[en] Pt/XC-72 catalysts coated with N-doped carbon (denoted as Pt/XC-72@C–N) for the electro-oxidation of methanol are prepared through a combined microwave-assisted polyol with in-situ carbonization of N-doped carbon coating process using polyvinylpyrrolidone (PVP), 1-vinyl-3-ethylimidazolium nitrate (VEIN) or 1-ethyl-3-methylimidazolium dicyanamide (EMID) ionic liquid as the N-doped carbon precursor. X-ray diffraction, energy dispersive of X-ray, transmission electron microscopy, X-ray photoelectron spectroscopy, cyclic voltammograms and accelerated aging test techniques are applied to characterize the structure and the electro-catalytic activity of the catalysts. The results show that the Pt particles with the average size of around 2.5 nm are highly dispersed in face-centered cubic crystal structure in the carbon support. The structure of the N-doped carbon coating precursor has considerable influence on the electro-catalytic performance of the catalysts. The resultant catalyst with EMID ionic liquid as the N-doped carbon source exhibits 115.9 m² g⁻¹Pt electrochemical surface area (ESA) and 0.66 A mg⁻¹Pt catalytic activity towards the electro-oxidation of methanol, which are 1.37 times the ESA and 1.35 times the catalytic activity of the PVP-derived catalyst, and 2.02 times the electrochemical surface area and 1.94 times the catalytic activity of the VEIN-derived catalyst. The appropriate amount of the EMID ionic liquid used in the catalyst synthesis process is around 10 uL for 100 mg XC-72 support so as to obtain the highest electro-catalytic activity. - Highlights: • N-doped carbon coated Pt/C catalyst is prepared for methanol electro-oxidation. • Pt/XC-72@C–N exhibits excellent electrocatalytic activity over uncoated catalysts. • Ionic liquid with anionic cyano groups is most suitable as N-doped carbon precursor. • The appropriate amount of ionic liquid for coating is around 10 μL for 100 mg carbon

[en] A highly stable perovskite cathode material, Ba_0.5Sr_0.5(Co_0.6Zr_0.2)Fe_0.2O_3-δ (BSCZF) for intermediate temperature solid-oxide fuel cells (IT-SOFCs) was synthesized via the improved EDTA-citric acid complexing technique combined with high-temperature sintering. The product was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical impedance spectra (EIS) measurements. An electrolyte-supported BSCZF/SDC/Ni-SDC fuel cell was fabricated to evaluate the performance of the material. The XRD study indicates that the sintering temperature higher than 950 deg. C is sufficient to the formation of clean single BSCZF perovskite phase. Due to the incorporation of Zr ions, BSCZF perovskite exhibit lower electrical conductivity with higher activation energy but higher structural stability than the Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ (BSCF) parent oxide. The maximum electrical conductivity of BSCZF attains 16.9 S cm^-1 at around 540 deg. C. Impedance spectra showed that the ASRs of BSCZF cathode on samaria doped ceria (Ce_0.8Sm_0.2O_1.9, SDC) electrolyte are low but are still slightly larger than those of BSCF at similar conditions. The BSCZF/SDC/Ni-SDC cell exhibited a stable output with the maximum power densities of 30, 75, 139 and 241 mW cm^-2 at 550, 600, 650 and 700 deg. C, respectively. Due to the high electrochemical performances as well as the excellent stability, BSCZF perovskite may be an attractive cathode material for IT-SOFCs.

[en] Nickel hollow fibre membranes were prepared by extruding a polymer solution containing suspended nickel (Ni) powder to green hollow fibres, which were then sintered at elevated temperature under an argon atmosphere. The hollow fibres were characterized by a scanning electron microscope (SEM), X-ray diffractometer (XRD), mercury porosimeter, gas permeation test and conductance measurements. Porous Ni hollow fibres with micron-sized pore structures can be obtained directly by sintering the green fibre at relatively lower temperatures. Heated at a higher temperature (i.e., 950 deg. C), the Ni hollow fibres became gas-tight membranes which are of great interest for hydrogen separation

[en] Yttria-stabilized zirconia (YSZ) nanotubes were synthesized by the sol-gel method using porous anodic alumina oxide (AAO) as the templates. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersion X-ray (EDX) spectrum and selected area electron diffraction (SAED) techniques were used to characterize the morphology and crystalline structure of the prepared YSZ nanotubes. The length and the diameter of the YSZ nanotubes are 50 μm and 200 nm, respectively, which are in good agreement with the dimensions of the template pores, while the wall thickness of the nanotubes depends on the impregnation time. XRD and SAED measurements indicate that the obtained YSZ nanotubes after sintering at 1073 K possess a polycrystalline structure and a cubic crystal phase. Brunauer-Emmett-Teller (BET) measurement shows that the YSZ nanotubes have a surface specific area of around 40.5 m² g^-1 that is higher than that corresponding to the YSZ nanopowders

[en] A strong local coordination structure of Pt nanoparticles (NPs) over ultra-thin CeO₂ nanowires (NWS) has been synthesized to investigate the role of CeO_2NWS on the enhancement of methanol oxidation activity. The Pt/CeO_2NWS catalyst was characterized by X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy and electrochemical tests. The results showed that Pt/CeO_2NWS exhibited 1.23 times higher activity and 1.22 times longer-time durability over a commercial 20 wt% Pt/XC-72 catalyst. To further enhance the activity of Pt/CeO_2NWS catalyst and mass transfer ability, the in situ carbonization of urea had been adopted to provide N-doped carbon doping layer and porous interconnection between CeO_2NWS network, and the resulted catalyst showed 1.38 times greater activity than undoped Pt/CeO_2NWS. It was ascribed to the pyridine-like and pyrrole-like nitrogen in N-doped carbon layers, which greatly increased the electrical conductivity of CeO_2NWS and decreased the loss of electron transfer energy, as well as the strong interaction between Pt NPs and CeO_2NWS with their anisotropy and unique pore-interconnected structure.

[en] Highlights: • A novel ensemble method named as robust boosting neural networks with random weights (RBNNRW) is proposed. • Hampel robust step is introduced for the method. • The method has marked superiorities in predictive accuracy and stability especially when outliers exist. - Abstract: Neural networks with random weights (NNRW) has been used for regression due to its excellent performance. However, NNRW is sensitive to outliers and unstable to some extent in dealing with the real-world complex samples. To overcome these drawbacks, a new method called robust boosting NNRW (RBNNRW) is proposed by integrating a robust version of boosting with NNRW. The method builds a large number of NNRW sub-models sequentially by robustly reweighted sampling from the original training set and then aggregates these predictions by weighted median. The performance of RBNNRW is tested with three spectral datasets of wheat, light gas oil and diesel fuel samples. As comparisons to RBNNRW, the conventional PLS, NNRW and boosting NNRW (BNNRW) have also been investigated. The results demonstrate that the introduction of robust boosting greatly enhances the stability and accuracy of NNRW. Moreover, RBNNRW is superior to BNNRW particularly when outliers exist.