INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2020
·
IF 4.939
Feipeng Wang,Kelin Hu,Hongcheng Liu,Qi Zhao,Kaizheng Wang,Yuxin Zhang
In this work, we introduced a structure of Pd coated SnO 2 nanofiber rods (NFRs) prepared by electrospinning and magnet sputtering. Pd was first deposited on the obtained nanofibers as a catalyst and then fully dispersed during the resulting of SnO 2 to improve the hydrogen response. The gas sensing tests showed the palladium enhanced the hydrogen response at low temperature (160 °C). When the hydrogen gas concentration was 100 ppm, the limit of detection (LOD) of sensor was as low as 0.25 ppm and the response time was as short as 4 s. Moreover, Pd coated SnO 2 also had excellent hydrogen selectivity and repeatability. The gas sensor was suitable for the detection of hydrogen in low-temperature environment. This work provided a new method for the low temperature hydrogen gas sensor with a fast response and low LOD .
研究领域:
材料科学
·
传感器技术
·
纳米材料
·
气体传感
·
功能材料
·
电纺丝技术
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2013
·Vol. 34
·期 12
·2161-2166
·
IF 1.304
Mingming Zhang,Manman Jiang,Changhai Liang
A basic anion exchange resin , Amberlite IRA-900, was loaded with Pd(C 3 H 5 )(C 5 H 5 ) by an easy metal-organic chemical vapor deposition (MOCVD) approach to give Pd@IRA-900 catalyst after reduction at room temperature . Ultraviolet-Visible spectroscopy results showed a red shift of the absorption peak of Pd 2+ after the Pd precursor was loaded on the resin, indicating that a chemical reaction occurred between the precursor and the support. Pd nanoparticles with 2.6 nm of average size were well dispersed on the support. The Pd@IRA-900 catalyst showed high activity for different kinds of aryl halides in Suzuki-Miyaura coupling reactions under mild and aerobic conditions. Excellent recyclability of Pd@IRA-900 catalyst was also observed in the Suzuki-Miyaura coupling reaction of iodobenzene and phenylboronic acid . A bifunctional catalyst Pd@IRA-900(OH) was synthesized by pretreating the ion exchange resin support with NaOH before Pd loading, which successfully catalyzed the Suzuki-Miyaura reaction of iodobenzene and phenylboronic acid without base under aerobic conditions.
研究领域:
催化化学
·
有机合成
·
材料化学
·
绿色化学
·
纳米催化
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
·
2019
·Vol. 21
·期 19
·5336-5344
·
IF 9.405
Da Yang,Huan Liu,Lei Liu,Wen-Di Guo,Yong Lu,Ye Liu
An amphiphilic tri-functional ligand (L1) containing a Lewis acidic phosphonium cation, a phosphino-fragment and a hydrophilic sulfonate anion (–SO3−) enabled Pd(OAc)2 to efficiently co-catalyze the hydroxycarbonylation of terminal alkynes towards α,β-unsaturated carboxylic acids. These incorporated functional groups synergistically promoted the reaction, which proved more effective than the ligands lacking –SO3− and/or phosphonium and the mechanical mixtures of the individual functional groups independently. The molecular structure of Pd-L1 indicated that –SO3− in L1 served as a secondary O-donor ligand with reversible coordinating ability, cooperating with the phosphino-fragment to stabilize the Pd-catalyst. The in situ FT-IR analysis verified that the formation and stability of Pd–H active species in charge of hydroxycarbonylation were dramatically facilitated by the presence of L1. It was believed that, over the L1-based Pd-catalyst, H2O was cooperatively activated by the Lewis acidic phosphonium via “acid–base pair” interaction (H2O → P(V)+) and by the hydrophilic SO3−via hydrogen bonding (SO3−⋯H2O), giving rise to the formation of dimeric and mono-nuclear Pd–H species driven by reversible SO3−-coordination. In addition, the L1-based Pd-catalyst could be immobilized in the ionic liquid [Bmim]NTf2 for six-run recycling uses without obvious activity loss and detectable metal leaching.
研究领域:
有机化学
·
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Yanyan Wang,Yu Liu,Jiyang Li,Yuanyuan Liu,Weiqiang Zhang,Mingming Yang,Yajun Jian,Ping Zuo,Ziwei Gao
The position of Pd species in/on zeolites is crucial for the activity of metal/metal oxide catalysts. It is still a challenge to highly disperse and stabilize the metal species on zeolites and shorten diffusion paths to maintain high catalytic activity. Here, we report an effective strategy for preparing highly efficient zeolite-supported Pd(II) catalysts by positioning Pd(II) species on the surface of a zeolite with an anion framework based on the principle of charge balance. The catalyst was prepared in situ in a C–C cross-coupling reaction. Due to the change in the metal–support interaction, Pd species have migrated from the inside to the surface of the zeolite, which shortens the diffusion path of reactants and thus ensures the high activity of the catalyst. Pd species exhibit aggregation resistance in alkaline systems and tend to be confined in the traps with high charge density. Compared to unactivated Pd@USY, the efficiency of the activated catalysts has at least doubled in catalyzing the Sonogashira and Suzuki–Miyaura reactions. This study represents a new activation approach for zeolite-supported Pd catalysts, which may help to design efficient catalysts.
研究领域:
催化化学
·
材料化学
·
有机合成
·
纳米催化
·
多相催化
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Chuanxia Chen,Wendong Liu,Pengjuan Ni,Yuanyuan Jiang,Chenghui Zhang,Bo Wang,Jinkai Li,Bingqiang Cao,Yizhong Lu,Wei Chen
Enzyme-like activity and efficiency of nanomaterials are strongly controlled by their size, composition, and structure, and hence the structural parameters need to be optimized. Here, we report that two-dimensional Pd nanoplates enclosed by {100}-facets [{100}PdSP@rGO] exhibit substantially enhanced intrinsic oxidase-like activities relative to the {111}-facets ones and Pd nanocubes in catalyzing the chromogenic reaction of 3,3′,5,5′-tetramethylbenzidine. By taking ascorbic acid 2-phosphate as the substrate, which transforms to ascorbic acid in the presence of acid phosphatase (ACP), the {100}PdSP@rGO could be used as an efficient nanozyme for colorimetric ACP detection without resorting to destructive H2O2. A good linear relationship from 0.01 to 6.0 mU/mL with a detection limit of 8.3 μU/mL is obtained, which is better than most previously reported ACP assays. Importantly, the excellent assay performance could be successfully applied to ACP determination in serum samples with high accuracy. This study demonstrates that the enzyme-like activity of nanomaterials could be finely tuned simultaneously by controlling their exposed crystal facets and high specific surface area.
研究领域:
纳米酶学
·
生物分析化学
·
分子诊断
·
纳米材料学
·
临床检验医学
✓ 已验证
DOI
高影响因子
PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2014
·
IF 3.828
Yichen Zong,Shuiqing Li,Fang Niu,Qiang Yao
The titania supported palladium nano catalysts (Pd/TiO 2 ) are synthesized in one-step using a premixed stagnation swirl flame (SSF) with ultra-fine spray system. This novel SSF method, with features of short residence time and fast quenching, produces nanosized (<2.5 nm) palladium particles being well dispersed on the 7–8 nm TiO 2 particle surface, with an overall specific surface area of 210–220 m 2 /g. The X-ray photoelectron spectroscopy (XPS) results indicate that the collected palladium particles are a mixture of both Pd and PdO, whereas the TiO 2 support is mainly in anatase phase by X-ray diffraction (XRD). A revised population balance model (PBM) by incorporating coagulation, sintering and scavenging of the binary system (Pd and TiO 2 ) is developed to explain the in situ doping mechanism of Pd/TiO 2 composites in the flame domain. Then, we use the synthesized nano catalyst to conduct the catalytic combustion of methane under 5–15% Pd loadings. It exhibits more excellent activity than those in the literature under identical temperatures. The T 20 , as 20% methane conversion temperature, can reduce to as low as 293 °C at 15% Pd loading. It is because that the Pd/TiO 2 catalysts made from the stagnation flame show a good dispersion of size-controlled palladium on TiO 2 which may not be accessible by wet-chemistry and even other flame synthesis routes.
研究领域:
材料化学
·
环境催化
·
纳米材料
·
能源工程
·
燃烧科学
✓ 已验证
DOI
高影响因子
CELLULOSE
·
2019
·Vol. 26
·期 12
·7355-7370
·
IF 3.917
Dong Yahao,Bi Jiajun,Zhu Dajian,Meng Di,Ming Shujun,Guo Wen,Chen Zhen,Liu Qian,Guo Lei,Li Tao
Due to their eco-friendly nature, polysaccharides are desirable supporting materials in organic transformations. Nevertheless, as is the case for other supports, polysaccharides have to face the issue of seeking more binding sites via multifunctional structures to capture metal species in the catalyst, which enhance stability and promote catalytic performance in aforementioned process. In this paper, an environmentally-friendly and multifunctional cellulose supported Pd(II)-Schiff base complex is fabricated and applied in the formation of different biaryls under mild ambient conditions. The results of thermal analysis reveal that the composite has high thermal stability. The as-prepared catalyst demonstrates to be a robust and efficient catalyst with more than 90% yields in H 2 O: EtOH (1:1) at 70 °C by using 0.30 mol% of catalyst under air towards the coupling of various substituted aryl halides and phenylboronic acids. Moreover, identified by ICP-OES analysis, the green Pd(II) catalyst displays higher metal content (1.93%) in comparison with the direct deposition of Pd particles on cellulose (0.93%), and prevents the metal leaching (< 1%) via the coordination interaction of multiple capturing sites (–OH, Schiff base and pyridyl moieties) with palladium. The resultant catalyst is characterized by FT-IR, TGA, XRD, SEM, TEM, XPS, CP/MAS 13 C-NMR, and ICP-OES examination. Also, this green catalyst is able to be retrieved in five cycles with simple centrifugation. Notably, we propose a plausible multifunctional catalyst complex. The present study offers a novel and effective supported catalyst, which broadens the contributions of polysaccharides in green catalysis. Graphic abstract
研究领域:
高分子化学
·
绿色化学
·
有机催化
·
材料化学
·
环境友好材料
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
·
2011
·Vol. 13
·期 10
·2939-2947
·
IF 5.472
Guang Li,Hengquan Yang,Wei Li,Guoliang Zhang
An IPr-functionalized (IPr = N,N′-bis(2,6-diisopropylphenyl)imidazol-2-ylidene, a N-heterocyclic carbene ligand) mesoporous ethane-silica was synthesized through a co-condensation of IPr-bridged triethoxysilane and bis(triethoxysilyl)ethane. This functionalized mesoporous ethane-silica was characterized with N2 sorption, XRD, FT-IR, solid NMR and XPS. Owing to high surface area, large pore volume and organically functionalized surface, such a material can be used as a scaffold to design surface NHC-Pd [NHC = N-heterocyclic carbene] complexes. By variation of Pd precursors and/or ancillary ligands, a library of NHC-Pd complexes on the solid surface were tentatively created. It was found that the Pd precursor and ancillary ligands had significant impacts on the activities of the resultant heterogeneous catalysts in the Suzuki–Miyaura coupling of aryl chlorides. Surface NHC-Pd complexes with acetylacetonate (acac) and 3-chloropyridine as ancillary ligands are the most active. A wide range of aryl chlorides even with deactivated and sterically hindered groups were successfully coupled over this solid catalyst under the mild conditions at a relatively low loading of Pd (80 °C, 0.5 mol% Pd). This solid catalyst could be reused 10 times without a significant decrease in activity. This study not only provides the most efficient phosphine-free solid catalyst for the Suzuki–Miyaura couplings of less reactive substrates, but also demonstrates a noteworthy example that IPr-functionalized ethane-silica can be used as a versatile scaffold to create various active surface NHC-metal catalysts.
研究领域:
催化化学
·
有机合成
·
材料化学
·
绿色化学
·
均相与多相催化
✓ 已验证
DOI
高影响因子
Nano Research
·
2016
·Vol. 10
·期 3
·1064-1077
·
IF 8.893
Qiu Pengtao,Lian Shaomin,Yang Guang,Yang Shengchun
We demonstrate a facile hydrothermal one-pot synthesis method for producing single crystalline mesoporous PtPd bimetallic nanoparticles with a hollow interior and porous surface structure in the presence of Br – and I – ions. The formation process analysis indicated that the coexistence of Br – and I – ions is responsible for the formation of the novel bimetallic nanoparticles. The changes in the reduction potential of Pt and Pd metal ions achieved by the coordination with different halide ions resulted in the formation of hollow interiors as a galvanic reaction between Pd 2+ and Pt 4+ ions occurred. In addition, the size of the mesoporous PtPd nanoparticles can be well controlled by slightly changing the amount of I – ions used. The electrochemical tests indicated that the assynthesized single crystalline mesoporous PtPd hollow nanoparticles exhibited enhanced catalytic properties toward methanol and ethanol oxidation reactions as compared with the commercial Pt black and Pt/C materials.
研究领域:
材料科学
·
电化学
·
纳米技术
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2017
·
IF 4.798
Jue Wang,Hai-yang Pan,Yan-yue Ding,Yong-chao Li,Chang Liu,Fei Liu,Qin-fang Zhang,Guang-hou Wang,Min Han
Pd nanoparticles with a mean diameter of 6.7 nm are prepared by gas phase cluster beam deposition. The Pd nanoparticle films exhibit excellent catalytic activity and stability for methanol oxidation. 3D hybrid nanostructures combined with multi-walled carbon nanotubes and few-layer graphene sheets are used as supports to further enhance the methanol electro-oxidation activity of the Pd nanoparticle catalysts by a factor of more than 2.7. The catalytic activity towards methanol electro-oxidation is characterized with cyclic voltammetry measurements. An ultrahigh electrochemical active surface area (ECSA) as large as 311 m 2 g −1 pd and a mass specific current corresponding to methanol oxidation levels as high as 4038 mA mg −1 pd are realized. These results can be attributed to the high electrochemical activity of the Pd nanoparticles and the unique conductive structure of the multi-walled carbon nanotubes/few-layer graphene sheets.
研究领域:
材料科学
·
电化学
·
纳米技术
✓ 已验证
DOI
高影响因子
Polymer Chemistry
·
2015
·Vol. 6
·期 35
·6351-6357
·
IF 5.52
Xiaoyu Jiang,Wuxue Zhao,Wei Wang,Fan Zhang,Xiaodong Zhuang,Sheng Han,Xinliang Feng
Two novel Pd-loaded heteroatom-linked microporous polymers Pd@NP and Pd@NPO were effectively synthesized by one-pot Pd-catalyzed Heck coupling reactions of tris(4-vinylphenyl)amine with tris(4-bromophenyl)phosphine and tris(4-bromophenyl)phosphine oxide, respectively. The Pd atoms loaded into the networks of the resulting porous polymers originated from the Pd-catalyst used in the polymerization, which was achieved under moderate reaction conditions. Besides the nitrogen atoms, the trivalent phosphorus atoms bearing one lone pair of electrons and the pentavalent phosphorus atoms of the phosphoryl groups were used as the linkers for the formation of the frameworks of the porous polymers Pd@NP and Pd@NPO, respectively. The phosphorus atoms with different oxidation states in the networks caused a dramatic variation in the physical and catalytic properties of the as-prepared porous polymers. Pd@NP and Pd@NPO exhibit surface areas of 381 m2 g−1 and 684 m2 g−1, respectively. Both Pd-loaded porous polymers enable efficient Suzuki–Miyaura coupling reactions featuring short reaction times and good yields, with the catalysts being highly stable and easy to recycle. The catalytic activity of Pd@NPO is higher than that of Pd@NP.
研究领域:
材料化学
·
有机化学
·
催化化学
·
高分子科学
·
纳米功能材料
✓ 已验证
DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2016
·Vol. 42
·期 6
·6181-6190
·
IF 1.833
Wang Meng-Meng,Liu Shi-Wei,Li Lu,Yu Shi-Tao,Xie Cong-Xia,Song Zhan-Qian
Rosin hydrogenation using polyvinylpyrrolidone (PVP)-stabilized Pd colloidal nanoparticles as catalyst in an aqueous/organic biphasic system was investigated. The influence of preparation methods on the size of Pd nanoparticles for hydrogenation of rosin was marked. Compared with traditional catalysts Pd/C and Raney-Ni, PVP-stabilized Pd colloidal nanoparticles showed excellent catalytic activity and promoted formation of the product tetrahydroabietic acid (THAA). More than 93 % rosin was hydrogenated, and the mass fraction of THAA was 54.2 % when the reaction was carried out at 160 °C for 4 h. It was also found that PVP-stabilized Pd colloidal nanoparticles exhibited good reusability for hydrogenation, with no obvious decrease in catalytic performance when reused six times.
研究领域:
催化化学
·
纳米材料
·
有机合成
·
绿色化学
·
胶体化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）