Papers by Author: Ling Hong Luo

Abstract: The activities of cermet catalysts composed of Ni/CeO₂-ZnO anode for steam reforming of methanol were investigated for internal reforming of solid oxide fuel cell. Ni/CeO₂-ZnO anodes with specific percentage of ceria versus zinc were fabricated by wet impregnation method. The catalysts were characterized by X-ray diffraction, Scanning electron microscope (SEM) and temperature-programmed reduction. Area specific resistance (ASR) of these anodes was also examined to prove the thermal stability of them, and possible reasons for degradation were analyzed. Furthermore, The promoting effect of zinc metals included a decrease in the reduction temperature of NiO species interacting with the support, due to the hydrogen spillover effect. It was seen that the addition of zinc metal stabilized the Ni sites in the reduced state along the reforming reaction, increasing the methanol conversions and decreasing the coke formation. The maximum power density of the single cell reached 560mW cm^-2 and 380mW cm^-2 at 750°C in hydrogen and methanol steam respectively, and the cell obtained stable output in methanol steam over an operation period of 30 h.

Abstract: The physical properties and microstructures of supporting anodes are crucial for the performances of the entire SOFCs. In this investigation, the rape pollen was developed as a novel pore-former to improve the properties of the conventional NiO–YSZ(yttria-stabilized zirconia) anode substrate of solid oxide fuel cell. The advantage of using this pore-former over the conventional ones (e.g. polymethyl methacrylate (PMMA), carbon and flour) is that this pore-former had high porosity、global pore shape and uniform pore size distribution in the anode substrates, which are beneficial for rapid transport of the fuel and byproduct. The microstructure was observed by SEM, and the porosity of anode was measured by Archimedes method. The results showed that the optimum weight percent concentration was 15%, correspondingly, porosity was 40.3%, which was suitable for supporting anodes for SOFC application. And the open-circuit voltage (OCV) as high as 1.058V was obtained ,and the maximum power densities of 0.794W/cm² was achieved at 750°C, respectively, using hydrogen as fuel and ambient air as oxidant.

Abstract: Nano-sized electrolyte of CeO₂ doped 8YSZ with 2%mol CuO (YSZDC)powders were synthesized by solid state reaction method. Powder characteristics and electrical properties was characterized by XRD,SEM and Electrochemical workstation.The results demonstrate that the as-synthesized Y_0.08Zr_0.72Ce_0.2O_1.6 (YSZDC) and Y_0.08Zr_0.72Ce_0.18Cu _0.02O_1.6-δ(YSZDC-Cu_0.02) possessed similar powder characteristics, including cubic fluorite crystalline structure.About 150 °C reduction in densification temperature of Y_0.08Zr_0.72Ce_0.18Cu_0.02O_1.6-δ was obtained when compared with Y_0.08Zr_0.72Ce_0.2O_1.6.The YSZDC-Cu_0.02 pellets sintered at 1300 °C and the YSZDC sintered at 1450 °C exhibited relative densities of 95.66% and 94.73%,respectively.Electrolyte matrixs were prepared for electrolyte-supported SOFCs(ES-SOFC) , the suspension of NiO-YSZ anode was sprayed on the electrolyte, after co-sintering at 1300°C,electrolyte matrixs and anode were well adhered each othert, without connecting pores and cracks observed. Moerover, well electricity performance were showed by YSZDC and YSZDC-Cu_0.02 at a testing temperature of 750°C,And the electrolyte conductivity didn’t decrease obviously with dopping CuO.

Abstract: Aqueous tape casting was developed to fabricate YSZ films using a cobinder. The processing parameters such as pH value, dispersant content, and binder type and content on the quality of YSZ films were investigated and optimized. The results show that at pH = ~ 9.6, the YSZ suspensions with 0.8wt% of the dispersant PAA have a good stability. The degree of pseudo-plastic and viscosity of slurry using different binders increased with the increasing of PVA content, in contrast, the degree of pseudo-plastic and viscosity decreased with the increasing of B1070 content. The density and drying shrinkage of YSZ green tape are tightly related to the different binders. The sintered density of YSZ film increased as the density of green tape increased. The green tape using PVA (30wt %) +B1070 (70wt %) cobinders was sintered at 1400 °C for 2 hours. The films of YSZ with 98.5% of theoretical density have been obtained.

Abstract: Flower-like NiO powders with nano-architectures, self-assembled nano-sheets, were synthesized using Ni (NO3)2•4H2O and urea in mix solvents of ethanol and water by homogeneous precipitation. XRD patterns showed that the NiO powders were of hexagonal structure. FESEM and TEM confirmed that the average diameter of the flower-like NiO was 10μm, and the ultra-thin nano-sheets had micro-porous structure, with the thickness less than 100nm and the size of 2μm×3μm. Specific surface area (BET) was around 130.92m2/g.

Abstract: In this paper, the sintering behavior of Ni/YSZ anode and YSZ electrolytes fabricated by aqueous tape casting were studied. This study involved tape casing of Ni/YSZ (8 mol% Y2O3 stabilized ZrO2) anode, and co-sintering of anode supports and electrolytes. At last, thickness of 140 mm (after sintering) with uniform microstructure and ~30% porosity anode and thickness of ~10 0m (after sintering) with high density (> 95%) and electrolyte were achieved.