INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Xingjie Yang,Xubao Jiang,Muhammad Sohail Bashir,Xiang Zheng Kong
Polyurethanes (PUNs) have been widely used in many fields. However, there are few reports on their microsphere preparation through precipitation polymerization. Herein, uniform PUN microspheres are prepared by precipitation polymerization of toluene diisocyanate and trimethylolpropane, without any surfactant and stabilizer. Under optimized conditions, monomers are fully polymerized within 2 h at a monomer concentration as high as 25.0 wt %, with a high yield of the microspheres (96.9%). By loading Pd on their surface, composite microspheres Pd@PUN are obtained and used as catalysts. 4-Nitrophenol is completely reduced within 1 min, with a kinetic constant of 4.96 min–1, significantly higher than many reported Pd-loaded catalysts, and with comparable reusability. Used in degradation of dye molecules, the catalytic performance is practically unchanged after 20 recycled uses. This work provides a simple method for the preparation of highly uniform PUN microspheres with a high yield and their Pd-loaded catalysts, both of great potential for various applications.
研究领域:
材料科学
·
催化化学
·
环境科学
✓ 已验证
DOI
高影响因子
Cell Reports Physical Science
·
2023
·
IF 8.9
Zheng Hu,Hui Li,Wenbo Zhao,Wei Zhou,Shi Hu
Structural information in a disordered atomic system cannot be acquired from everyday X-ray diffractometers, so we have to resort to synchrotron resources. The pair distribution function from synchrotron X-ray and neutron scattering reflects the local bond information regardless of the crystallinity, but the limited access to these high-energy light resources prevents them from widespread use. Here, we develop a microstructure analysis framework to study immiscible binary alloys through the integration of local elemental segregation analysis, electron-based pair distribution function, the corresponding wavelet coherence spectrum, and ab initio level simulation. All the information can be obtained from an in-house transmission electron microscope equipped with an energy-dispersive spectroscope. A series of nanoparticles based on immiscible Pd-Ru alloys are chosen as model catalysts for the hydrogen evolution reaction, and the structure-performance relationship is established on the basis of the electrochemical tests and structural information from the analysis toolkit we developed.
研究领域:
材料科学
·
催化化学
·
电子显微学
✓ 已验证
DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2016
·Vol. 16
·期 7
·7642-7646
·
IF 1.338
Lu Pan,Zhang Jing,Luo Muhua,Wu Qiang,Yao Weifeng
Monodisperse Pd nanocubes with an average particles size of 10.5 nm (Pd-NCs-11 nm) and 8.4 nm (Pd-NCs-8 nm) and Pd nanospheres with an average particles size of 3.6 nm (Pd-NPs-4 nm) were successfully synthesized by controlling the amount of Br− in the Pd precursor solution.
The prepared Pd nanocubes exhibited a much enhanced electrocatalytic activity for ethanol oxidation compared to that of Pd nanospheres. The CV peak current density of ethanol oxidation over Pd-NCs-11 nm is about 39.0-fold as large as that on Pd-NPs-4 nm. The high catalytic activity of Pd nanocubes
is attributed to the particular particle shape and the large electrochemical active surface areas (EASA) of Pd nanocubes.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Science of Advanced Materials
·
2019
·Vol. 11
·期 1
·50-55
·
IF 1.158
Li Junjing,Wang Huan,Cui Yuqi,Luan Cong,Wang Liang,Zhang Zhaohui,Zhao Bin,Ma Chang,Zhang Hongwei,Cheng Xiuwen
Understanding the kinetics during electrochemical hydrodechlorination was of great importance to the design of treatment process. In this study, the six isomers of dichlorophenol were subjected to electrochemical hydrodechlorination using homemade palladium/polypyrrole/foam nickel electrode.
Under the conditions of dechlorination current is 5 mA, temperature is 25 °C, initial concentration of pollutants is 0.5 mmol L–1, electrochemical dechlorination time is 120 min, the dechlorination processes of 2,3-dichlorophenol (2,3-DCP), 2,4-dichlorophenol (2,4-DCP),
2,5-dichlorophenol (2,5-DCP), 2,6-dichlorophenol (2,6-DCP), 3,4-dichlorophenol (3,4-DCP) and 3,5-dichlorophenol (3,5-DCP) were compared. The degradation of dichlorophenol reaction followed pseudo-first-order kinetics. During the electrolysis process, the products of six DCP (dichlorophenol)
isomers dechlorination are mainly phenol, a small amount of monochlorophenol produced at the same time. The classification kinetics of six kinds of DCP (dichlorophenol) was studied according to the dechlorination path. Then the reaction rate constants of different reaction stages were obtained.
Besides, we speculated that the degradation rates of six DCP isomers were affected by pK
a
and molecular structure.
研究领域:
环境科学
·
电化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
·
2019
·
IF 4.745
Shanjian Mao,Yinbo Wan,Haiyun Peng,Li Luo,Guisheng Deng
Pd(PPh3)2Cl2-catalyzed selective tandem cyclization/oxidation of available conjugated diazo ene-yne-ketones under O2 atmosphere led to the formation of diazo trisubstituted furans. The Rh2(OAc)4-mediated selective C(sp2)–H insertion at the ortho-position of 2-aryl group (R1) of the furan moiety under N2 atmosphere occurred to construct naphthalene cycle, affording trifunctionalized naphtho[1,2-b]furans. C(sp2)–H insertion at the 4-position of the furan ring, and Wolf rearrangement of diazo moiety have not been observed.
研究领域:
有机化学
·
合成化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2022
·Vol. 57
·期 14
·7276-7289
·
IF 4.682
Wang Yonghan,Hu Feng,Chen Ying,Wang Hui,Fetohi Amani E.,Hao Yanan,Li Linlin,El-Khatib K. M.,Peng Shengjie
Electrocatalytic conversion from carbon dioxide with main products of carbon monoxide and hydrogen provides an economic and sustainable pathway to produce syngas, while the involved electrocatalysts with high activity and stability as well as highly tunability for CO/H 2 ratio are still rare. Here, we report a facile method to prepare palladium (Pd) nanoparticle ensembles with unique three-dimentional (3D) architecture and porosity as well as plenty of grain boundaries, which are electrocatalytically active for electrochemical carbon dioxide reduction (eCO 2 RR) to syngas. At the potential of − 0.8 V (versus reversible hydrogen electrode), the CO selectivity of such Pd nanoparticle ensembles is up to ca. 90% and the CO/H 2 ratio can be adjusted from one to six by varying the applied potentials. The syngas production on Pd nanoparticle ensembles can be further regulated by changing the reaction temperature and modified ligands. This method for fabricating Pd nanoparticle ensembles with rational tenability paves the way for the fundamental research and commercial deployment of eCO 2 RR and syngas production. Graphical abstract Pd nanoparticle ensembles with grain boundaries and high porosity were developed for tunable CO 2 conversion to syngas under ligand exchange and temperature control.
研究领域:
材料科学
·
电化学
·
能源转换
✓ 已验证
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2019
·
IF 3.834
Tongxin Song,Fei Gao,Yangping Zhang,Ping'er Yu,Cheng Wang,Yukihide Shiraishi,Shujin Li,Caiqin Wang,Jun Guo,Yukou Du
At present, it is still a great challenge to control the morphology and size of nanoparticles for obtaining more efficient and stable catalysts for direct fuel cell reactions. Herein, we have synthesized a series of Pd 3 Sn bimetallic catalysts with different morphologies that transitioned from nanonetwork to nanostrips and then to nanodots by altering the varieties of reducing agents and the amount of surfactant. And the formation mechanisms of nanocatalysts were also investigated. It is worth noting that Pd 3 Sn-dots, due to the unique structure, uniform dispersion and ultra-small size, exhibit excellent electrocatalytic activity for ethanol oxidation reaction and ethylene glycol oxidation reaction, which distinctly higher than the other Pd 3 Sn catalysts and commercial Pd/C catalysts. Moreover, the as-prepared Pd 3 Sn catalysts also performed greater long-term durability due to the electronic and synergistic effects. This work provides guidance on the morphology-dependent nanocrystals, which will show a great potential as anodic catalysts in direct fuel cell applications.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2021
·
IF 6.558
Zhenxing Wang,Hongli Zhao,Kaicha Chen,Hongyuan Li,Minbo Lan
Signal amplification is crucial to improve the sensitivity for the electrochemical detection of cardiac troponin I (cTnI), one of the ideal biomarkers for early acute myocardial infarction (AMI) diagnosis. Herein, we developed a novel signal amplification strategy to construct a sandwich-type electrochemical aptasensor for the detection of cTnI. Core-shell [email protected] dendritic bimetallic nanoparticles loaded on melamine modified hollow mesoporous carbon spheres ( [email protected] DNs/NH 2 -HMCS) was prepared as labels to conjugate with thiol-modification DNA aptamers probe for signal amplification. While introducing numerous amino groups, the melamine functionalized hollow mesoporous carbon spheres (NH 2 -HMCS) retained the edge-plane-like defective sites for the adhesion and electrocatalytic reduction of H 2 O 2 . With the unique characteristics of NH 2 -HMCS, it not only enhanced the dispersity and loading capacity of core-shell [email protected] dendritic bimetallic nanoparticles ( [email protected] DNs), but also improved the stability of bonding by the affinity interaction between [email protected] DNs and amino groups of melamine. Meanwhile, the synergistic catalysis effect between [email protected] DNs and NH 2 -HMCS significantly enhanced the electrocatalytic reduction of H 2 O 2 and further amplified the signal. Under optimal conditions, this recommended aptasensor for cTnI detection displayed a wide dynamic range from 0.1 pg/mL to 100.0 ng/mL and a low detection limit of 15.4 fg/mL (S/N = 3). The sensor also successfully realized the analysis of cTnI-spiked human serum samples, meaning potential applications in AMI diagnosis.
研究领域:
医学诊断
·
纳米材料科学
·
生物传感技术
✓ 已验证
DOI
PubMed
高影响因子
TETRAHEDRON
·
2018
·
IF 2.377
Yunlong Wang,Quanling Suo,Limin Han,Linlin Guo,Yaqi Wang,Fawang Li
An efficient protocol for the synthesis of unsymmetrical 1,3-diynes was developed using supercritical carbon dioxide (ScCO 2 ) as the solvent. The direct coupling of two different terminal alkynes is catalysed by a bimetallic catalyst , CuCl 2 ·2H 2 O/Pd(NH 3 ) 4 Cl 2 ·H 2 O, in the presence of the base tetramethylethylenediamine (TMEDA) and O 2 . In pure ScCO 2 , our bimetallic catalytic system maintains high activity over a wide substrate scope to provide unsymmetrical 1,3-diynes in good to excellent yields. In the proposed reaction mechanism, the synergistic cooperation between copper(II) and palladium(II) centres is responsible for the superior selectivity of the cross-coupling.
研究领域:
有机化学
·
绿色化学
✓ 已验证
DOI
高影响因子
Scientific Reports
·
2015
·Vol. 5
·期 1
·1-9
·
IF 5.578
Wang Liyuan,Feng Feng,Ma Zhanfang
Electrochemical redox-active species play crucial role in electrochemically multiplexed immunoassays. A one-pot method for synthesizing four kinds of new electrochemical redox-active species was reported using HAuCl 4 and Na 2 PdCl 4 as dual oxidating agents and aniline derivatives as monomers. The synthesized polyaniline derivative-Au/Pd composites, namely poly(N-methyl-o-benzenediamine)-Au/Pd, poly(N-phenyl-o-phenylenediamine)-Au/Pd, poly(N-phenyl-p-phenylenediamine)-Au/Pd and poly(3,3’,5,5’-tetramethylbenzidine)-Au/Pd, exhibited electrochemical redox activity at −0.65 V, −0.3 V, 0.12 V and 0.5 V, respectively. Meanwhile, these composites showed high H 2 O 2 electrocatalytic activity because of the presence of Au/Pd. The as-prepared composites were used as electrochemical immunoprobes in simultaneous detection of four tumor biomarkers (carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA199), carbohydrate antigen 72-4 (CA724) and alpha fetoprotein (AFP)). This immunoassay shed light on potential applications in simultaneous gastric cancer (related biomarkers: CEA, CA199, CA724) and liver cancer diagnosis (related biomarkers: CEA, CA199, AFP). The present strategy to the synthesize redox species could be easily extended to other polymers such as polypyrrole derivatives and polythiophene derivatives. This would be of great significance in the electrochemical detection of more analytes.
研究领域:
生物医学工程
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
Scientific Reports
·
2017
·Vol. 7
·期 1
·1-10
·
IF 4.259
Wang Guojing,Jing Shengchang,Tan Yiwei
Shape control of noble metal (NM) nanocrystals (NCs) is of great importance for improving their electrocatalytic performance. In this report, branched Pd@Rh core@shell NCs that have right square prism-like arms with preferential exposure of Rh {100} facets (denoted as b-Pd@Rh-NCs thereafter) are synthesized and utilized as an electrocatalyst for the hydrazine electrooxidation (HEO) in acidic and alkaline electrolytes. The b-Pd@Rh-NCs are obtained by the heteroepitaxial growth of Rh on the pre-formed branched Pd NCs (denoted as b-Pd-NCs thereafter) core in the presence of poly(vinyl pyrrolidone) (PVP) and bromide ions. A comparative analysis of the voltammetric data for the HEO shows a higher activity on the b-Pd@Rh-NCs exposed with Rh {100} faces than on Rh black, the b-Pd-NCs, and Pd black in acid and alkaline solutions, indicating a structure sensitivity of the reaction. Analysis of the products from the b-Pd@Rh-NCs catalysed HEO reveals a very high hydrazine fuel efficiency, as determined by on-line differential electrochemical mass spectrometry (DEMS).
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
Catalysis Science & Technology
·
2017
·Vol. 7
·期 6
·1415-1422
·
IF 5.773
Zheng Chen,Hongyan Pan,Qian Lin,Xin Zhang,Sheng Xiao,Shun He
Pd core–silica shell catalysts (PdX@SiO2, X = KBr, CTAB, SC) were prepared with and without the addition of three different functional molecules, potassium bromide (KBr), cetyltrimethyl ammonium bromide (CTAB) and sodium citrate dihydrate (SC), by the reverse micelle method, and then characterized by TEM, XRD, EDS, XPS and N2 adsorption/desorption. Results showed that the addition of functional molecules decreased the Pd particle size of the catalysts, and Br− of KBr and CTAB were selectively adsorbed on the surface of Pd particles. Among the prepared catalysts, the catalyst PdKBr@SiO2 had the highest H2O2 selectivity (98%) and productivity (716 mmol gPd−1 h−1). Compared with the catalyst Pd@SiO2 prepared without any additional functional molecules, whose H2O2 selectivity and productivity were 26% and 396 mmol gPd−1 h−1, respectively, the H2O2 selectivity and productivity of the catalyst PdKBr@SiO2 were 277% and 81% higher, respectively, than those of the catalyst Pd@SiO2. The reason for this was that the Br− of KBr can be easily selectively adsorbed on the coordinatively unsaturated sites of the Pd particle surface, which could decrease the energy of the Pd surface and restrain side reactions by inhibiting the O–O bond cleavage of O2 and H2O2. And the catalyst PdKBr@SiO2 has better stability and recyclability than the conventional supported catalyst Pd/SiO2. In contrast, the catalyst PdSC@SiO2 had the lowest H2O2 selectivity (23%) and productivity (395 mmol gPd−1 h−1) because the catalyst PdSC@SiO2 prepared with the functional molecule SC and without Br− had the smallest Pd particle size, which can lead to more coordinatively unsaturated sites and increase side reactions.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
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