Influence of the Processing Method on the Quality of the Protective Coatings for SOFC Applications

International audienceProtective layers for Solid Oxide Fuel Cells (SOFC) interconnects (IC) were developed. The contacting layers are made of La0.8Sr0.2Mn0.5Co0.5O3 (LSMC) and were prepared by wet powder spraying. In order to avoid IC oxidation and a dramatic increase of ASR, MnCo2O4 spinel protective coatings were processed either by Atmospheric Plasma Spraying (APS) or by a Metal Organic route (MO). The influence of the processing method of these layers on the resistance of their assembly with an IC was investigated on Crofer22APU and F17TNb substrates. The measured ASR is stable after about one hundred hours. Their efficiency in Single Repeated Unit (SRU) configuration was also investigated. The MO process gave the thinnest layer, thereby the lowest resistance. The APS process gives thicker and denser layers, thus preventing completely the chromium diffusion through the cathode, but a slightly higher resistance is observed

Monitoring the degradation of a solid oxide fuel cell stack during 10,000h via electrochemical impedance spectroscopy

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Potential role for triglycerides in signal transduction

AbstractWe previously reported that endothelin-1 or platelet-derived growth factor promoted in aortic smooth muscle cells a rapid hydrolysis of 1-O-alkyl-2-acyl-sn-glycero-3-phosphoethanolamine (alkyl-PE) which was immediately converted into 1-O-alkyl-2,3-diacyl-sn-glycerol (alkyl-TG) within 5 s or 60 s respectively [C. Comminges et al. (1996) Biochem. Biophys. Res. Commun. 220, 1008–1013 and C. Comminges et al. (1997) Biochim. Biophys. Acta 1355, 69–80]. In this study, we show that this alkyl-PE hydrolysis is triggered by a transient activation of a specific phospholipase C (PLC) regulated by pertussis toxin-sensitive heterotrimeric G-proteins. Moreover, this PLC can be triggered through a Ca2+ influx depending on L-type Ca2+ channel activation, as suggested by the use of a specific ‘activator’ S(−)-BayK 8644 and of selective inhibitors such as nimodipine. Interestingly, low concentrations (10−8–10−7M) of alkyl-TG block the opening of L-type Ca2+ channels, whereas identical concentrations of DG do not alter L-type Ca2+ channels. This study thus unravels a hitherto unrecognized signaling pathway generating alkyl-TG as a novel lipid second messenger, potentially acting as a negative feedback regulator of L-type Ca2+ channels

Three dimensionally ordered mesoporous hydroxylated Ni x Co 3−x O 4 spinels for the oxygen evolution reaction: on the hydroxyl-induced surface restructuring effect

International audienceMesoporous nickel cobaltites synthesized using a nanocasting technique show high OER activity after surface modifications induced by potential cycling

Platinum Supported Catalysts: Predictive CO and H 2 Chemisorption by a Statistical Cuboctahedron Cluster Model

International audienceChemisorption of probe molecules such as hydrogen and carbon monoxide on the surface of Pt particles is the most common chemical technique used to estimate the crucial parameters of metal catalysts, namely the dispersion (D), the particle size (d), and the metallic specific surface area (SPt). However, it remains a controversy concerning the stoichiometry of adsorbate per surface metal atom, leading to an inaccurate estimation of D, d, and SPt. A model describing the statistics of the surface atoms and sites on perfect cuboctahedron clusters was developed to assess values of D, d, and SPt, assuming the most favorable adsorption sites based on density functional theory (DFT) calculation of the literature. This model successfully predicted the experimental values of D, d, and SPt determined from H or CO chemisorption data, and it allowed providing a set of simple equations for the accurate determination of these parameters from chemisorption experiments on Pt

Electrochemically induced surface modifications of mesoporous spinels (Co3O4-d, MnCo2O4-d, NiCo2O4-d) as the origin of the OER activity and stability in alkaline medium

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Co3O4/rGO Catalysts for Oxygen Electrocatalysis: On the Role of the Oxide/Carbon Interaction

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