The Experts below are selected from a list of 16233 Experts worldwide ranked by ideXlab platform

Rong Yan - One of the best experts on this subject based on the ideXlab platform.

  • development of a supported tri Metallic Catalyst and evaluation of the catalytic activity in biomass steam gasification
    Bioresource Technology, 2009
    Co-Authors: Bo Xiao, Rong Yan
    Abstract:

    Abstract A supported tri-Metallic Catalyst (nano-Ni–La–Fe/γ-Al2O3) was developed for tar reduction and enhanced hydrogen production in biomass steam gasification, with focuses on preventing coke deposition and sintering effects to lengthen the lifetime of developed Catalysts. The Catalyst was prepared by deposition–precipitation method and characterized by various analytical approaches. Following that, the activity of Catalysts in biomass steam gasification was investigated in a bench-scale combined fixed bed reactor. With presence of the Catalyst, the content of hydrogen in gas products was increased to over 10 vol.%, the tar removal efficiency reached 99% at 1073 K, and more importantly the coke deposition on the Catalyst surfaces and sintering effects were avoided, leading to a long lifetime of Catalysts.

  • Hydrogen-rich gas production by steam gasification of palm oil wastes over supported tri-Metallic Catalyst
    International Journal of Hydrogen Energy, 2009
    Co-Authors: Yanfang Yin, Xuanming Zhang, Jianjun Liu, Rong Yan
    Abstract:

    The catalytic steam gasification of palm oil wastes for hydrogen-rich gas production was experimentally investigated in a combined fixed bed reactor using the newly developed tri-Metallic Catalyst. The results indicated that the supported tri-Metallic Catalyst had greater activity for the cracking of hydrocarbons and tar in vapor phase and higher hydrogen yield than the calcined dolomite in catalytic steam gasification of palm oil wastes. A series of experiments have been performed to explore the effects of temperature, steam to biomass ratio (S/B) and biomass particle size on gas composition, gas yield, low heating value (LHV) and hydrogen yield. The experiments demonstrated that temperature was the most important factor in this process; higher temperature contributed to higher hydrogen production and gas yield, however, it lowered gas heating value. Comparing with biomass catalytic gasification, the introduction of steam improved gas quality and yield, the optimal value of S/B was found to be 1.33 under the present operating condition. It was also shown that a smaller particle size was more favorable for gas quality and yield. However, the LHV of fuel gas decreased with the increasing S/B ratio and the decreasing biomass particle size.

F. Beuneu - One of the best experts on this subject based on the ideXlab platform.

  • Nucleation of single wall carbon nanotubes of various chiralities
    Solid State Communications, 2012
    Co-Authors: F. Beuneu
    Abstract:

    A simple model for the nucleation and growth of single wall carbon nanotubes from a graphene sheet at the surface of a Metallic Catalyst saturated in carbon is developed. It enables to predict the geometry and energy of tube embryos of all possible chiralities, as well as the way that they can grow. It is shown that armchair-like chiralities are energy preferred for geometrical reasons. This result is discussed and compared to experimental literature. © 2012 Elsevier Ltd. All rights reserved.

Yongnian Dai - One of the best experts on this subject based on the ideXlab platform.

  • synthesis and photoluminescence property of silicon carbide nanowires via carbothermic reduction of silica
    Nanoscale Research Letters, 2010
    Co-Authors: Xiaogang Luo, Yang Zhou, Dachun Liu, Bin Yang, Yongnian Dai
    Abstract:

    Silicon carbide nanowires have been synthesized at 1400 °C by carbothermic reduction of silica with bamboo carbon under normal atmosphere pressure without Metallic Catalyst. X-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy and Fourier transformed infrared spectroscopy were used to characterize the silicon carbide nanowires. The results show that the silicon carbide nanowires have a core–shell structure and grow along direction. The diameter of silicon carbide nanowires is about 50–200 nm and the length from tens to hundreds of micrometers. The vapor–solid mechanism is proposed to elucidate the growth process. The photoluminescence of the synthesized silicon carbide nanowires shows significant blueshifts, which is resulted from the existence of oxygen defects in amorphous layer and the special rough core–shell interface.

Yucheng Wu - One of the best experts on this subject based on the ideXlab platform.

  • Perovskite chromates cathode with resolved and anchored nickel nano-particles for direct high-temperature steam electrolysis
    Journal of Power Sources, 2014
    Co-Authors: Shanshan Xu, Dehua Dong, Yan Wang, Winston Doherty, Yucheng Wu
    Abstract:

    Abstract Doped lanthanum chromates are now commonly used to prepare composite cathodes for direct steam electrolysis. However, the limitation of electrochemical performances and cell current efficiency by insufficient electro-catalytic activity is a major challenge. This paper reports the use of reversibly exsolved catalytic Metallic Ni nano-particles on A-site deficient and B-site excess perovskite (La0.75Sr0.25)0.95(Cr0.8Ni0.2)0.95Ni0.05O3−δ (LSCNNi), in order to achieve an activity-enhanced composite cathode via high-temperature reduction under reducing atmospheres. The electrical properties of the ceramic are investigated methodically and correlated with the performances of the composite electrodes in symmetric and electrolysis cells. XRD, SEM, EDS and XPS results, confirm that the exsolution or dissolution of nano Metallic Catalyst is reversible in redox treatment cycles. The Faradic efficiency reaches approximately 80% for the LSCNNi cathode with the flow of 5%H2/Ar. Ultimately, the unified effect of Metallic Catalyst and redox-stable ceramic produce striking redox stability as well as electrochemical performances of the titled composite cathode. The results signify that the composite cathode with exsolved nickel nano-particles, is a good potential fuel electrode for direct steam electrolysis in an oxygen-ion conducting solid oxide electrolyzer.

  • high performance fuel electrodes based on nbti0 5m0 5o4 m ni cu with reversible exsolution of the nano Catalyst for steam electrolysis
    Journal of Materials Chemistry, 2013
    Co-Authors: Shisong Li, Yucheng Wu
    Abstract:

    This paper investigates potential fuel electrode materials NbTi0.5M0.5O4 (M = Ni, Cu) for solid oxide steam electrolysers. Efficient catalytic Metallic Ni and Cu nanoparticles are exsolved and anchor onto the surface of the highly electronically conducting material Nb1.33Ti0.67O4, forming an enhanced composite fuel electrode in the in situ reduction. The XRD, SEM, EDS and XPS results together confirm that the exsolution or dissolution of the nanoMetallic Catalyst is completely reversible in the redox cycles. The electrical properties of the reduced NbTi0.5M0.5O4 ceramic fuel electrode is systematically investigated and correlated to the electrochemical performance of the composite fuel electrodes in symmetric cells or electrolysis cells. The synergetic effect of the Metallic Catalyst and ceramic fuel electrode leads to the excellent stability as well as the superior performance of the direct steam electrolysis without a flow of reducing gas over the composite fuel electrodes. The Faradic efficiencies of the steam electrolysis reach 95% and 97% for the Ni- and Cu-enhanced fuel electrodes on flowing reducing gas over the fuel electrodes, respectively, however, comparable performance is achieved for the direct steam electrolysis with Ni- and Cu-enhanced fuel electrodes without flowing reducing gas over the composite fuel electrodes.

Jigang Wang - One of the best experts on this subject based on the ideXlab platform.

  • field emission property of self purification sic sio x coaxial nanowires synthesized via direct microwave irradiation using iron containing Catalyst
    Electronic Materials Letters, 2017
    Co-Authors: Qing Zhou, Yongzhi Yu, Shan Huang, Jiang Meng, Jigang Wang
    Abstract:

    SiC/SiOx coaxial nanowires were rapidly synthesized via direct microwave irradiation in low vacuum atmosphere. During the preparation process, only graphite, silicon, silicon dioxide powders were used as raw materials and iron-containing substance was employed as Catalyst. Comprehensive characterizations were employed to investigate the microstructure of the products. The results showed that a great quantity of coaxial nanowires with uniform sizes and high aspect ratio had been successfully achieved. The coaxial nanowires consist of a silicon oxide (SiOx) shell and a β-phase silicon carbide (β-SiC) core that exhibited in special tube brush like. In additional, nearly all the products were achieved in the statement of pure SiC/SiOx coaxial nanowires without the existence of Metallic Catalyst, indicating that the self-removal of iron (Fe) Catalyst should be occurred during the synthesis process. Photoluminescence (PL) spectral analysis result indicated that such novel SiC/SiOx coaxial nanowires exhibited significant blue-shift. Besides, the measurement results of field-emission (FE) demonstrated that the SiC/SiOx coaxial nanowires had ultralow turn-on field and threshold field with values of 0.2 and 2.1 V/μm, respectively. The hetero-junction structure formed between SiOx shell and SiC core, lots of emission sites, as well as clear tips of the nanowires were applied to explain the excellent FE properties. Open image in new window