The effect of anode support on the electrochemical performance of microtubular solid oxide fuel cells fabricated by gel-casting

Different cell configurations of anode-supported microtubular solid oxide fuel cells (mT-SOFCs) using samaria-doped ceria (SDC) as the electrolyte were fabricated. Several cells were processed varying the porosity and wall thickness (outer diameter) of NiOSDC tubular supports. Suitable aqueous slurry formulations of NiOSDC for gel-casting were prepared using agarose, as a gelling agent, and sucrose, as a pore former. The subsequent NiOSDC anode functional layer (AFL), the SDC electrolyte and the La0.6Sr0.4Co0.2Fe0.8O3-dSDC cathode were deposited by spray-coating. Pre-sintering temperatures of the supports were optimized from linear shrinkage curves, thus obtaining after co-sintering, a dense electrolyte without anode-electrolyte delamination. Electrochemical characterization of mT-SOFC cells fabricated by agarose gel-casting is reported by the first time. The cell with a support of 2.6 mm diameter, 380 mm wall thickness, an active area of 1 cm2 and added porosity, using 10 wt% sucrose, achieved a maximum power density of about 400 mW cm2 at 650 ºC

Mechanical properties of highly textured porous Ni-YSZ and Co-YSZ cermets produced from directionally solidified eutectics

It is well known that several ceramic materials develop an usual; and sometimes unique; combination of properties as a result of mixing different phases with similar expansion coefficients. Sometimes they are elastically stiff, have low thermal expansion coefficients, and are resistant to chemical attack. As this paper will show, their mechanical properties are also enhanced. Nanoindentation is used to measure the mechanical properties for each phase of NiO-YSZ and CoO-YSZ eutectics produced by the laser floating zone technique, and also the analogues Ni-YSZ and Co-YSZ cermets produced by reduction from the eutectic precursors. The different tests have been performed at 100 nm, in order to obtain an imprint lower than the size of the secondary phase and extract the hardness and Young's modulus. Moreover, several tests have been performed at 2000 nm of indentation range to obtain the response of each material. The different imprints have been visualized by Atomic Force Microscopy

Functionalization of gold nanostars with cationic ß-cyclodextrin-based polymer for drug co-loading and SERS monitoring

Gold nanostars (AuNSs) exhibit modulated plasmon resonance and have a high SERS enhancement factor. However, their low colloidal stability limits their biomedical application as a nanomaterial. Cationic ß-cyclodextrin-based polymer (CCD/P) has low cytotoxicity, can load and transport drugs more efficiently than the corresponding monomeric form, and has an appropriate cationic group to stabilize gold nanoparticles. In this work, we functionalized AuNSs with CCD/P to load phenylethylamine (PhEA) and piperine (PIP) and evaluated SERS-based applications of the products. PhEA and PIP were included in the polymer and used to functionalize AuNSs, forming a new AuNS-CCD/P-PhEA-PIP nanosystem. The system was characterized by UV–VIS, IR, and NMR spectroscopy, TGA, SPR, DLS, zeta potential analysis, FE-SEM, and TEM. Additionally, Raman optical activity, SERS analysis and complementary theoretical studies were used for characterization. Minor adjustments increased the colloidal stability of AuNSs. The loading capacity of the CCD/P with PhEA-PIP was 95 ± 7%. The physicochemical parameters of the AuNS-CCD/P-PhEA-PIP system, such as size and Z potential, are suitable for potential biomedical applications Raman and SERS studies were used to monitor PhEA and PIP loading and their preferential orientation upon interaction with the surface of AuNSs. This unique nanomaterial could be used for simultaneous drug loading and SERS-based detection

Estudio de la infiltración de niquelatos y óxido de praseodimio en sustratos porosos como electrodo de oxígeno en pilas de óxido sólido (SOC)

Resumen del trabajo presentado al XVI Congreso Nacional de Materiales, celebrado en Ciudad Real del 28 de junio al 1 de julio de 2022.N

Solid oxide fuel cells produced by atmospheric plasma spray technology: Structural and electrochemical characterization

Trabajo presentado al "International Thermal Spray Conference and Exposition" celebrado en Houston (US) del 21 al 24 de Mayo de 2012.Ceramic materials have been used in a wide range of application. One of the most innovative applications is their use to perform Solid Oxide Fuel Cells. The aim of this work is to elucidate how to obtain a complete self-assembled SOFC (supported by electrolyte) using Atmospheric Plasma Spray (APS) to spray the three different ceramic layers. One of the main problems of SOFC production is the high costs of the process that can be reduced performing the three ceramic of a SOFC by APS technology. Anode (YSZ-NiO), Cathode (LSM) and Electrolyte (YSZ) can be obtained by APS with reasonable good behavior in terms of SOFC efficient. Another problem is the three layers assembling and adhesion, the use of gradual transition layers by APS improve the adhesion and assembling of the layers. Chemical and structural characterization of the feedstock powders and obtained ceramic layers was done by Laser Scattering, XRD, SEM and Confocal microscopy and correlated with the efficiency of attained APS-SOFC components.The authors wish to thank the Generalitat de Catalunya for the financial support for this research project 2009 SGR 00390 and to project VALTEC 09‐1‐0013.Peer Reviewe

The effect of anode support on the electrochemical performance of microtubular solid oxide fuel cells fabricated by gel-casting

Different cell configurations of anode-supported microtubular solid oxide fuel cells (mT-SOFCs) using samaria-doped ceria (SDC) as the electrolyte were fabricated. Several cells were processed varying the porosity and wall thickness (outer diameter) of NiOSDC tubular supports. Suitable aqueous slurry formulations of NiOSDC for gel-casting were prepared using agarose, as a gelling agent, and sucrose, as a pore former. The subsequent NiOSDC anode functional layer (AFL), the SDC electrolyte and the La0.6Sr0.4Co0.2Fe0.8O3-dSDC cathode were deposited by spray-coating. Pre-sintering temperatures of the supports were optimized from linear shrinkage curves, thus obtaining after co-sintering, a dense electrolyte without anode-electrolyte delamination. Electrochemical characterization of mT-SOFC cells fabricated by agarose gel-casting is reported by the first time. The cell with a support of 2.6 mm diameter, 380 mm wall thickness, an active area of 1 cm2 and added porosity, using 10 wt% sucrose, achieved a maximum power density of about 400 mW cm2 at 650 ºC

Mechanical properties of highly textured porous Ni-YSZ and Co-YSZ cermets produced from directionally solidified eutectics

It is well known that several ceramic materials develop an usual; and sometimes unique; combination of properties as a result of mixing different phases with similar expansion coefficients. Sometimes they are elastically stiff, have low thermal expansion coefficients, and are resistant to chemical attack. As this paper will show, their mechanical properties are also enhanced. Nanoindentation is used to measure the mechanical properties for each phase of NiO-YSZ and CoO-YSZ eutectics produced by the laser floating zone technique, and also the analogues Ni-YSZ and Co-YSZ cermets produced by reduction from the eutectic precursors. The different tests have been performed at 100 nm, in order to obtain an imprint lower than the size of the secondary phase and extract the hardness and Young's modulus. Moreover, several tests have been performed at 2000 nm of indentation range to obtain the response of each material. The different imprints have been visualized by Atomic Force Microscopy

Stability of infiltrated cathodes using Pr2NiO4+delta precursor for low-temperature fuel cell applications

The electrochemical performance and stability of infiltrated praseodymium nickelate (PNO) as the cathode for solid oxide fuel cell (SOFC) applications was studied. PNO cathode (Pr2NiO4+δ) was infiltrated into gadolinium-doped ceria (GDC) scaffolds and tested in two different anode-supported cells with tubular geometry: i) tubular cell A with Ni-YSZ support, Ni-YSZ anode functional layer (AFL), and thin (∼7 μm) electrolyte and; ii) microtubular cell B with Ni-YSZ support, without AFL and thick (34 μm) electrolyte. Both cells were stable during 91 h and 260 h of stability testing at 650 °C and experienced a reduction in total polarization resistances. Post-mortem X-ray diffraction (XRD) analysis confirmed PNO's partial transformation into the Pr4Ni3O10 phase with higher electrical conductivity and thermal stability. Improvement in the oxygen reduction reaction was confirmed using DRT analysis. This finding confirms that PNO infiltrated into GDC scaffold can be considered a promising cathode for SOFC applications.The authors would like to acknowledge Future Energy Systems Research Initiative (grant number RES0031233) and the Climate Change and Emissions Management Corporation of Canada, and grant PID2019-107106RB-C32 funded by MCIN/AEI/10.13039/501100011033 for funding this research.Peer reviewe

Hydrogen technologies

1 figura.[EN] The interest in hydrogen technologies has grown in recent years, mainly because an economy based on hydrogen can help to solve important challenges related to the global economy of the future: energy security and climate change. Taking advantage of this momentum, more and more countries are implementing a growing number of policies related to hydrogen. Indeed, the European Hydrogen Strategy establishes hydrogen as essential drivers for the total decarbonization of the current energy system in order to achieve the EU’s commitment related to carbon neutrality by 2050. However, the successful development of the hydrogen technologies requires the collaboration of the public and private sectors to accelerate its deployment and make more competitive its implementation at large-scale. The research groups that take part of the line of work dedicated to hydrogen technologies, within the CSIC Interdisciplinary Thematic Platform PTI Mobility 2030, work in this regard, developing their investigations in several important areas related to the hydrogen technologies such as hydrogen generation, storage, distribution and uses.[ES] El interés por las tecnologías del hidrógeno ha crecido en los últimos años, principalmente porque una economía basada en el hidrógeno puede dar respuesta a los grandes desafíos de la economía global del futuro: seguridad energética y cambio climático. Aprovechando este impulso, cada vez son más los países que están implementando un número creciente de políticas en favor del hidrógeno. Prueba de ello es la Estrategia Europea del Hidrógeno que establece al hidrógeno como un elemento esencial en la descarbonización total del actual sistema energético para alcanzar el compromiso de la UE con la neutralidad de carbono en 2050. No obstante, el desarrollo exitoso de las tecnologías del hidrógeno requiere que todos los actores, incluidos los sectores público y privado, aumenten sus esfuerzos para acelerar su despliegue y hacer que su implantación a gran escala resulte competitiva. Los grupos de investigación que forman parte del área de trabajo de tecnologías del hidrógeno, dentro de la Plataforma Temática Interdisciplinar PTI Mobility 2030 del CSIC, trabajan en este sentido, desarrollando su labor en áreas tan diversas como la generación, el almacenamiento, la distribución y los usos del hidrógeno.Peer reviewe