JOURNAL OF CATALYSIS
·
2019
·
IF 7.723
Renshan Wang,Ganhua Qiu,Yi Xiao,Xueqin Tao,Wen Peng,Benxia Li
In this work, an all-solid-state Z-scheme photocatalyst of WO 3 ·H 2 O/Pd/CdS ternary heterostructures was constructed by introducing a small amount of Pd into the optimized WO 3 ·H 2 O/CdS binary system, where Pd nanoparticles (NPs) were sandwiched between WO 3 ·H 2 O nanosheets and CdS NPs. The WO 3 ·H 2 O/Pd/CdS ternary heterostructures exhibited remarkably enhanced photocatalysis towards the oxidative coupling of benzylamines to imines, compared with the other photocatalysts of WO 3 ·H 2 O, CdS, WO 3 ·H 2 O/CdS, WO 3 ·H 2 O/Pd, and WO 3 ·H 2 O/CdS/Pd. The wavelength-dependent photocatalysis of WO 3 ·H 2 O/Pd/CdS is in good agreement with its light-harvesting intensity at the corresponding wavelengths. The photoelectrochemical results reflected the enhanced charge carrier separation in WO 3 ·H 2 O/Pd/CdS, and the photocatalytic H 2 evolution confirmed the highly efficient Z-scheme charge transfer in this ternary photocatalyst. Therefore, the WO 3 ·H 2 O/Pd/CdS ternary heterostructures possess distinct advantages of extended light harvesting region, spatial separation of electron and holes, and elevated redox power, which synergistically contribute to the superior photocatalysis. The Pd NPs sandwiched between WO 3 ·H 2 O and CdS acted as not only an electron mediator to facilitate the interfacial charge separation but also a cocatalyst to accelerate the selective oxidation of benzylamine. This work demonstrates a rational design of highly efficient Z-scheme photocatalysts and presents some revelations about the photocatalytic mechanism for selective organic transformations.
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Zimo Lou,Jiang Xu,Jiasheng Zhou,Kunlun Yang,Zhen Cao,Yizhou Li,Yuanli Liu,Liping Lou,Xinhua Xu
Atomic H* has been regarded as the key active species for the electrocatalytic hydrodechlorination (ECH), and the electrode design and operation conditions are related to the atomic H* generation. However, there is limited understanding of how the operation parameters affect the atomic H* generation and utilization. Due to the fact that Pd was inefficient in water dissociation step, MnO 2 was combined with Pd to construct a novel Pd/MnO 2 /Ni foam cathode. Cyclic voltammetry confirmed that Pd/MnO 2 /Ni foam cathode with MnO 2 load of 0.51 mg cm −2 possessed the highest atomic H* generation and ECH activity. Excessive Pd load (>0.44 mg cm −2 ) was detrimental to ECH because of the side hydrogen evolution reaction (HER). Operation conditions (e.g. applied current and electrolyte concentration) would directly affect the cathode potential, which was an important indicator of the atomic H* generation. The optimal cathode potential was determined to be −0.85 V when the applied current was 10 mA in this study. The electrolyte concentration of 10–15 mM was able to provide sufficient atomic H* for ECH, while excessive input of electrolyte would favor HER but inhibit ECH. ECH at acidic and neutral/alkaline solution underwent different pathways for atomic H* generation and further affect the utilization of atomic H*. After 120 min reaction, >70% of atomic H* could be selectively used for ECH at initial pH of 4.0 and 5.0, while only ∼37% was used for ECH at initial pH of 7.0. This work correlated the reactivity of electrode with the atomic H* and cathode potential, which would provide strategies for ECH catalyst design and operation optimization.
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2019
·Vol. 27
·期 5
·5085-5096
·
IF 2.914
Li Haijie,Huang Guofu,Wang Mianmian
2,2′,4,4′-Tretrabromodiphenyl ether (BDE47) is known as a typical polybrominated diphenyl ethers (PBDEs) due to its high environmental abundance, ecological toxicity, and bioaccumulation. In this study, the influences of three typical surfactants (CTAB, SDS, and TX-100) on BDE47 solubilization and degradation by the polyanionic cellulose–stabilized Pd/Fe (PAC-Pd/Fe) nanoparticles were investigated. The results showed that BDE47 solubilities increased linearly when surfactant concentrations were above their critical micelle concentrations (CMCs), and the solubilization capacities of surfactants for BDE47 followed the order of TX-100 > CTAB > SDS. The appropriate dosages of surfactants were favorable for BDE47 degradation due to enhancing solubilization and accelerating mass transfer, while excessive surfactants inhibited BDE47 degradation due to excessive and thicker micelles formed, but still higher than no surfactant. The influences of various factors (PAC-Pd/Fe nanoparticle dosage, solution pH, and temperature) on BDE47 degradation in TX-100 solution were also tested. The results showed that BDE47 degradation followed the pseudo first-order kinetics model. The degradation rates of BDE47 increased as PAC-Pd/Fe nanoparticle dosage and temperature increased. Weak acidic condition (pH 5.5) was favorable for BDE47 degradation with 96.8% BDE47 was removed within 7.5 min, while alkaline condition (9.0) was not conducive to the degradation of BDE47. The degradation of BDE47 by PAC-Pd/Fe nanoparticles was a catalytic reductive debromination process via active H-species attack, wherein the sequential debromination was the dominant reaction. This study suggests that in the presence of moderate surfactant, PAC-Pd/Fe nanoparticles may be potentially employed to eliminate BDE47 in contaminated water.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Ruiyang Zhang,Zeai Huang,Chengjin Li,Yisu Zuo,Ying Zhou
Photocatalysis has been known as a promising technique for environmental remediation and clean energy production. However, there are two weaknesses for photocatalyst in powder form applied in the gas-phase catalysis. One is the inadequate contact of gas pollutant as well as utilization of light energy and the other one is the intricate operations for recycle. Herein, we reported a new-type monolithic Pd-embedded g-C 3 N 4 /reduced graphene oxide aerogel (Pd-g-C 3 N 4 /RGOA) photocatalyst prepared through one-pot thermal reduction method. In this case, a synergistic effect was realized, in which g-C 3 N 4 powder was uniformly dispersed on the surface of RGOA and connected with RGOA through the formation of 2D-2D π-π conjugated structure to enhance the contact of gas pollution and utilization of light energy as well as separation of charge carriers, while Pd acted as an electron sink to promote electron-hole separation and its unique electronic structure improved the gas adsorption. As a result, the obtained Pd-g-C 3 N 4 /RGOA revealed enhanced hydrogenation of CO 2 to CH 4 with a max CH 4 evolution rate of 6.4 μmol g −1 h −1 , which is 12.8-fold enhancement than that of pure g-C 3 N 4 . This study provides a fresh insight for the design of efficient monolithic photocatalyst for gas-phase catalysis.
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2018
·Vol. 148
·期 7
·2019-2029
·
IF 2.911
Liu Anqiu,Huang Zhong,Wang Xiaochen
Abstract A new method has been developed for the oxidation of glucose into gluconic acid over Pd/C catalysts under the room temperature and atmospheric pressure. The carbon support was prepared by the hydrothermal treatment of renewable glucose, thus contained abundant active oxygen species. The Pd/C catalyst showed high catalytic activity towards the oxidation of glucose into gluconic acid. A 100% glucose conversion and a 98% gluconic acid yield were attained within 2 h at 0.1 MPa and room temperature. Structural analysis showed that the Pd paricle sizes of the catalysts were in the range of 10.1–16.2 nm influenced by the loading of Pd. The structure/size study showed that the catalyst with optimal particle size of 10.9 nm exhibited the highest TOF (0.2388 mol glucose mol Pd /s). The catalyst showed no significant loss of activity after recycled for four times. Graphical Abstract
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 53
·期 21
·15064-15080
·
IF 2.993
Chen Jian,Ma Lei,Cheng Tingting,Cai Aofei,Hu Yuandong,Wu Zhijie,Liu Haiyan,Bao Xiaojun,Yuan Pei
In this work, a stable and recyclable Pd catalyst supported on N-containing silane coupling agent modified silica hollow microspheres with macroporous shells (Pd/N-SHMs) was successfully prepared and used for the selective hydrogenation of nitrile-butadiene rubber (NBR) with enhanced catalytic performance. The results showed that Pd/N-SHMs possessed small-sized and well-dispersed Pd nanoparticles (NPs) and the macroporous shells were beneficial for the diffusion of macromolecular NBR, and thus with such a catalyst, the reaction could occur under mild conditions and high hydrogenation degree (96.6%) with 100% selectivity to C=C was obtained. The prepared catalyst could be easily recycled and reused with a high efficiency. More importantly, because of the strong coordination between Pd and diamine ligands, Pd NPs could be anchored steadily over the support and only 5.0 ppm Pd residues was detected in products. This reaction was considered as pseudo-first order at high H 2 pressures, and the reaction activation energy was calculated to be as low as 18.1 kJ/mol. Our contribution is to provide an efficient and recyclable supported Pd catalyst, which may promote the development of heterogeneous catalytic systems for unsaturated macromolecular hydrogenation.
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2019
·Vol. 9
·期 7
·1009
·
IF 4.034
Juanjuan Yin,Lun Zhang,Tifeng Jiao,Guodong Zou,Zhenhua Bai,Yan Chen,Qingrui Zhang,Meirong Xia,Qiuming Peng
With development of the society, the problem of environmental pollution is becoming more and more serious. There is the urgent need to develop a new type of sustainable green material for degradable pollutants. However, the conventional preparation method is limited by conditions such as cumbersome operation, high energy consumption, and high pollution. Here, a simple method named self-reduction has been proposed, to synthesize highly efficient catalytic nitro compounds and morin self-assembled MXene-Pd nanocomposites. Palladium nanoparticles were grown in situ on MXene nanosheets to form MXene@PdNPs. MXene@PdNPs composites with different reaction times were prepared by adjusting the reduction reaction time. In particular, MXene@PdNPs20 exhibited a high catalytic effect on 4-NP and 2-NA, and the first-order rate constants of the catalysis were 0.180 s−1and 0.089 s−1, respectively. It should be noted that after eight consecutive catalytic cycles, the conversion to catalyze 4-NP was still greater than 94%, and the conversion to catalyze 2-NA was still greater than 91.8%. Therefore, the research of self-assembled MXene@PdNPs nanocomposites has important potential value for environmental management and sustainable development of human health, and provides new clues for the future research of MXene-based new catalyst materials.Keywords:nanocomposites;catalyst;MXene;self-reduction;palladium nanoparticles
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysts
·
2018
·Vol. 8
·期 10
·443
·
IF 3.465
Kai Zheng,Chao Shen,Jun Qiao,Jianying Tong,Jianzhong Jin,Pengfei Zhang
Novel magnetically recyclable Fe3O4@Pd nanoparticles (NPs) were favorably synthesized by fixing palladium on the surface of nitrogen-doped magnetic nanocomposites. These catalysts were fully characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TG), and X-ray photoelectron spectroscopy (XPS). The prepared catalyst exhibited good catalytic activity for Suzuki–Miyaura coupling reactions of aryl or heteroaryl halides (I, Br, Cl) with arylboronic acids. These as-prepared catalysts could be readily isolated from the reaction liquid by an external magnet and reused at least ten times with excellent yields achieved. In addition, using this protocol, the marketed drug crizotinib (anti-tumor) could be easily synthesized.Keywords:heterogeneous catalyst;magnetically;palladium catalysts;nitrogen-doped;Suzuki coupling;crizotinib
✓ 已验证
产品关联
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2014
·
IF 6.451
Wenju Xu,Huayu Yi,Yali Yuan,Pei Jing,Yaqin Chai,Ruo Yuan,George S. Wilson
In this work, a sensitive electrochemical aptasensor for thrombin (TB) based on synergetic catalysis of enzyme and porous [email protected] core–shell nanostructure has been constructed. With the advantages of large surface area and outstanding catalytic performance, porous [email protected] core–shell nanostructures were firstly employed as the nanocarrier for the immobilization of electroactive toluidine blue (Tb), hemin/G-quadruplex formed by intercalating hemin into the TB aptamer (TBA) and glucose oxidase (GOx). As a certain amount of glucose was added into the detection cell, GOx rapidly catalyzed the oxidation of glucose, coupling with the local generation of H 2 O 2 in the presence of dissolved O 2 . Then, porous [email protected] nanoparticles and hemin/G-quadruplex as the peroxidase mimics efficiently catalyzed the reduction of H 2 O 2 , amplifying the electrochemical signal and improving the sensitivity. Finally, a detection limit of 0.037 pM for TB was achieved. The excellent performance of the aptasensor indicated its promising prospect as a valuable tool in simple and cost-effective TB detection in clinical application.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POWER SOURCES
·
2015
·
IF 6.217
Jing Li,Panpan Zhou,Feng Li,Jianxin Ma,Yang Liu,Xueyao Zhang,Hongfei Huo,Jun Jin,Jiantai Ma
The catalytic activity of noble-metal nanoparticles (NPs) often has closely connection with their sizes and geometric shape . In the work, polyhedral NPs of palladium (Pd) with controlled sizes, shapes, and different proportions of {100} to {111} facets on the surface were prepared by a seed-mediated approach. Electrochemical experiment demonstrates that the catalytic performance of the Pd nanocubes (NCs) enclosed by {100} facets is more active than Pd octahedrons enclosed by {111} facets for the hydrogen evolution reaction (HER), which is consistent with density functional theory (DFT) calculation results. Meanwhile, with the assistance of a polyethyleneimine–reduced graphene oxide (PEI–rGO) support, the examined Pd cube/PEI–rGO 50:1 (10 wt. %) electrocatalyst presents outstanding HER activity comparable with that of commercial Pt/C catalyst. This correlation between the HER catalytic activity and surface structure will contribute to the reasonable design of Pd catalysts for HER with high efficiency and low metal loading.
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2015
·Vol. 39
·期 8
·6474-6481
·
IF 3.086
Yansheng Liu,Wei Zhang,Xinlin Li,Xuanduong Le,Jiantai Ma
In this study, Pd nanoparticles functionalized on the surface of a Fe3O4@SiO2@m-SiO2 nano-catalyst has been synthesised with accessible active sites and ultra-large surface areas. The Pd/Fe3O4@SiO2@m-SiO2 nano-catalyst can be recovered by applying an external magnetic field. The catalytic activity of Pd/Fe3O4@SiO2@m-SiO2 is tested in the catalytic reduction of 4-nitrophenol and the hydrodechlorination of 4-chlorophenol. The high catalytic activity is attributed to the well-dispersed Pd nanoparticles on the ultra-large surface of Fe3O4@SiO2@m-SiO2. Furthermore, the Pd/Fe3O4@SiO2@m-SiO2 nano-catalyst can be reused at least five times without significant loss in activity, which confirms its good stability. Therefore, the approach mentioned above that is based on core–shell structured magnetic Pd/Fe3O4@SiO2@m-SiO2 provides a useful platform for the fabrication of Pd NP based catalysts that feature easy accessibility, superior activity and convenient recovery.
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 114
·94456-94461
·
IF 3.84
Zhen Zhang,Yanzhou Jiang,Maoqiang Chi,Zezhou Yang,Ce Wang,Xiaofeng Lu
Herein, we report the fabrication of polyacrylonitrile (PAN) nanofibers supported Pd–Pt alloy nanoparticles (PAN/Pd–Pt) through a simple and reliable approach by combining an electrospinning technique and in situ reduction process. The resulting PAN/Pd–Pt membranes are composed of a well-defined fiber-like structure with uniform sizes. Pd–Pt alloy nanoparticles are well dispersed on the surface of PAN nanofibers and the composition of alloy nanoparticles can be regulated through adjusting the feed molar ratio of Na2PdCl4 and K2PtCl4. The obtained products are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) measurements. The as-prepared PAN/Pd–Pt composite exhibits a remarkable catalytic performance towards the hydrogen generation from the hydrolysis of ammonia borane (NH3BH3, AB). By tuning the composition of the alloy nanoparticles of the nanocatalyst, a turnover frequency (TOF) of 51.9 mol H2 min−1 (mol Pd–Pt alloy)−1 was achieved, much higher than Pd and Pt-based nanocatalysts. In addition, the as-prepared PAN/Pd–Pt composite nanofibers show good recycling stability, as the catalyst can be easily separated from the suspension system. The electrospun nanofiber membrane supported noble metal nanoalloy catalysts shows high potential to find applications for the development of hydrogen generation for clean energy.
✓ 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）