In Situ Raman Characterization of SOFC Materials in Operational Conditions: A Doped Ceria Study

[EN] The particular operational conditions of electrochemical cells make the simultaneous characterization of both structural and transport properties challenging. The rapidity and flexibility of the acquisition of Raman spectra places this technique as a good candidate to measure operating properties and changes. Raman spectroscopy has been applied to well-known lanthanide ceria materials and the structural dependence on the dopant has been extracted. The evolution of Pr-doped ceria with temperature has been recorded by means of a commercial cell showing a clear increment in oxygen vacancies concentration. To elucidate the changes undergone by the electrolyte or membrane material in cell operation, the detailed construction of a homemade Raman cell is reported. The cell can be electrified, sealed and different gases can be fed into the cell chambers, so that the material behavior in the reaction surface and species evolved can be tracked. The results show that the Raman technique is a feasible and rather simple experimental option for operating characterization of solid-state electrochemical cell materials, although the treatment of the extracted data is not straightforward.This research was funded by the Spanish Government (IJCI-2017-34110, RTI2018-102161 and SEV-2016-0683 grants).Solís, C.; Balaguer Ramirez, M.; Serra Alfaro, JM. (2020). In Situ Raman Characterization of SOFC Materials in Operational Conditions: A Doped Ceria Study. Membranes. 10(7):1-16. https://doi.org/10.3390/membranes10070148S116107Maher, R. C., Duboviks, V., Offer, G. J., Kishimoto, M., Brandon, N. P., & Cohen, L. F. (2013). Raman Spectroscopy of Solid Oxide Fuel Cells: Technique Overview and Application to Carbon Deposition Analysis. Fuel Cells, 13(4), 455-469. doi:10.1002/fuce.201200173Cheng, Z., Wang, J.-H., Choi, Y., Yang, L., Lin, M. C., & Liu, M. (2011). From Ni-YSZ to sulfur-tolerant anode materials for SOFCs: electrochemical behavior, in situ characterization, modeling, and future perspectives. Energy & Environmental Science, 4(11), 4380. doi:10.1039/c1ee01758fLiu, M., Lynch, M. E., Blinn, K., Alamgir, F. M., & Choi, Y. (2011). Rational SOFC material design: new advances and tools. Materials Today, 14(11), 534-546. doi:10.1016/s1369-7021(11)70279-6Maher, R. C., Shearing, P. R., Brightman, E., Brett, D. J. L., Brandon, N. P., & Cohen, L. F. (2015). Reduction Dynamics of Doped Ceria, Nickel Oxide, and Cermet Composites Probed Using In Situ Raman Spectroscopy. Advanced Science, 3(1), 1500146. doi:10.1002/advs.201500146Laguna-Bercero, M. A., & Orera, V. M. (2011). Micro-spectroscopic study of the degradation of scandia and ceria stabilized zirconia electrolytes in solid oxide electrolysis cells. International Journal of Hydrogen Energy, 36(20), 13051-13058. doi:10.1016/j.ijhydene.2011.07.082Brett, D. J. L., Kucernak, A. R., Aguiar, P., Atkins, S. C., Brandon, N. P., Clague, R., … Vesovic, V. (2010). What Happens Inside a Fuel Cell? Developing an Experimental Functional Map of Fuel Cell Performance. ChemPhysChem, 11(13), 2714-2731. doi:10.1002/cphc.201000487Sheppard, N. (1982). Recent developments in the vibrational spectroscopies (infrared, Raman, electron energy loss etc.) as applied to the structural analysis of species chemisorbed on metal surfaces. Journal of Molecular Structure, 80, 163-174. doi:10.1016/0022-2860(82)87225-6Balaguer, M., Solís, C., & Serra, J. M. (2012). Structural–Transport Properties Relationships on Ce1–xLnxO2−δ System (Ln = Gd, La, Tb, Pr, Eu, Er, Yb, Nd) and Effect of Cobalt Addition. The Journal of Physical Chemistry C, 116(14), 7975-7982. doi:10.1021/jp211594dMogensen, M. (2000). Physical, chemical and electrochemical properties of pure and doped ceria. Solid State Ionics, 129(1-4), 63-94. doi:10.1016/s0167-2738(99)00318-5Balaguer, M., García-Fayos, J., Solís, C., & Serra, J. M. (2013). Fast Oxygen Separation Through SO2- and CO2-Stable Dual-Phase Membrane Based on NiFe2O4–Ce0.8Tb0.2O2-δ. Chemistry of Materials, 25(24), 4986-4993. doi:10.1021/cm4034963Degen, T., Sadki, M., Bron, E., König, U., & Nénert, G. (2014). The HighScore suite. Powder Diffraction, 29(S2), S13-S18. doi:10.1017/s0885715614000840Rietveld, H. M. (1969). A profile refinement method for nuclear and magnetic structures. Journal of Applied Crystallography, 2(2), 65-71. doi:10.1107/s0021889869006558Rodríguez-Carvajal, J. (1993). Recent advances in magnetic structure determination by neutron powder diffraction. Physica B: Condensed Matter, 192(1-2), 55-69. doi:10.1016/0921-4526(93)90108-iShannon, R. D. (1976). Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallographica Section A, 32(5), 751-767. doi:10.1107/s0567739476001551Taniguchi, T., Watanabe, T., Sugiyama, N., Subramani, A. K., Wagata, H., Matsushita, N., & Yoshimura, M. (2009). Identifying Defects in Ceria-Based Nanocrystals by UV Resonance Raman Spectroscopy. The Journal of Physical Chemistry C, 113(46), 19789-19793. doi:10.1021/jp9049457Weber, W. H., Hass, K. C., & McBride, J. R. (1993). Raman study ofCeO2: Second-order scattering, lattice dynamics, and particle-size effects. Physical Review B, 48(1), 178-185. doi:10.1103/physrevb.48.178Parayanthal, P., & Pollak, F. H. (1984). Raman Scattering in Alloy Semiconductors: «Spatial Correlation» Model. Physical Review Letters, 52(20), 1822-1825. doi:10.1103/physrevlett.52.1822Kosacki, I., Suzuki, T., Anderson, H. U., & Colomban, P. (2002). Raman scattering and lattice defects in nanocrystalline CeO2 thin films. Solid State Ionics, 149(1-2), 99-105. doi:10.1016/s0167-2738(02)00104-2McBride, J. R., Hass, K. C., Poindexter, B. D., & Weber, W. H. (1994). Raman and x‐ray studies of Ce1−xRExO2−y, where RE=La, Pr, Nd, Eu, Gd, and Tb. Journal of Applied Physics, 76(4), 2435-2441. doi:10.1063/1.357593Esther Jeyanthi, C., Siddheswaran, R., Kumar, P., Siva Shankar, V., & Rajarajan, K. (2014). Structural and spectroscopic studies of rare earths doped ceria (RELa,Sc,Yb:CeO2) nanopowders. Ceramics International, 40(6), 8599-8605. doi:10.1016/j.ceramint.2014.01.076Shirbhate, S., Nayyar, R. N., Ojha, P. K., Yadav, A. K., & Acharya, S. (2019). Exploration of Atomic Scale Changes during Oxygen Vacancy Dissociation Mechanism in Nanostructure Co-Doped Ceria: As Electrolytes for IT-SOFC. Journal of The Electrochemical Society, 166(8), F544-F554. doi:10.1149/2.1191908jesArtini, C. (2018). Rare-Earth-Doped Ceria Systems and Their Performance as Solid Electrolytes: A Puzzling Tangle of Structural Issues at the Average and Local Scale. Inorganic Chemistry, 57(21), 13047-13062. doi:10.1021/acs.inorgchem.8b02131Spanier, J. E., Robinson, R. D., Zhang, F., Chan, S.-W., & Herman, I. P. (2001). Size-dependent properties ofCeO2−ynanoparticles as studied by Raman scattering. Physical Review B, 64(24). doi:10.1103/physrevb.64.245407Zhang, F., Chan, S.-W., Spanier, J. E., Apak, E., Jin, Q., Robinson, R. D., & Herman, I. P. (2002). Cerium oxide nanoparticles: Size-selective formation and structure analysis. Applied Physics Letters, 80(1), 127-129. doi:10.1063/1.1430502Suzuki, T., Kosacki, I., Anderson, H. U., & Colomban, P. (2004). Electrical Conductivity and Lattice Defects in Nanocrystalline Cerium Oxide Thin Films. Journal of the American Ceramic Society, 84(9), 2007-2014. doi:10.1111/j.1151-2916.2001.tb00950.xDohčević-Mitrović, Z. D., Šćepanović, M. J., Grujić-Brojčin, M. U., Popović, Z. V., Bošković, S. B., Matović, B. M., … Aldinger, F. (2006). The size and strain effects on the Raman spectra of Ce1−xNdxO2−δ (0≤x≤0.25) nanopowders. Solid State Communications, 137(7), 387-390. doi:10.1016/j.ssc.2005.12.006Balaguer, M., Solís, C., & Serra, J. M. (2011). Study of the Transport Properties of the Mixed Ionic Electronic Conductor Ce1−xTbxO2−δ + Co (x = 0.1, 0.2) and Evaluation As Oxygen-Transport Membrane. Chemistry of Materials, 23(9), 2333-2343. doi:10.1021/cm103581wBalaguer, M., Solís, C., Roitsch, S., & Serra, J. M. (2014). Engineering microstructure and redox properties in the mixed conductor Ce0.9Pr0.1O2−δ+ Co 2 mol%. Dalton Trans., 43(11), 4305-4312. doi:10.1039/c3dt52167bAcharya, S. A., Gaikwad, V. M., Sathe, V., & Kulkarni, S. K. (2014). Influence of gadolinium doping on the structure and defects of ceria under fuel cell operating temperature. Applied Physics Letters, 104(11), 113508. doi:10.1063/1.4869116Zallen, R., & Conwell, E. M. (1979). The effect of temperature on libron frequencies in molecular crystals: Implications for TTF-TCNQ. Solid State Communications, 31(8), 557-561. doi:10.1016/0038-1098(79)90252-7Hart, T. R., Aggarwal, R. L., & Lax, B. (1970). Temperature Dependence of Raman Scattering in Silicon. Physical Review B, 1(2), 638-642. doi:10.1103/physrevb.1.638Lughi, V., & Clarke, D. R. (2007). Temperature dependence of the yttria-stabilized zirconia Raman spectrum. Journal of Applied Physics, 101(5), 053524. doi:10.1063/1.2697347Long, R. Q., Huang, Y. P., & Wan, H. L. (1997). Surface Oxygen Species Over Cerium Oxide and Their Reactivities with Methane and Ethane by Means ofin situConfocal Microprobe Raman Spectroscopy. Journal of Raman Spectroscopy, 28(1), 29-32. doi:10.1002/(sici)1097-4555(199701)28:13.0.co;2-gPushkarev, V. V., Kovalchuk, V. I., & d’ Itri, J. L. (2004). Probing Defect Sites on the CeO2 Surface with Dioxygen. The Journal of Physical Chemistry B, 108(17), 5341-5348. doi:10.1021/jp0311254Weber, A., & McGinnis, E. A. (1960). The Raman spectrum of gaseous oxygen. Journal of Molecular Spectroscopy, 4(1-6), 195-200. doi:10.1016/0022-2852(60)90081-3Hornés, A., Bera, P., Fernández-García, M., Guerrero-Ruiz, A., & Martínez-Arias, A. (2012). Catalytic and redox properties of bimetallic Cu–Ni systems combined with CeO2 or Gd-doped CeO2 for methane oxidation and decomposition. Applied Catalysis B: Environmental, 111-112, 96-105. doi:10.1016/j.apcatb.2011.09.022Duboviks, V., Maher, R. C., Offer, G., Cohen, L. F., & Brandon, N. P. (2013). In-Operando Raman Spectroscopy Study of Passivation Effects on Ni-CGO Electrodes in CO2 Electrolysis Conditions. ECS Transactions, 57(1), 3111-3117. doi:10.1149/05701.3111ecstDuboviks, V., Maher, R. C., Kishimoto, M., Cohen, L. F., Brandon, N. P., & Offer, G. J. (2014). A Raman spectroscopic study of the carbon deposition mechanism on Ni/CGO electrodes during CO/CO2 electrolysis. Phys. Chem. Chem. Phys., 16(26), 13063-13068. doi:10.1039/c4cp01503

Catalytic surface promotion of highly active La0.85Sr0.15Cr0.8Ni0.2O3-delta anodes for La5.6WO11.4-delta based proton conducting fuel cells

[EN] La0.85Sr0.15CrO3-delta (LSC), La0.85Sr0.15Cr0.8Ni0.2O3-delta (LSCN) and LSCN infiltrated with Ni nanoparticles were tested as anodes for symmetrical cells based on La5.6WO11.4-delta (LWO) protonic electrolyte. These chromite-based electrode materials are compatible with LWO material, in contrast to the widely used NiO. Under typical anode reducing conditions, Ni is segregated from the LSCN lattice on the grain surface as metallic Ni nanoparticles, which are proved to be compatible with LWO in reducing conditions. These Ni nanoparticles become the catalytic active sites for the H-2 oxidation reaction in proton conducing anodes and the electrode performance is substantially improved regarding to pure LSC. Ni nanoparticle infiltration further improves the catalytic promotion of the anode, reducing the polarization resistance (R-p) previously limited by low frequency surface related processes. Indeed, the R-p, values achieved for LSCN infiltrated with Ni, e.g. 0.47 Omega cm(2) at 700 degrees C, suggest the practical application of this kind of anodes in proton conducting solid oxide fuel cells (PC-SOFC). (C) 2013 Elsevier B.V. All rights reserved.Funding from European Union (FP7 Project EFFIPRO - Grant Agreement 227560), the Spanish Government (ENE2011-24761, SEV-2012-0267 and CSIC Intramural 2008801093 grants) is kindly acknowledged. The authors thank M. Fabuel for sample preparation.Solis Díaz, C.; Balaguer Ramirez, M.; Bozza, F.; Bonanos, N.; Serra Alfaro, JM. (2014). Catalytic surface promotion of highly active La0.85Sr0.15Cr0.8Ni0.2O3-delta anodes for La5.6WO11.4-delta based proton conducting fuel cells. Applied Catalysis B Environmental. 147:203-207. https://doi.org/10.1016/j.apcatb.2013.08.04420320714

Progress in Ce(0.8)Gd(0.2)O(2-delta)protective layers for improving the CO(2)stability of Ba0.5Sr0.5Co0.8Fe0.2O3-delta O2-transport membranes

[EN] Ce0.8Gd0.2O2-delta(CGO) thin films were deposited by radio frequency (RF) magnetron sputtering and deposition temperature was changed in order to optimize the microstructure and transport properties of the obtained films. Afterwards, the films were deposited on Ba0.5Sr0.5Co0.8Fe0.2O3-delta(BSCF) oxygen separation membranes as CO(2)protective layers. Oxygen permeation was finally measured by sweeping both Ar and CO2, and the obtained results were compared with the bare BSCF membrane. It was found that the oxygen permeation of the BSCF is improved by this CGO layer, with a 4-fold improvement in the oxygen permeation flux when using pure CO(2)as the sweep gas at 900 degrees C. Therefore, these CGO protective layers are a promising way for overcoming the limitations of BSCF membranes in CO2-containing environments, associated with surface competitive O-2-CO(2)adsorption and carbonation of Ba at low temperatures.Funding from the Spanish Government (RTI2018-102161, SEV-2016-0683 and IJCI-2017-34110 grants) and Generalitat Valenciana (PROMETEO/2018/006 grant) is kindly acknowledged. The support of the Servicio de Microscopia Electronica of the Universitat Politecnica de Valencia is also acknowledged.Solis Díaz, C.; Balaguer Ramirez, M.; García-Fayos, J.; Palafox, E.; Serra Alfaro, JM. (2020). Progress in Ce(0.8)Gd(0.2)O(2-delta)protective layers for improving the CO(2)stability of Ba0.5Sr0.5Co0.8Fe0.2O3-delta O2-transport membranes. Sustainable Energy & Fuels. 4(7):3747-3752. https://doi.org/10.1039/d0se00324g374737524

Absolute risk and risk factors for stroke mortality in patients with end stage kidney disease (ESKD): population-based cohort study using data linkage

INTRODUCTION: People with end-stage kidney disease (ESKD) have up to 30-fold higher risk of stroke than the general population. OBJECTIVE: To determine risk factors associated with stroke death in the ESKD population. METHODS: We identified all patients with incident ESKD in Australia (1980-2013) and New Zealand (1988-2012) from the Australian and New Zealand Dialysis and Transplant Registry (ANZDATA) registry. We ascertained underlying cause of death from data linkage with national death registries and risk factors from ANZDATA. Using a competing risks multivariable regression model, we estimated cumulative incidence of stroke and non-stroke deaths, and risk factors for stroke deaths (adjusted sub-HR, SHR). RESULTS: We included 60 823 people with ESKD. There were 941 stroke deaths and 33 377 non-stroke deaths during 381 874 person-years of follow-up. Overall, the cumulative incidence of stroke death was 0.9% and non-stroke death was 36.8% 5 years after starting ESKD treatment. The risk of stroke death was higher at older ages (SHR 1.92, 95% CI 1.45 to 2.55), in females (SHR 1.41, 95% CI 1.21 to 1.64), in people with cerebrovascular disease (SHR 2.39, 95% CI 1.99 to 2.87), with ESKD caused by hypertensive/renovascular disease (SHR 1.39, 95% CI 1.09 to 1.78) or polycystic kidney disease (SHR 1.38, 95% CI 1.00 to 1.90), with earlier year of ESKD treatment initiation (SHR 1.93, 95% CI 1.56 to 2.39) and receiving dialysis (transplant vs haemodialysis SHR 0.27, 95% CI 0.09 to 0.84). CONCLUSION: Patients with ESKD with higher risk of stroke death are older, women, with cerebrovascular disease, with hypertensive/renovascular or polycystic kidney disease cause of ESKD, with earlier year of ESKD treatment and receiving dialysis. These groups may benefit from targeted stroke prevention interventions

Boosting methane partial oxidation on ceria through exsolution of robust Ru nanoparticles

[EN] Finding sustainable routes for the transformation of CO2 into fuels and added-value chemicals is key for mitigating greenhouse gas emission. In this respect, chemical-looping reforming coupled with CO2 splitting emerges as a promising technology to produce syngas, using waste or solar heat as an energy source. It relies on metal oxides that act as redox intermediates and, thus, the stability and catalytic activity of the oxides are crucial. For that purpose, ceria has been widely used due to its superior multicyclic stability and fast CO2 splitting kinetics. However, it also presents low capacity for oxygen exchange or supply compared with other oxides and slow methane partial oxidation kinetics, which is normally improved by cationic doping or catalytic surface activation via metal impregnation. The high temperatures (900 degrees C) required for these reactions lead to catalyst deactivation over time due to sintering of metallic clusters. In order to circumvent this issue, in this work we have utilized the exsolution method to create uniformly dispersed Ru nanoparticles (ca. 5 nm) that remain anchored to the cerium oxide backbone, guaranteeing its microstructural stability and catalytic activity over prolonged cycling. We provide evidence for metallic Ru exsolution and further demonstrate the outstanding benefits of exsolved nanoparticles in the partial oxidation of methane following a chemical-loop reforming scheme, especially in the temperature range in which industrial waste heat could be used as an energy source to drive the reaction. Remarkably, at 700 degrees C surface functionalization with exsolved Ru nanoparticles enables high CO selectivity (99% versus 62% for CeO2) and about 2 orders of magnitude faster H-2 production rates. The dispersion and size of the exsolved Ru nanoparticles were maintained after a durability test of 20 chemical loops at 900 degrees C, indicating their robustness. Overall, the results presented here point towards the unique characteristics of nanoparticle exsolution for preventing agglomeration, which could find application in other catalytic or electrochemical processes for target hydrocarbon production.AJC and MB would like to acknowledge the support of Juan de la Cierva fellowships by the Spanish Ministry of Science (grant numbers FJCI-2017-33967 and IJCI-2017-34110). We acknowledge the support of the Electronic Microscopy Service of the Universitat Politecnica de Valencia.Carrillo-Del Teso, AJ.; Navarrete Algaba, L.; Laqdiem-Marin, M.; Balaguer Ramirez, M.; Serra Alfaro, JM. (2021). Boosting methane partial oxidation on ceria through exsolution of robust Ru nanoparticles. Materials Advances. 2(9):2924-2934. https://doi.org/10.1039/d1ma00044f292429342

An intracerebroventricular injection of amyloid-beta peptide (1–42) aggregates modifies daily temporal organization of clock factors expression, protein carbonyls and antioxidant enzymes in the rat hippocampus

Alzheimer disease (AD) is the most frequent form of dementia in the elderly. It is characterized by the deterioration of memory and learning. The histopathological hallmarks of AD include the presence of extracellular deposits of amyloid beta peptide, intracellular neurofibrillary tangles, neuron and synapse loss, in the brain, including the hippocampus. Accumulation of Aβ peptide causes an increase in intracellular reactive oxygen species (ROS) and free radicals associated to a deficient antioxidant defense system. Besides oxidative stress and cognitive deficit, AD patients show alterations in their circadian rhythms. The objective of this work was to investigate the effects of an intracerebroventricular injection of amyloid beta peptide Aβ(1–42) aggregates on temporal patterns of protein oxidation, antioxidant enzymes and clock factors in the rat hippocampus. Four-month-old male Holtzman rats divided into the groups control (CO) and Aβ-injected (Aβ), were maintained under 12 h-light12h-dark conditions and received water and food ad-libitum. Hippocampus samples were isolated every 6 h during a 24 h period. Our results showed daily patterns of protein carbonyls, catalase (CAT) and glutathione peroxidase (GPx) expression and activity, as well as Rorα and Rev-erbß mRNA, in the rat hippocampus. Interestingly, an intracerebroventricular injection of Aβ aggregates modified daily oscillation of protein carbonyls levels, phase-shifted daily rhythms of clock genes and had a differential effect on the daily expression and activity of CAT and GPx. Thus, Aβ aggregates might affect clock-mediated transcriptional regulation of antioxidant enzymes, by affecting the formation of BMAL1:CLOCK heterodimer, probably, as a consequence of the alteration of the redox state observed in rats injected with Aβ.Fil: Navigatore Fonzo, Lorena Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Alfaro, Mauro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Mazaferro, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Golini, Rebeca Laura Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Leporatti, Jorge. Universidad Nacional de San Luis. Facultad de Ciencias Económicas, Jurídicas y Sociales; ArgentinaFil: Della Vedova, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Ramirez, Dario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Delsouc, María Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Casais, Marilina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Anzulovich Miranda, Ana Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentin

Hydrogen production via microwave-induced water splitting at low temperature

[EN] Hydrogen is a promising vector in the decarbonization of energy systems, but more efficient and scalable synthesis is required to enable its widespread deployment. Towards that aim, Serra et al. present a microwave-based approach that allows contactless water electrolysis that can be integrated with hydrocarbon production. Supplying global energy demand with CO2-free technologies is becoming feasible thanks to the rising affordability of renewable resources. Hydrogen is a promising vector in the decarbonization of energy systems, but more efficient and scalable synthesis is required to enable its widespread deployment. Here we report contactless H-2 production via water electrolysis mediated by the microwave-triggered redox activation of solid-state ionic materials at low temperatures (<250 degrees C). Water was reduced via reaction with non-equilibrium gadolinium-doped CeO2 that was previously in situ electrochemically deoxygenated by the sole application of microwaves. The microwave-driven reduction was identified by an instantaneous electrical conductivity rise and O-2 release. This process was cyclable, whereas H-2 yield and energy efficiency were material- and power-dependent. Deoxygenation of low-energy molecules (H2O or CO2) led to the formation of energy carriers and enabled CH4 production when integrated with a Sabatier reactor. This method could be extended to other reactions such as intensified hydrocarbons synthesis or oxidation.This work was supported by the Spanish Government (RTI2018-102161, SEV-2016-0683 and Juan de la Cierva grant IJCI-2017-34110). We thank the support of the Electronic Microscopy Service of the Universitat Politecnica de Valencia.Serra Alfaro, JM.; Borras-Morell, JF.; García-Baños, B.; Balaguer Ramirez, M.; Plaza González, PJ.; Santos-Blasco, J.; Catalán-Martínez, D.... (2020). Hydrogen production via microwave-induced water splitting at low temperature. Nature Energy. 5(11):910-919. https://doi.org/10.1038/s41560-020-00720-6910919511Serra, J. M. Electrifying chemistry with protonic cells. Nat. Energy 4, 178–179 (2019).Wei, M., McMillan, C. A. & de la Rue du Can, S. Electrification of industry: potential, challenges and outlook. Curr. Sustain. Energy Rep. 6, 140–148 (2019).Malerød-Fjeld, H. et al. Thermo-electrochemical production of compressed hydrogen from methane with near-zero energy loss. Nat. Energy 2, 923–931 (2017).Schiffer, Z. J. & Manthiram, K. Electrification and decarbonization of the chemical industry. Joule 1, 10–14 (2017).Ran, J., Zhang, J., Yu, J., Jaroniec, M. & Qiao, S. Z. Earth-abundant cocatalysts for semiconductor-based photocatalytic water splitting. Chem. Soc. Rev. 43, 7787–7812 (2014).Kudo, A. & Miseki, Y. Heterogeneous photocatalyst materials for water splitting. Chem. Soc. Rev. 38, 253–278 (2009).Vøllestad, E. et al. Mixed proton and electron conducting double perovskite anodes for stable and efficient tubular proton ceramic electrolysers. Nat. Mater. 18, 752–759 (2019).Duan, C. et al. Highly efficient reversible protonic ceramic electrochemical cells for power generation and fuel production. Nat. Energy 4, 230–240 (2019).Service, R. F. New electrolyzer splits water on the cheap. Science 367, 1181 (2020).Hamzehlouia, S., Jaffer, S. A. & Chaouki, J. Microwave heating-assisted catalytic dry reforming of methane to syngas. Sci. Rep. 8, 8940 (2018).Tsukahara, Y. et al. In situ observation of nonequilibrium local heating as an origin of special effect of microwave on chemistry. J. Phys. Chem. C 114, 8965–8970 (2010).Sholl, D. S. & Lively, R. P. Seven chemical separations to change the world. Nature 532, 435–437 (2016).Eigen, J. & Schroeder, M. Redox cycling stability of Fe2NiO4/YSZ composite storage materials for rechargeable oxide batteries. Energy Storage Mater. 28, 112–121 (2020).Catalá-Civera, J. M. et al. Dynamic measurement of dielectric properties of materials at high temperature during microwave heating in a dual mode cylindrical cavity. IEEE Trans. Microw. Theory Tech. 63, 2905–2914 (2012).García-Baños, B., Reinosa, J. J., Peñaranda-Foix, F. L., Fernández, J. F. & Catalá-Civera, J. M. Temperature assessment of microwave-enhanced heating processes. Sci. Rep. 9, 10809 (2019).Campbell, C. T. & Peden, C. H. F. Oxygen vacancies and catalysis on ceria surfaces. Science 309, 713–714 (2005).Naghavi, S. S. et al. Giant onsite electronic entropy enhances the performance of ceria for water splitting. Nat. Commun. 8, 1–6 (2017).Chueh, W. C. et al. High-flux solar-driven thermochemical dissociation of CO2 and H2O using nonstoichiometric ceria. Sci. 330, 1797–1801 (2010).Bulfin, B. et al. Analytical model of CeO2 oxidation and reduction. J. Phys. Chem. C 117, 24129–24137 (2013).Geller, A. et al. Operando tracking of electrochemical activity in solid oxide electrochemical cells by using near-infrared imaging. ChemElectroChem 2, 1527–1534 (2015).Balaguer, M., Solís, C. & Serra, J. M. Structural-transport properties relationships on Ce1–xLnxO2–δ system (Ln = Gd, La, Tb, Pr, Eu, Er, Yb, Nd) and effect of cobalt addition. J. Phys. Chem. C 116, 7975–7982 (2012).Holstein, T. Studies of polaron motion. Part II. The ‘small’ polaron. Ann. Phys. (N. Y). 8, 343–389 (1959).Seki, K. & Tachiya, M. Electric field dependence of charge mobility in energetically disordered materials: polaron aspects. Phys. Rev. B 65, 1–13 (2002).Emin, D. Generalized adiabatic polaron hopping: Meyer–Neldel compensation and Poole–Frenkel behavior. Phys. Rev. Lett. 100, 166602 (2008).Bishop, S. R., Duncan, K. L. & Wachsman, E. D. Surface and bulk oxygen non-stoichiometry and bulk chemical expansion in gadolinium-doped cerium oxide. Acta Mater. 57, 3596–3605 (2009).Suzuki, T., Kosacki, I. & Anderson, H. U. Defect and mixed conductivity in nanocrystalline doped cerium oxide. J. Am. Ceram. Soc. 85, 1492–1498 (2002).Zeng, L., Cheng, Z., Fan, J. A., Fan, L. S. & Gong, J. Metal oxide redox chemistry for chemical looping processes. Nat. Rev. Chem. 2, 349–364 (2018).Liu, W., Song, M.-S., Kong, B. & Cui, Y. Flexible and stretchable energy storage: recent advances and future perspectives. Adv. Mater. 29, 1603436 (2017).Berger, C. M. et al. Development of storage materials for high-temperature rechargeable oxide batteries. J. Energy Storage 1, 54–64 (2015).Posdziech, O., Schwarze, K. & Brabandt, J. Efficient hydrogen production for industry and electricity storage via high-temperature electrolysis. Int. J. Hydrog. Energy 44, 19089–19101 (2019).Maric, R. & Yu, H. In Nanostructures in Energy Generation, Transmission and Storage (IntechOpen, 2018).Dincer, I. & Acar, C. Review and evaluation of hydrogen production methods for better sustainability. Int. J. Hydrog. Energy 40, 11094–11111 (2015).Gielen, D. Hydrogen from Renewable Power Technology Outlook for the Energy Transition (2018).Kuckshinrichs, W., Ketelaer, T. & Koj, J. C. Economic analysis of improved alkaline water electrolysis. Front. Energy Res. 5, 1 (2017).Holladay, J. D., Hu, J., King, D. L. & Wang, Y. An overview of hydrogen production technologies. Catal. Today 139, 244–260 (2009).Glenk, G. & Reichelstein, S. Economics of converting renewable power to hydrogen. Nat. Energy 4, 216–222 (2019).Marxer, D., Furler, P., Takacs, M. & Steinfeld, A. Solar thermochemical splitting of CO2 into separate streams of CO and O2 with high selectivity, stability, conversion, and efficiency. Energy Environ. Sci. 10, 1142–1149 (2017).Vogt, C., Monai, M., Kramer, G. J. & Weckhuysen, B. M. The renaissance of the Sabatier reaction and its applications on Earth and in space. Nat. Catal. 2, 188–197 (2019).Eckle, S., Anfang, H. G. & Behm, R. J. Reaction intermediates and side products in the methanation of CO and CO2 over supported Ru catalysts in H2-rich reformate gases. J. Phys. Chem. C 115, 1361–1367 (2011).Wei, Y. et al. Three-dimensionally ordered macroporous Ce0.8Zr0.2O2-supported gold nanoparticles: synthesis with controllable size and super-catalytic performance for soot oxidation. Energy Environ. Sci. 4, 2959–2970 (2011).Santos, V. P., Pereira, M. F. R., Órfão, J. J. M. & Figueiredo, J. L. The role of lattice oxygen on the activity of manganese oxides towards the oxidation of volatile organic compounds. Appl. Catal. B 99, 353–363 (2010).Hickman, D. A. & Schmidt, L. D. Production of syngas by direct catalytic oxidation of methane. Science 259, 343–346 (1993).Feng, Z. A. et al. Fast vacancy-mediated oxygen ion incorporation across the ceria-gas electrochemical interface. Nat. Commun. 5, 1–9 (2014).Flytzani-Stephanopoulos, M., Sakbodin, M. & Wang, Z. Regenerative adsorption and removal of H2S from hot fuel gas streams by rare earth oxides. Science 312, 1508–1510 (2006).Paunović, V. et al. Europium oxybromide catalysts for efficient bromine looping in natural gas valorization. Angew. Chem. Int. Ed. 56, 9791–9795 (2017).Krupka, J. Contactless methods of conductivity and sheet resistance measurement for semiconductors, conductors and superconductors. Meas. Sci. Technol. 24, 62001 (2013).Altschuler, H. M. Handbook of Microwave Measurements Vol. 2 (Polytechnic Institute Brooklyn Press, 1963).Arai, M., Binner, J. G. P. & Cross, T. E. Comparison of techniques for measuring high-temperature microwave complex permittivity: measurements on an alumina/zircona system. J. Microw. Power Electromagn. Energy 31, 12–18 (1996).López, R. & Gómez, R. Band-gap energy estimation from diffuse reflectance measurements on sol–gel and commercial TiO2: a comparative study. J. Sol.-Gel Sci. Technol. 61, 1–7 (2012).Murphy, A. B. Band-gap determination from diffuse reflectance measurements of semiconductor films, and application to photoelectrochemical water-splitting. Sol. Energy Mater. Sol. Cells 91, 1326–1337 (2007).Skorodumova, N. V. et al. Electronic, bonding, and optical properties of CeO2 and Ce2O3 from first principles. Phys. Rev. B 64, 1151081–1151089 (2001)

Absolute risk and risk factors for stroke mortality in patients with end-stage kidney disease (ESKD): population-based cohort study using data linkage

Introduction People with end-stage kidney disease (ESKD) have up to 30-fold higher risk of stroke than the general population. Objective To determine risk factors associated with stroke death in the ESKD population. Methods We identified all patients with incident ESKD in Australia (1980–2013) and New Zealand (1988–2012) from the Australian and New Zealand Dialysis and Transplant Registry (ANZDATA) registry. We ascertained underlying cause of death from data linkage with national death registries and risk factors from ANZDATA. Using a competing risks multivariable regression model, we estimated cumulative incidence of stroke and non-stroke deaths, and risk factors for stroke deaths (adjusted sub-HR, SHR). Results We included 60 823 people with ESKD. There were 941 stroke deaths and 33 377 non-stroke deaths during 381 874 person-years of follow-up. Overall, the cumulative incidence of stroke death was 0.9% and non-stroke death was 36.8% 5 years after starting ESKD treatment. The risk of stroke death was higher at older ages (SHR 1.92, 95% CI 1.45 to 2.55), in females (SHR 1.41, 95% CI 1.21 to 1.64), in people with cerebrovascular disease (SHR 2.39, 95% CI 1.99 to 2.87), with ESKD caused by hypertensive/renovascular disease (SHR 1.39, 95% CI 1.09 to 1.78) or polycystic kidney disease (SHR 1.38, 95% CI 1.00 to 1.90), with earlier year of ESKD treatment initiation (SHR 1.93, 95% CI 1.56 to 2.39) and receiving dialysis (transplant vs haemodialysis SHR 0.27, 95% CI 0.09 to 0.84). Conclusion Patients with ESKD with higher risk of stroke death are older, women, with cerebrovascular disease, with hypertensive/renovascular or polycystic kidney disease cause of ESKD, with earlier year of ESKD treatment and receiving dialysis. These groups may benefit from targeted stroke prevention interventions. This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial

Recent smell loss is the best predictor of COVID-19 among individuals with recent respiratory symptoms

In a preregistered, cross-sectional study we investigated whether olfactory loss is a reliable predictor of COVID-19 using a crowdsourced questionnaire in 23 languages to assess symptoms in individuals self-reporting recent respiratory illness. We quantified changes in chemosensory abilities during the course of the respiratory illness using 0-100 visual analog scales (VAS) for participants reporting a positive (C19+; n=4148) or negative (C19-; n=546) COVID-19 laboratory test outcome. Logistic regression models identified univariate and multivariate predictors of COVID-19 status and post-COVID-19 olfactory recovery. Both C19+ and C19- groups exhibited smell loss, but it was significantly larger in C19+ participants (mean±SD, C19+: -82.5±27.2 points; C19-: -59.8±37.7). Smell loss during illness was the best predictor of COVID-19 in both univariate and multivariate models (ROC AUC=0.72). Additional variables provide negligible model improvement. VAS ratings of smell loss were more predictive than binary chemosensory yes/no-questions or other cardinal symptoms (e.g., fever). Olfactory recovery within 40 days of respiratory symptom onset was reported for ~50% of participants and was best predicted by time since respiratory symptom onset. We find that quantified smell loss is the best predictor of COVID-19 amongst those with symptoms of respiratory illness. To aid clinicians and contact tracers in identifying individuals with a high likelihood of having COVID-19, we propose a novel 0-10 scale to screen for recent olfactory loss, the ODoR-19. We find that numeric ratings ≤2 indicate high odds of symptomatic COVID-19 (4&lt;10). Once independently validated, this tool could be deployed when viral lab tests are impractical or unavailable

The Eighteenth Data Release of the Sloan Digital Sky Surveys: Targeting and First Spectra from SDSS-V

The eighteenth data release of the Sloan Digital Sky Surveys (SDSS) is the first one for SDSS-V, the fifth generation of the survey. SDSS-V comprises three primary scientific programs, or "Mappers": Milky Way Mapper (MWM), Black Hole Mapper (BHM), and Local Volume Mapper (LVM). This data release contains extensive targeting information for the two multi-object spectroscopy programs (MWM and BHM), including input catalogs and selection functions for their numerous scientific objectives. We describe the production of the targeting databases and their calibration- and scientifically-focused components. DR18 also includes ~25,000 new SDSS spectra and supplemental information for X-ray sources identified by eROSITA in its eFEDS field. We present updates to some of the SDSS software pipelines and preview changes anticipated for DR19. We also describe three value-added catalogs (VACs) based on SDSS-IV data that have been published since DR17, and one VAC based on the SDSS-V data in the eFEDS field.Comment: Accepted to ApJ