Nature Communications
·
2020
·Vol. 11
·期 1
·1-8
·
IF 12.121
Xu Hong-Lei,Tkachenko Nikolay V.,Wang Zi-Chuan,Chen Wei-Xing,Qiao Lei,Muñoz-Castro Alvaro,Boldyrev Alexander I.,Sun Zhong-Ming
Sandwich-type clusters with the planar fragment containing a heterometallic sheet have remained elusive. In this work, we introduce the [K(2,2,2-crypt)] 4 {(Ge 9 ) 2 [ η 6 -Ge(PdPPh 3 ) 3 ]} complex that contains a heterometallic sandwich fragment. The title compound is structurally characterized by means of single-crystal X-ray diffraction, which reveals the presence of an unusual heteroatomic metal planar fragment Ge@Pd 3 . The planar fragment contains a rare formal zerovalent germanium core and a peculiar bonding mode of sp 2 -Ge@(PdPPh 3 ) 3 trigonal planar structure, whereas the nonagermanide fragments act as capping ligands. The chemical bonding pattern of the planar fragment consists of three 2c-2e Pd-Ge σ-bonds attaching Pd atoms to the core Ge atom, while the binding between the planar fragment and the aromatic Ge 9 ligands is provided by six 2c-2e Pd-Ge σ-bonds and two delocalized 4c-2e σ-bonds. The synthesized cluster represents a rare example of a sandwich compound with the heteroatomic metal planar fragment and inorganic aromatic capping ligands.
研究领域:
无机化学
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材料科学
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
·
2018
·Vol. 20
·期 11
·2588-2595
·
IF 8.586
Da Yang,Huan Liu,Dong-Liang Wang,Zhoujie Luo,Yong Lu,Fei Xia,Ye Liu
A bi-functional ligand (L1) containing a diphosphino fragment and sulfonic acid group (–SO3H) enabled PdCl2(MeCN)2 to efficiently catalyze the tandem bis-alkoxycarbonylation of terminal alkynes to produce aryl-/alkyl-substituted succinate (α,ω-diesters). It was found that the –SO3H incorporated in L1 indispensably assisted the Pd-catalyst in accomplishing this tandem reaction via intramolecular synergic effects. Co-catalysis over the L1-based Pd-catalyst was not due to the physical mixture of Xantphos and MeSO3H. In situ FTIR analysis verified that the formation and stability of Pd–H active species were facilitated by the presence of L1. The formation of stabilized diacylpalladium intermediate (F) was the critical driving force for the second-step methoxycarbonylation. DFT calculation was carried out to optimize the geometric structure of F, which indicated that the developed intramolecular O⋯H hydrogen bonds were an important structural feature to stabilize F. In addition, the L1-based Pd-catalyst could be recycled successfully for at least 3 runs in the ionic liquid [Bmim]NTf2 without obvious activity loss and detectable metal leaching.
研究领域:
有机化学
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催化化学
✓ 已验证
DOI
高影响因子
MOLECULES
·
2019
·Vol. 24
·期 4
·674
·
IF 3.06
Haodong Tang,Bin Xu,Meng Xiang,Xinxin Chen,Yao Wang,Zongjian Liu
Nitrogen-doped activated carbon (N-AC) obtained through the thermal treatment of a mixture of HNO3-pretreated activated carbon (AC) and urea under N2atmosphere at 600 °C was used as the carrier of Pd catalyst for both liquid-phase hydrodechlorination of 2,4-dichlorophenol (2,4-DCP) and gas-phase hydrodechlorination of chloropentafluoroethane (R-115). The effects of nitrogen doping on the dispersion and stability of Pd, atomic ratio of Pd/Pd2+on the surface of the catalyzer, the catalyst’s hydrodechlorination activity, as well as the stability of N species in two different reaction systems were investigated. Our results suggest that, despite no improvement in the dispersion of Pd, nitrogen doping may significantly raise the atomic ratio of Pd/Pd2+on the catalyst surface, with a value of 1.2 on Pd/AC but 2.2 on Pd/N-AC. Three types of N species, namely graphitic, pyridinic, and pyrrolic nitrogen, were observed on the surface of Pd/N-AC, and graphitic nitrogen was stable in both liquid-phase hydrodechlorination of 2,4-DCP and gas-phase hydrodechlorination of R-115, with pyridinic and pyrrolic nitrogen being unstable during gas-phase hydrodechlorination of R-115. As a result, the average size of Pd nanocrystals on Pd/N-AC was almost kept unchanged after liquid-phase hydrodechlorination of 2,4-DCP, whereas crystal growth of Pd was clearly observed on Pd/N-AC after gas-phase hydrodechlorination of R-115. The activity test revealed that Pd/N-AC exhibited a much better performance than Pd/AC in liquid-phase hydrodechlorination of 2,4-DCP, probably due to the enhanced stability of Pd exposed to the environment resulting from nitrogen doping as suggested by the higher atomic ratio of Pd/Pd2+on the catalyst surface. In the gas-phase hydrodechlorination of R-115, however, a more rapid deactivation phenomenon occurred on Pd/N-AC than on Pd/AC despite a higher activity initially observed on Pd/N-AC, hinting that the stability of pyridinic and pyrrolic nitrogen plays an important role in the determination of catalytic performance of Pd/N-AC.Keywords:activated carbon;hydrodechlorination;nitrogen doping;Pd
研究领域:
环境科学
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催化化学
✓ 已验证
DOI
PubMed
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 40
·24822-24827
·
IF 3.108
Ting Yu,Guoxing Yin,Peng Yin,Ying Zeng,Haitao Li,Youyu Zhang,Shouzhuo Yao
We have synthesized a novel long-wavelength fluorescent probe MFC for detection of palladium (Pd0). This probe not only shows high selectivity for palladium, but also could quickly discriminate different palladium species (Pd0, Pd2+, Pd4+) in phosphate buffered solution. After the reaction with Pd(PPh3)4, the UV absorption of the probe MFC shifts from 334 nm to 594 nm within a few minutes. The probe MFC conjugated with alkyl carbamate, which destroys the principle of intramolecular charge transfer (ICT) and shows weak fluorescence. Based on the Pd0-catalyzed Tsuji–Trost deallylation reaction, the fluorogen was released and the fluorescence intensity at 612 nm was observed with 13-fold enhancement along with an obvious color change from yellow to purple with low detection limit.
研究领域:
分析化学
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材料科学
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催化化学
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
·
2019
·Vol. 10
·期 1
·138-146
·
IF 5.726
Ting Wang,Xueqin Tao,Yi Xiao,Ganhua Qiu,Yun Yang,Benxia Li
While heterogeneous photocatalysis is regarded as a sustainable strategy to achieve organic reactions for the production of high-value-added organics, photocatalytic efficiency is generally limited by poor charge separation, dull surface catalytic activity and the consequently caused insufficient generation of active species. Herein, the hybrid structures of metal–organic frameworks (MOFs) incorporated with Pd ultrasmall nanocrystals are synthesized, and their photocatalytic performance is evaluated by the oxidative coupling of benzylamine as a model reaction. The photocatalytic activity of the Pd/MIL-125-NH2 hybrid material with an optimal Pd loading is greatly superior to that of the pristine MIL-125-NH2, achieving a high benzylamine conversion rate of 3136 μmol h−1 gcat−1 at 94.08% conversion. The enhanced charge transfer and separation in Pd/MIL-125-NH2 are verified by photoluminescence spectroscopy and photoelectrochemical experiments. Photogenerated reactive oxygen species are probed by 3,3′,5,5′-tetramethylbenzidine (TMB) as an indicator and the reactive intermediates in the photocatalytic systems are identified by in situ ESR detection. The results confirm that the optimized Pd/MIL-125-NH2 hybrid catalyst possesses higher ability for molecule activation and that both superoxide radical (˙O2−) and singlet oxygen (1O2) are the dominant oxidative species in the present photocatalytic system. Therefore, the dual advantages of Pd/MIL-125-NH2 hybrid structures for promoting the photogenerated charge transfer/separation and providing highly catalytic sites for molecule activation contribute to higher photocatalytic activity.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
FUEL
·
2025
·
IF 7.5
Dan Zhang,Maowei Luo,Xianming Zhu,Faisal Irshad,Hamzah A.S.M. Yaseen,Chao Mu,Yong Wang,Shengping Wang,Xinbin Ma
CO 2 hydrogenation to formate is a crucial process for achieving carbon neutrality. A biomass-derived N and P co-doped carbon-supported Pd catalyst (Pd/CNP) was fabricated. N and P co-doping could enhance the catalytic performance by modulating Pd electron cloud density (the Pd 0 /(Pd 2+ +Pd 0 ) ratio), promoting Pd dispersion, and increasing the content of pyrrole-N, which promoted the dissociation of H 2 and the adsorption and activation of CO 2 . Due to the strong interaction between Pd and the heteroatoms of N and P, the Pd/CNP catalyst exhibited the highest catalytic activity (TON = 1655) in samples with different doping and pyrolysis temperatures. Kinetic analysis showed that Pd/CNP reduced the activation energy of CO 2 hydrogenation to formate compared with that of Pd/C. The kinetic equation of Pd/CNP is R’= k·M NEt3-CO2 0.65 ·P H2 1.21 (NEt 3 refers to triethylamine), and NEt 3 -CO 2 is a better choice of carbon source for hydrogenation than bicarbonate and CO 2 , which is obviously different from that of Pd/C catalyst.
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产品关联
DOI
高影响因子
ACS Catalysis
·
2020
·
IF 12.35
Qiang Deng,Rui Gao,Xiang Li,Jun Wang,Zheling Zeng,Ji-Jun Zou,Shuguang Deng
Upgrading furanic aldehydes (such as furfural or 5-hydroxymethyl furfural) to cyclopentanone compounds (such as cyclopentanone or 3-hydroxymethyl cyclopentanone) is of great significance for the synthesis of high-value chemicals and biomass utilization. Developing an efficient reduced metal/acidic support with Lewis acidity is the key to facilitating the carbonyl hydrogenation and hydrolysis steps in the hydrogenative ring-rearrangement reaction. Herein, three pure Lewis acidic pyrochlore supports of the form A2B2O7 (La2Sn2O7, Y2Sn2O7, and Y2(Sn0.7Ce0.3)2O7-δ) with the same crystal structures and different metals are synthesized. The Lewis acidity and the surface properties of the pyrochlore can be tuned by inserting different kinds of A and B site metals. After impregnation, Pd nanoparticles with appropriate particle sizes are uniformly loaded on the surface of pyrochlore. For the reaction of the furanic aldehydes, all of these pyrochlore-based catalysts exhibit hydrogenation and hydrolysis rates that are both faster than those of traditional support-based catalysts due to the oxygen vacancy and pure Lewis acidity of the support. Among these pyrochlore-based catalysts, Pd/Y2Sn2O7 exhibits activity and selectivity that are higher than those of Pd/La2Sn2O7. Moreover, the Y2Sn2O7-based catalyst partially substituted by Ce3+ ions at the B site is more efficient, with the highest cyclopentanone yield and 3-hydroxymethyl cyclopentanone yield of 95.0% and 92.5%, respectively. Furthermore, the catalyst can still maintain an effective activity and stability after 4 runs. This study not only presents an efficient biobased route for the production of cyclopentanone compounds but also focuses on the acid catalytic performance of pyrochlore based on its pure Lewis acidity.
研究领域:
催化化学
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生物质利用
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材料科学
✓ 已验证
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2021
·Vol. 8
·期 9
·2280-2287
·
IF 6.569
Yangyang Ren,Chuanliang Li,Baosong Li,Fan Gao,Xinghua Zhang,Xiaojing Yang,Lanlan Li,Zunming Lu,Xiaofei Yu
Here, PtPd nanoframes were prepared by etching Pd@PdPt core–shell rhombic dodecahedrals (RDs) with Fe3+ provided by iron chloride hexahydrate (FeCl3·6H2O). Based on the experimental results, PtPd nanoframes were formed due to the etching of Pd cores. In terms of catalytic performance, the measured specific activity and mass activity of PtPd nanoframes were 1.11 mA cm−2 and 840.38 mA mg−1, respectively, which were much higher than those of Pd@PdPt core–shell RDs, Pt black and Pt/C, suggesting the preeminent activity of PtPd nanoframes. Meanwhile, PtPd nanoframes showed better stability compared with Pd@PdPt core–shell RDs, Pt black and Pt/C. The strengthened catalytic properties may be caused by the larger surface area owing to the novel structure and the strong electronic interaction between Pt and Pd.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
Frontiers of Materials Science
·
2023
·Vol. 17
·期 2
·1-10
·
IF 2.7
Liu Tianli,Zhang Jian,Xu Mingjie,Tian Chuanjin,Wang Chang-An
Sintering resistant noble metal nanoparticles are critical to the development of advanced catalysts with high activity and stability. Herein, we reported the construction of highly dispersed Pd nanoparticles loaded at the inner wall of ZrO 2 hollow spheres (Pd@HS-ZrO 2 ), which shows improved activity and thermal stability over references in the Pd-ZrO 2 (catalyst-support) system. Even after 800 °C high temperature calcination, the Pd nanoparticles and ZrO 2 hollow spheres did not undergo morphological changes. The Pd@HS-ZrO 2 manifests batter catalytic activity and thermal stability than the counterpart Pd/ZrO 2 catalysts. In comparison to Pd/ZrO 2 -800, Pd@ZrO 2 -800 exhibits a 25°C reduction in the temperature required for complete conversion of CO. The enhanced catalytic activity and thermal stability of Pd@HS-ZrO 2 can be attributed to the nanoconfinement effect offered by the 10 nm wall thickness of the ZrO 2 hollow spheres, which suppresses the coarsening of the Pd nanoparticles (active center for catalysis).
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Yang Lu,Zhenyi Wang,Wangxi Fang,Yuzhang Zhu,Yatao Zhang,Jian Jin
Porous polymeric support membranes with outstanding organic solvent resistance are highly required for fabricating thin-film composite (TFC) organic solvent nanofiltration (OSN) membranes. In this work, we report the fabrication of a high-permeance TFC-OSN membrane by the use of a polytetrafluoroethylene (PTFE) microfiltration membrane loaded with single-walled carbon nanotubes coated by a polydopamine (PD/SWCNT) network film (named the PD/SWCNT/PTFE composite membrane) as the support. Through interfacial polymerization between m-phenylenediamine and trimesoyl chloride, a polyamide (PA) thin film has successfully grown on the surface of the PD/SWCNT/PTFE composite membrane. The resulting PA TFC-OSN membrane exhibits a high methanol permeance up to 13.2 L m–2 h–1 bar–1 with a rejection rate of 89.6% to 6-hydroxy-2-naphthalenesulfonic acid sodium salt (HNSA, Mw = 246.21). Moreover, the rejection rates of the PA TFC-OSN membrane to various dyes remain unchanged before and after DMF activation, indicating that it possesses an excellent resistance to organic solvents.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2021
·
IF 5.706
Hui Chen,Jie He,Jinsheng Sun
The production of cyclohexanone, of industrial importance, is at a distance to environment friendly and efficiency. As a solution, a mild sustainable catalytic hydrogenation is presented herein, of phenol into cyclohexanone on Pd/C with potassium formate the hydrogen donor under open atmosphere. Some important reaction conditions, such as temperature, reaction time, catalyst, amount of potassium formate, etc. were investigated and analyzed. The positive growth was found to accelerate the conversion rate of phenol while reducing cyclohexanone selectivity by weakening the protection of phosphotungstic acid. Phosphotungstic acid was confirmed to be the co-catalyst exhibiting the highest activity under given conditions. Based on experiments, we have made reasonable assumptions about the reaction mechanism, while the reaction kinetics proves high reaction rates within a wide temperature range, indicating the reaction to be quick process. Furthermore, the good reusability and recyclability of Pd/C catalyst is verified to benefit future industrial applications.
研究领域:
化学工程
·
催化化学
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2018
·Vol. 42
·期 11
·9324-9331
·
IF 3.201
Jie Li,Saisai Cheng,Tianxing Du,Ningzhao Shang,Shutao Gao,Cheng Feng,Chun Wang,Zhi Wang
In this work, a porous g-C3N4 nanosheets/reduced graphene oxide (rGO) composite was synthesized via the hydrothermal co-assembly of GO and g-C3N4 nanosheets (g-C3N4 NS). Compared with g-C3N4 NS, rGO and bulk g-C3N4/rGO, the g-C3N4 NS/rGO supported Pd nanocatalyst displayed a remarkable catalytic activity for the hydrogenation of alkenes with formic acid and formates as the hydrogen source at atmospheric pressure. Among all the as-prepared Pd-g-C3N4 NS/rGO catalysts, the optimized Pd-g-C3N4 NS/rGO20 exhibited the highest turnover frequency of 133 mol mol−1 Pd h−1, which is among the highest value reported in documents. 99% conversion and 99% selectivity were achieved after 30 min reaction at 30 °C for the hydrogenation of nitrobenzene. In addition, Pd-g-C3N4 NS/rGO20 exhibited an excellently high stability after five successive cycles without significant loss of its catalytic activity.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）