VIVIAN VAZQUEZ THYSSEN
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Artigo IPEN-doc 28526 Enhancing the catalytic activity of lanthanum-ceria fluorite for methane conversion in SOFC2021 - VILELA, V.B.; THYSSEN, V.V.; RODRIGUES, L.N.; FONSECA, F.C.A2B2O7 compounds with tailored compositions exhibit catalytic properties in a variety of high-temperature reactions, such as oxidative coupling of methane (OCM). La2Ce2O7 performs well in OCM due to selective mobile oxygen species, and suitable alkaline sites. Doping with Ca2+ increases the alkalinity, which can considerably increase selectivity for C2 products in OCM. We have explored the combustion synthesis to obtain homogeneous Ca2+-doped La2Ce2O7 materials to use as a catalytic layer in SOFC reactors for methane direct conversion to C2. The addition of Ca2+ in the A site of La2Ce2O7 resulted in the disordered fluorite-type crystalline structure. The formation of superficial oxygen vacancies related to the active oxygen species, which may benefit the OCM reaction, was detected. Electrochemical characterization showed no significant dependence of the conductivity with Ca2+-doping.Artigo IPEN-doc 28525 Development of anode-supported solid oxide fuel cell by co-tape casting and co-sintering2021 - RODRIGUES, L.N.; MACHADO, MARINA; MORAES, L.P.R.; THYSSEN, V.V.; FONSECA, F.C.Simple and cost-effective technologies to produce solid oxide fuel cells require control of microstructure, thickness, homogeneity, and reproducibility of the functional layers. The manufacturing of a solid oxide fuel cell (SOFC) involves significant ceramic processing challenges to obtain layers with controlled microstructure. Possibly the most common technique for large-scale production of SOFCs is tape casting. In this study, YSZ electrolyte and 60NiO/YSZ anode slurries were studied for the production of half-cells deposited by the sequential tape casting technique. A co-sintering procedure was developed for the half-cells and after cathode deposition the single cells were tested.