APPLIED CATALYSIS A-GENERAL
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2023
·
IF 5.5
Huanyu Zhao,Yurong He,Xiaochen Wang,Jie He,Anqiu Liu,Zehui Zhang
Selective hydrogenation of nitriles is a feasible route to synthesize primary amines. While highly desirable, conducting the synthesis under mild conditions is challenging. We report non-precious zinc and aluminum oxides supported Ni catalysts (Ni/ZnAlO x ) facilely prepared by calcination and reduction of NiZnAl layered double hydroxide (LDH) precursors. The optimized Ni/ZnAlO x -600 catalyst demonstrates great activity towards the selective hydrogenation of nitriles to primary amines. Proper-size metallic nickel provides the hydrogenation centers, and the presence of Ni-Zn alloys indicates strong metal-support interactions, which can produce electron-deficient nickel species and enhances the chemisorption of the C N bonds on the catalyst surface. The introduction of Zinc provides strong Lewis acid sites which also contribute to the catalytic activity. Based on the catalyst characterizations and control experiments, a plausible mechanism is proposed. This catalyst shows good stability and is conducive to the transformation of a variety of aromatic and aliphatic substrates, demonstrating potential application prospects.
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Nanoscale
·
2023
·Vol. 15
·期 18
·8255-8269
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IF 6.7
Huanhuan Wang,Qi Qu,Jiangshan Gao,Yan He
Herein, Fe3O4@MnO2@Ni–Co/C composites derived from PBAs were successfully fabricated. Firstly, Ni–Co Prussian blue analogues (Ni–Co PBAs) were used as precursors to derive a carbon layer on their surface by annealing treatment and subsequently translated into MnO2@Ni–Co/C nanocubes after hydrothermal reactions. Fe3O4@MnO2@Ni–Co/C composites were finally obtained after depositing Fe3O4 nanoparticles through the annealing process. Their electromagnetic wave (EMW) absorption performance apparently enhanced, thanks to the excellent impedance matching and strong attenuation derived from the synergy between the dielectric loss and the magnetic loss. In particular, the minimum reflection loss (RLmin) of Fe3O4@MnO2@Ni–Co/C reached −41.2 dB with a thickness of 4.0 mm and the effective absorption bandwidth (EAB) reached 7.1 GHz with a thickness of 2.0 mm. Therefore, the results could be significant for synthesizing EMW absorbers with excellent performance, a broad bandwidth, strong absorption, thin thickness and light weight.
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PubMed
高影响因子
Nanomaterials
·
2023
·Vol. 13
·期 1
·211
·
IF 5.3
Juanjuan Zhou,Wenying Zhou,Mengxue Yuan,Xinbo Dong,Jiebing Zhang,Xuejiao Zhang,Yanqing Zhang,Xiaolong Chen,Yanrong Chen,Xiangrong Liu
An insulating shell on the surface of conductive particles is vital for restraining the dielectric loss and leakage current of polymer composites. So as to inhibit the enormous loss and conductivity of pristine nickel (Ni)/poly(vinylidene fluoride)(PVDF) composites but still harvest a high dielectric permittivity (εr) when filler loading approaches or exceeds the percolation threshold (fc), pristine Ni particles were covered by a layer of titanium dioxide (TiO2) shell via a sol–gel approach, and then they were composited with PVDF. The impacts of the TiO2coating on the dielectric performances of the Ni/PVDF composites were explored as a function of the filler concentration, the shell thickness and frequency. In addition, the dielectric performances were fitted using the Havriliak–Negami (H–N) equation in order to further understand the TiO2shell’s effect on polarization mechanism in the composites. The Ni@TiO2/PVDF composites exhibit highεrand enhanced breakdown strength (Eb) but remarkably suppressed loss and conductivity when compared with pristine Ni/PVDF because the TiO2shell can efficiently stop the direct contact between Ni particles thereby suppressing the long–range electron transportation. Further, the dielectric performances can be effectively tuned through finely adjusting the TiO2shell’ thickness. The resulting Ni@TiO2/PVDF composites with highεrandEbbut low loss show appealing applications in microelectronics and electrical fields.Keywords:dielectric properties;metal;core–shell structure;polymer composites
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JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2019
·
IF 1.479
Yong Zhang,Zhishan Bai,Wenqiang Luo,Linlin Zhai,Bingjie Wang,Xiaohu Kang,Jieqiong Zong
In this paper, a selective nickel ions chelating adsorbents (Ni-CMCS) were prepared based on carboxymethyl chitosan by ion imprinting technique. Scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) were used to investigate their physicochemical properties. Brunauer-Emmett-Teller (BET) analysis showed that the BET surface area of Ni-CMCS had a significant increase after ion imprinting process. The effects of pH value, contact time and initial concentration of Ni(II) were studied. The adsorption kinetics were investigated, which indicated that Ni-CMCS was better fitted with pseudo-second-order kinetic model (R2 = 0.9991) with film diffusion process as rate controlling step. The adsorption isotherms study indicated that Langmuir model matched better with the experimental data for Ni-CMCS (R2 = 0.9617). Besides, the maximum adsorption capacity calculated from the Langmuir equation was 82.78 mg g−1. Moreover, the selectivity experiment suggested that Ni-CMCS had good selectivity in the presence of Co(II), Mn(II), or Cd(II). After used four cycles, Ni-CMCS kept great adsorption capacity.
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Nano Research
·
2019
·Vol. 12
·期 4
·869-875
·
IF 8.515
Long Yan,Li Jian,Wu Lanlan,Wang Qishun,Liu Yu,Wang Xiao,Song Shuyan,Zhang Hongjie
The Pt-Ni nanoframe catalysts have attracted great interest owing to their unique electronic structure and excellent catalytic performance. However, the stability of the tenuous edges of nanoframe-structures is dissatisfactory and their universal applications in catalytic market beyond electrocatalytic reactions are yet to be tapped and explored. Herein, we developed a new core@shell structured Pt-Ni nanoframe@CeO 2 (Pt-Ni NF@CeO 2 ) composite via etching the Ni from inhomogeneous Pt-Ni rhombic dodecahedra (Pt-Ni RD) by cerium(III) acetate hydrate (Ce(OAc) 3 ). In this path, Pt-Ni RD was used as self-sacrificial template, while the Ce(OAc) 3 serves as the provider of the Ce 3+ source and OH − for the formation of CeO 2 shell, etchant of Pt-Ni RD, and the surface modification agent. By this way, the etching of Pt-Ni RD and the formation of the CeO 2 shell are simultaneously proceeded to form the final Pt-Ni NF@CeO 2 in one step. The obtained Pt-Ni NF@CeO 2 exhibits strong interfacial charge transfer interaction between Pt-Ni NF core and CeO 2 shell even without reduction treatment, leading to enhanced catalytic activity in the hydrogenation of phenylacetylene. After introduction of trace silver, the Pt-Ni-Ag 4.9 NF@CeO 2 achieves remarkable catalytic performance for the selective conversion of phenylacetylene to styrene: high conversion (100%), styrene selectivity (86.5%), and good stability. It reveals that encapsulation noble metal nanoframes into metal oxide to form core@shell structured hybrids will indeed enhance their stability and catalytic properties. Particularly, this work expends the application of noble metal nanoframes materials to hydrogenation reactions.
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高影响因子
Results in Physics
·
2019
·
IF 3.042
Baosong Li,Dandan Li,Tianyong Mei,Weiwei Zhang
Ni-W/ZrO 2 -CeO 2 composite coating has been fabricated via pulse electrodeposition. The structure, morphology, composition and the operating parameters of the nanocomposite coating were evaluated and optimized for the enhanced hardness and corrosion resistance. It illustrated that the deposited coatings are dense, crack-free with nodular or granular structure. The average current density of 4–6 A dm −2 , duty cycle of 70% is beneficial to the finer structure and higher content of nanoparticles in deposits. The average roughness, crystallite size and growth rate of the composite coating was examined. The hardness as a function of duty cycle, current density and deposition time were investigated. The optimal parameters for the improved performance of the composites were given. It was illustrated that the reinforcing particle phase had been uniformly co-deposited in the coating. The embedded ZrO 2 and CeO 2 particles could enhance the corrosion resistance and hardness of Ni-W metallic matrix. Ni-W/ZrO 2 -CeO 2 nanocomposite coatings possess higher performance in aggressive environment and exhibit great application values.
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Micro & Nano Letters
·
2019
·Vol. 14
·期 7
·749-752
·
IF 0.975
Li Hong Qian,Xiao Cai Liang,Hua lan Zhou
The Ni(OH) 2 /NiOOH nanoparticles (NPs) electrodeposited on a glassy carbon electrode (GCE) in Ni(NO 3 ) 2 and NH 3 ·H 2 O aqueous solution for the electrode materials. Then the nickel hydroxide/oxyhydroxide acetate was formed in acetate solution. The effects of deposition conditions such as the concentration of Ni(NO 3 ) 2 solution, the number of sedimentary cycles, the concentration of acetate in the soaking liquid and the soaking time are discussed in detail. The electrochemical properties of the material have been investigated by cyclic voltammetry, Tafel curve, EIS and amperometric i–t curve techniques. The result displays excellent electrocatalytic activity towards the electrocatalytic oxidation of urea in alkaline solution. Furthermore, the modified electrode for oxidation reaction has the advantages of simple preparation, good electrochemical properties and stabilisation.
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高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 17
·10601-10609
·
IF 10.733
Wen-Chao Hu,Yi Shi,Yue Zhou,Chao Wang,Muhammad Rizwan Younis,Jie Pang,Chen Wang,Xing-Hua Xia
Water splitting for the oxygen evolution reaction (OER) through electrocatalysis holds significant promise for energy conversion. However, its real application is yet hindered owing to the lack of efficient electrocatalysts. Herein, we propose a plasmon activation approach for the acceleration of the OER on a Au nanorod–2D ultrathin metal–organic framework (NiCo-MOF) hybrid. The plasmon-generated hot holes of Au nanorods (AuNRs) can be injected into the nickel active sites of the OER catalyst, significantly increasing the generation of high valence Ni* active species in NiCo-MOFs with better matched energy levels for the OER, in turn decreasing the OER activation energy. Thus, excellent OER performance of the NiCo-MOFs under surface plasmon resonance of AuNRs is achieved with an overpotential of 240 mV at a current density of 10 mA cm−2 and a Tafel slope of 69 mV dec−1, which is much better than that of the reported catalysts. This finding highlights the importance of noble metal LSPR in facilitating the OER performance of MOFs and opens up a new avenue for improving the intrinsic electrocatalytic activity of pristine MOFs.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2019
·
IF 3.375
Fuxiang Feng,Li Wang,Xiangwen Zhang,Qingfa Wang
Ultrathin Ni/ZSM-5 nanosheet catalysts with different acid concentrations, B/L (Brønsted/Lewis acid sites) ratios, and nanosheet thicknesses are designed for the hydroconversion of oleic acid into aviation-fuel-range alkanes (AFRAs). The role of acid concentration/distribution and nanosheet thickness was investigated. High acid concentration enhances the hydrodeoxygenation (HDO) reaction and intrinsic deoxygenation activity because of the synergistic effect between acid sites and metal sites. The selective cracking reaction can be enhanced by tailoring nanosheet thickness and acid distribution. The thin nanosheet favors isomerization, the selective cracking reaction, as well as the generation of central branched isomers. External acid sites dominate the primary cracking and central C–C cracking of the deoxygenated products, but internal acid sites promote the deeper cracking and terminal C–C cracking. Formation of aromatics is thoroughly suppressed at low reaction temperature (≤533 K). A high AFRA yield of 41.4% is achieved over the 3 nm nanosheet catalyst with Si/Al = 300 and B/L = 0.18.
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JOURNAL OF POWER SOURCES
·
2019
·
IF 7.467
Zhiyu Shao,Jing Sun,Niankun Guo,Feng He,Keke Huang,Fuli Tian,Qin Wang
Designing highly active and low-cost electrocatalysts towards oxygen evolution reaction has ignited much interest in recent years. Thereby, rational design of those catalysts is an urgent topic that must be addressed. Herein, an effective strategy is demonstrated to be beneficial to the formation of hierarchical nitride phosphide hybrid with abundant oxygen vacancies . This hybrid catalyst exhibits an excellent OER catalytic performance, as demonstrated by an ultralow Tafel slope of 41 mV·dec −1 and an overpotential of 290 mV at 10 mA cm −2 in 1.0 M KOH solution, which is superior to those of the pure nitride, phosphide, and the commercial IrO 2 catalysts. The outstanding catalytic performance can be attributed to the specific heterojunction structure, accessible active sites, and abundant oxygen vacancies, which can facilitate the charge transport and the release of the O 2 bubbles. This study not only provides a facile strategy for constructing surface oxygen vacancies onto phosphide/nitride hybrid, but also exhibits an insight into the nature of hierarchical electrocatalyst with multiple active sites.
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Journal of Environmental Chemical Engineering
·
2019
·
IF 0
Fujin Sun,Qihui Zeng,Wen Tian,Yingming Zhu,Wei Jiang
Silver oxide is a high-performance visible-light-driven nanoparticle photocatalyst. However, its high cost and difficult recovery limit its wide application. Constructing a magnetic composite is a smart strategy to effectively utilize nanoparticle photocatalysts with acceptable performance maintenance. In this study, three magnetic ferrite supports, that is, CoFe 2 O 4 , ZnFe 2 O 4 , and NiFe 2 O 4 , were used as support to load Ag 2 O and construct Ag 2 O/MFe 2 O 4 composites to lower the Ag consumption and intensify the recovery rate. The photoactivity, stability, and magnetic recovery of the three composite magnetic photocatalysts were evaluated by using four typical organics. The results of the batch experiment confirm that Ag 2 O/MFe 2 O 4 (60%) possesses a good photoactivity and stability. However, Ag 2 O/ZnFe 2 O 4 exhibits a better photoactivity and higher magnetic recovery based on cycling during the semi-continuous process. The ferrites are inert for photocatalysis process without significant effect on Ag 2 O photocatalytic performance, but increase the surface area and improve the recovery rate as magnetic composite carriers.
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GREEN CHEMISTRY
·
2019
·Vol. 21
·期 3
·606-613
·
IF 9.405
Zhenbing Xie,Bingfeng Chen,Haoran Wu,Mingyang Liu,Huizhen Liu,Jianling Zhang,Guanying Yang,Buxing Han
Transformation of biomass or biomass-based feedstocks into fuels or valuable chemicals is of great importance for the sustainable development of our society. Mesoporous Al2O3–ZrO2 with different Al : Zr molar ratios was prepared by the sol–gel method, and Cu–Ni/Al2O3–ZrO2 catalysts were fabricated by the impregnation method. The catalytic performances of the bifunctional catalysts were studied in the selective hydrogenation of levulinic acid (LA) into 2-methyltetrahydrofuran (MTHF). It was demonstrated that both Cu : Ni and Al : Zr ratios affected the selectivity to MTHF significantly. The bimetallic catalysts Cu–Ni/Al2O3–ZrO2 containing 10 wt% Ni and 10 wt% Cu gave 99.8% MTHF selectivity at full conversion of LA when the Al : Zr ratio was 9 : 1. The outstanding catalytic performance of the catalyst is related to the mesoporous structure, the acidic properties of the support and the synergistic effect between Cu and Ni. The catalyst could be reused five times without a considerable loss of catalytic activity and selectivity.
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