pd–CuCl2)/γ-Al2O3 catalyst has been reasonably proposed based on the results of XPS and in situ diffuse reflectance infrared spectroscopy. The intermediate Cl–Pd(II)–COOCH3 is the key factor for the synthesis of DMC.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2014
·
IF 2.871
Yong-Fang Li,Jing-Jing Lv,Ming Zhang,Jiu-Ju Feng,Fang-Fang Li,Ai-Jun Wang
A simple, facile, green, and controlled one-step electrodeposition method was developed for preparation of well-defined urchin-like Pd nanoparticles on a glassy carbon electrode, using nitrite ions as the growth directing agent. No any organic solvent, template, surfactant, seed, or complex apparatus was involved. The as-prepared Pd nanostructures had “clean” surfaces because of the surfactant-free formation process. The obtained Pd deposits were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The experimental parameters including deposition potential, the dosage of H 2 PdCl 4 and nitrite ions, and deposition time were investigated in details. The urchin-like Pd nanoparticles demonstrated better tolerance, enhanced electrocatalytic activity, and superior stability toward methanol oxidation in alkaline media.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）