JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Na Li,Jie Cheng,Xin Xing,Yonggang Sun,Zhengping Hao
Clarifying the oxidative products and their formation mechanisms in the catalytic oxidation of chlorinated volatile organic compounds is important to provide detailed understanding of the degradation of pollutants with the simultaneous removal of secondary pollutants. In this study, catalytic oxidation of 1,2-dichlorobenzene (1,2-DCB) using commonly commercial catalysts (Pd/γ-Al 2 O 3 , Pd/ZSM-5, and Pd/SiO 2 ) was investigated. During the oxidation processes, substantial amounts of polychlorinated organic by-products, such as trichlorobenzene, tetrachlorobenzene and pentachlorobenzene, were detected. The reaction temperature and types of supports played a vital role in the formation of chlorinated organic by-products. With an increase of the reaction temperature, the degree of chlorination of the organic by-products increased gradually, and the concentration of polychlorinated organic by-products was increased sharply at low temperatures and then decreased when the reaction temperature was above 450 °C. Meanwhile, the amounts of polychlorinated organic by-products increased with an increasing silicate-to-aluminium ratio. Furthermore, based on the distribution of chlorinated organic by-products and characterization results of pyridine from FTIR, XPS, UV–vis-DRs, and in situ FTIR, the formation mechanisms of the polychlorinated organic compounds were proposed.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
Applied Catalysis O: Open
·
2024
·
IF 0
Mingyang Liu,Yanhua Wang
An ionic liquid [CH 3 (OCH 2 CH 2 ) 22 N + Et 3 ][ p -CH 3 C 6 H 4 SO 3 − ] was synthesized and employed for stabilizing Pd nanocatalyst, which possesses the thermoregulated phase-separable property. The as-prepared Pd nanocatalyst was applied for the selective hydrogenation of 1,5-cyclooctadiene under atmospheric H 2 pressure. The >99% conversion of 1,5-cyclooctadiene with 95% selectivity towards cyclooctene was achieved under the optimal reaction conditions. The Pd nanocatalyst could be reused for six cycles without evident loss in conversion and selectivity. The turnover frequency of 4232 h −1 is greater than those of previously reported Pd nanocatalyst under atmospheric H 2 pressure.
研究领域:
催化化学
·
有机合成
·
纳米材料
·
绿色化学
✓ 已验证
DOI
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Qiao Wang,Wei Wang,Boyin Yan,Wenxin Shi,Fuyi Cui,Ce Wang
The present development gives an insight into the effect of the distribution of bimetallic sites in denitrification. A highly-dispersed Pd-Cu bimetallic catalyst supported by titanium dioxide nanofibers (Pd-Cu/TiO 2 ) was in situ fabricated by electrospinning and subsequent calcination and chemical reduction, and then applied in the catalytic reduction of water phase nitrate (NO 3 − ) to nitrogen gas (N 2 ). Compared with ex situ Pd-Cu impregnated catalyst, the in situ Pd-Cu/TiO 2 nanofibers exhibited the high nitrate removal efficiency, selectivity and fast kinetics (about twice that of impregnated ones). These good catalytic performances are mainly benefited from increased active sites and raised ratio of nitrogen to hydrogen on them, which are brought about by the well-dispersed and closely connected Pd-Cu bimetallic nanoparticles in TiO 2 nanofiber matrix. Moreover, the in situ nanofiber matrix provides a physical barrier to inhibit bimetallic nanoparticles movement, aggregation and leakage from the support into water, and hence significantly enhances the recyclability for nitrate reduction.
研究领域:
环境科学
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催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Yaqi Chen,Linrong Zhang,Jin Wang,Huixiang Sheng,Kaili Wang,Junjie Wang,Shunhao He,Liuyingzi Yu,Gang Lu
Interface/emulsion catalysis is an effective approach for many organic and inorganic chemical reactions. Positioning catalysts at the interface is essential for highly efficient interface/emulsion catalysis. The sheet-like Janus nanostructures may have great advantages in stabilizing emulsions and improving reaction efficiency. In this work, by using a simple emulsion reaction and photodeposition, we successfully prepare the Janus nanosheets with opposite sides composed of AuNPs/PdNPs and reduced graphene oxide (rGO) respectively, referred to as AuNP-rGO/PdNP-rGO Janus nanosheets . Due to the distinct hydrophilicities on opposite sides, the prepared Janus nanosheets demonstrate high efficiency in emulsion stabilization and emulsion catalysis. By introducing the prepared PdNP-rGO and AuNP-rGO Janus nanosheets in emulsion reactions, highly efficient hydrogenation of p -nitroanisole and photocatalytic degradation of Nile red are demonstrated. This work provides a simple and cost-effective method to prepare Janus nanosheets and realize highly efficient emulsion reactions, and this strategy can be extended to promote many other interface/emulsion reactions.
研究领域:
材料科学
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催化化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry B
·
2018
·Vol. 6
·期 36
·5795-5801
·
IF 4.776
Xuemei Yin,Linlin Liang,Peini Zhao,Feifei Lan,Lina Zhang,Shenguang Ge,Jinghua Yu
MicroRNAs (miRNAs) are a class of significant biomarkers; however, it is still a huge challenge to express them accurately. Herein, a fluorescent/colorimetric dual-model biosensor based upon the quenching effect of graphitic carbon nitride on palladium nanoclusters (Pd NCs) on the platform of a microfluidic paper-based analytical device was built for the detection of miRNAs. On the one hand, Pd NCs could catalyze a chromogenic reaction so that preliminary detection was achieved by the naked eye. On the other hand, the fluorescence analysis combined with nucleic acid cycle signal amplification was required to get precise result and the detection limit is 3 fM, which was superior to the previous method. What's more, this biosensor could be designed to detect other miRNAs via changing the corresponding aptamer sequences. Therefore, the as-constructed biosensor supplies a versatile platform to conduct point-of-care detection of miRNAs with outstanding performance.
研究领域:
生物化学
·
分子诊断
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纳米技术
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医学检测
✓ 已验证
DOI
PubMed
高影响因子
MACROMOLECULAR MATERIALS AND ENGINEERING
·
2017
·Vol. 302
·期 3
·1600432
·
IF 2.863
Zhicheng Liu,Zhaodong Yan,Jian Guo,Lu Bai,Lu Jia,Ping Song,Linyu Mei,Yaqing Liu
Assembly of anisotropic nanoparticles on polymeric templates has attracted much attention recently because of the potential useful applications. In this work, 3D electrospun nanofiber membrane is used as template for the assembly of ex situ synthesized palladium nanocubes. The assembly process is achieved by simple immersion step, in which the electrostatic assembly of the nanocubes occurs. The dense nanocubes on the nanofibers as well as the fibrous nanostructure render the nanocomposite membrane excellent catalytic activity. Moreover, the catalytic membrane can be recycled for at least six times, which makes it possible for practical usage.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
ChemSusChem
·
2016
·Vol. 10
·期 5
·976-983
·
IF 7.116
Xin Li,Xiangheng Niu,Wenchi Zhang,Yanfang He,Jianming Pan,Yongsheng Yan,Fengxian Qiu
Graphical One pot for MORe : A one-pot dopamine self-polymerization mediated redox strategy is used to fabricate highly dispersed Pd nanoparticles anchored on a nitrogen-doped carbon support. The material is used to catalyze the methanol oxidation reaction (MOR) with higher mass activity and durability than commercial Pd/C. Exploration of advanced electrocatalysts to promote the sluggish methanol oxidation reaction (MOR) is of vital importance for developing high efficiency and low-cost direct methanol fuel cells. Highly dispersed palladium nanoparticles (Pd NPs) anchored on a nitrogen-doped carbon support were fabricated using a facile one-pot dopamine self-polymerization mediated redox strategy, in which dopamine not only acted as a moderate reductant to induce the formation of Pd NPs during self-polymerization but was also the precursor of the nitrogen-doped carbon support for Pd. The synthesized hybrid features the following characteristics: 1) High dispersity of Pd NPs, which exposed a high abundance of active surfaces and sites for heterogeneous electrocatalysis; 2) metal-support interactions, which may affect the surface chemistry and electron distribution of active Pd NPs; 3) the Pd NPs were partially imbedded or encapsulated into the support, thus reducing the possible agglomeration of Pd NPs during cyclic measurements. The electrocatalyst with such favorable features provided higher mass activity (2.2 times that of commercial Pd/C) and better durability (reduced loss of activity during simulated frequent startup–shutdown operations) for the MOR in alkaline media.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF CATALYSIS
·
2024
·
IF 6.5
Tian-Hong Jing,Yi-Ying Zhuang,Xiao-Xin Zhang,Jian-Guo Qian,Xiao-Li Zhao,Yong Lu,Hai-Jing Wang,Ye Liu
The elaborate control of regioselectivity regulated by the involved ligands with specific structural skeleton and compositions is always demanded in alkoxycarbonylation of alkenes. Herein, a series of pinwheel-like tridentate phosphine ligands with rotatable flexibility ( L3 ) or hard rigidity ( L5–L7 ) were synthesized and characterized for the first time, in which the incorporated three PPh 2 -fragments are located at meta-positions of phenyl groups. It was proved that the tridentate phosphine of L3 with the flexible configuration favorably corresponded to the linear regioselectivity with l/b ratio of 98/2, whereas L7 with the rigid configuration absolutely did favor to the branched regioselectivity with l/b ratio of 1/99. The presence of the three PPh 2 -frgaments in L3 did contribute to the remarkable performance of L3 -Pd(TFA) 2 system in terms of activity, linear regioselectivity and stability, subjected to 10-run recycling uses in anti -Markovnikov’s methoxycarbonylation of styrene without activity loss and Pd-black precipitation. In comparison, although the optimal L7 -Pd(MeCN) 2 Cl 2 system could catalyze Markovnikov’s alkoxycarbonylation of alkenes to afford the branched esters with excellent regioselectivity in the fresh use, its stability was too poor to support the recycling experiments. L3 -Pd(TFA) 2 and L7 -Pd(MeCN) 2 Cl 2 catalytic systems were both applicable to a wide range of substrates in alkoxycarbonylation of alkenes to afford the target esters in the isolated yields of 41–91 %, with the well maintained divergent regioselectivity.
研究领域:
有机化学
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
·
2022
·
IF 4.198
Yi-Fan Wang,Yu-Han He,Yan Su,Yang Ji,Rui Li
A palladium complex coordinated with a chiral SIPHOS ligand was evaluated as an efficient catalyst for asymmetric hydrosilylation of β-silyl styrenes with trichlorosilane and 23 1,2-bis(silyl) chiral compounds were produced. Good to excellent enantioselectivities were observed with 1-aryl-2-silyl ethanols, where the trichlorosilyl groups of the hydrosilylation products were selectively converted into a hydroxyl group in the presence of pre-installed trialkylsilyl groups. Asymmetric hydrosilylation of β-silyl styrenes followed by methylation of the trichlorosilyl group gave stable 1,2-bis(silyl) chiral compounds 4 with excellent yields. DFT calculations of hydridopalladium B coordinated with a SIPHOS ligand, an intermediate of the hydrosilylation reaction, established the optical structures to be energy minima, and the structural information could well illustrate the enantioselectivity for the hydrosilylation reaction.
研究领域:
有机化学
·
催化化学
·
理论计算化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Tianyu Guo,Xiaorong Nie,Jianping Du,Jinping Li
Methane oxidation is a strong exothermal reaction, the heat released from which can be utilized and the greenhouse effect caused by emitted methane, particularly low-concentration methane (LCM), can be further relieved. Presently, one of the key problems is to develop an efficient catalyst material for promoting LCM oxidation. Here, we synthesized an alumina with 2D feather-like lamella structure (FLAO), which is suitable for industrial applications. The samples were characterized by X-ray diffraction, scanning/transmission electron microscopy, X-ray photoelectron spectroscopy and nitrogen adsorption/desorption techniques. The results show that as-synthesized alumina has feather-shaped morphology and 2D slices structures, which form loose framework. Pd nanoparticles were easy to be anchored and well-dispersed on the surface of alumina. The FLAO-supported Pd catalysts exhibited high activity and stability. For 360000 mL g −1 h −1 space velocity, the LCM conversion research above 90% at 400 °C, and only decrease 8.6% after 50 h reaction at 450 °C, suggesting that as-synthesized 2D alumina slice has potential application for highly efficient removal of low-concentration methane from ventilation air.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Frontiers of Chemical Science and Engineering
·
2017
·Vol. 12
·期 1
·24-31
·
IF 1.712
Han Dongxu,Zhang Zhiguo,Bao Zongbi,Xing Huabin,Ren Qilong
We have successfully prepared a series of Pd-Ni/TiO 2 catalysts by a one-step impregnation-reduction method. Among these catalysts with different compositions of Ni and Pd, the one with the Ni:Pd ratio of 2.95 showed the best activity. Small monodispersed Pd-Ni bimetallic nanoparticles were loaded on the surface of titanium oxide nanopowder as confirmed with TEM and EDS mapping. The XPS analysis demonstrated that Pd exists as 31% Pd(II) species and 69% Pd(0) species and all nickel is Ni(II). The prepared Pd-Ni/TiO 2 exhibited enhanced catalytic activity compared to an equal amount of Pd/TiO 2 for Suzuki-Miyaura reactions together with excellent applicability and reusability.
研究领域:
化学
·
材料科学
·
催化反应
✓ 已验证
DOI
高影响因子
CATALYSIS LETTERS
·
2017
·Vol. 147
·期 10
·2534-2541
·
IF 2.799
Zhang Chenjun,Lu Dan,Jiang Pingping,Li Jingjing,Leng Yan
Abstract A novel porous cross-linked chitosan polymer was prepared by Schiff reaction of chitosan (CS) with terephthalic aldehyde (TPA), followed by modification with trimethoxysilylpropanethiol. Such functional CS polymer (CS-TPA) could serve as both support and stabilizer for homogeneous palladium (Pd 2+ ) catalyst. The obtained heterogeneous catalyst (Pd/CS-TPA-SH) exhibited high catalytic activity and selectivity for the oxidative Heck reaction of benzene and ethyl acrylate. The excellent performance is mostly attributed to the –SH groups stabilized Pd 2+ species. Furthermore, Pd/CS-TPA-SH can also be used as the catalyst for the reduction of p-nitrophenol at room temperature, showing high efficiency and steady reusability. Graphical Abstract A novel thiol functionalized cross-linked chitosan polymer supporting palladium is synthesized and proved to be a highly efficient catalyst for oxidative Heck reaction and nitrophenol reduction.
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
危险品化学品经营许可证（带存储）