There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

A comprehensive review on PEM water electrolysis

Hydrogen technologies have experienced cycles of excessive expectations followed by disillusion. Nonetheless, a growing body of evidence suggests these technologies form an attractive option for the deep decarbonisation of global energy systems, and that recent improvements in their cost and performance point towards economic viability as well. This paper is a comprehensive review of the potential role that hydrogen could play in the provision of electricity, heat, industry, transport and energy storage in a low-carbon energy system, and an assessment of the status of hydrogen in being able to fulfil that potential. The picture that emerges is one of qualified promise: hydrogen is well established in certain niches such as forklift trucks, while mainstream applications are now forthcoming. Hydrogen vehicles are available commercially in several countries, and 225 000 fuel cell home heating systems have been sold. This represents a step change from the situation of only five years ago. This review shows that challenges around cost and performance remain, and considerable improvements are still required for hydrogen to become truly competitive. But such competitiveness in the medium-term future no longer seems an unrealistic prospect, which fully justifies the growing interest and policy support for these technologies around the world.

https://pubs.rsc.org/en/content/articlepdf/2019/ee/c8ee01157e

The role of hydrogen and fuel cells in the global energy system

https://publikationen.bibliothek.kit.edu/1000050288/18451059

Renewable Power-to-Gas: A technological and economic review

A positive temperature coefficient is the term which has been used to indicate that an increase in solubility occurs as the temperature is raised, whereas a negative coefficient indicates a decrease in solubility with rise in temperature.

Effect of Temperature

https://digital.csic.es/bitstream/10261/53764/4/Recent%20advances%20in%20high%20temperature.pdf

Recent advances in high temperature electrolysis using solid oxide fuel cells: A review

http://digital.csic.es/bitstream/10261/52660/4/Electrolyte%20Degradation%20in%20Anode.pdf

Electrolyte degradation in anode supported microtubular yttria stabilized zirconia-based solid oxide steam electrolysis cells at high voltages of operation

https://spiral.imperial.ac.uk/bitstream/10044/1/13889/2/Journal%20of%20Power%20Sources_192_1_2009.pdf

Performance of solid oxide electrolysis cells based on scandia stabilised zirconia

The Raman spectrum of NiAl2O4 inverse spinel has been studied in quenched polycrystalline pellets produced by solid-state reaction and in single crystals grown by the floating zone method. The lattice parameters and inversion degrees were determined by x-ray diffraction. Polarization measurements in single crystals allow mode symmetry assignment. Then, a correlation is established between the bands observed in polycrystalline samples and those of single crystals. Both kinds of sample present more bands than the five expected (A1g+Eg+3T2g) in a cubic Fd3m spinel. This multiplicity is attributed to the almost fully inverted cation distribution in NiAl2O4, with inversion parameter x≈0.9. The multiplicity of the high-frequency A1g band, in particular, is attributed to the different possible configurations of Ni2+ and Al3+ cations occupying the three octahedral sites close to a given oxygen ion. A strong downshift of the Eg mode frequency, as compared to the normal spinel MgAl2O4, is attributed to the longer bonding distance between oxygen and octahedral cations in inverse II–III spinels. Due to the small range of variation of x upon thermal treatment in NiAl2O4, no significant differences were found between the spectra of samples quenched at different temperatures, from 800 to 1200 °C.

http://iopscience.iop.org/article/10.1088/0953-8984/19/18/186217/pdf

Raman spectroscopic study of cation disorder in poly- and single crystals of the nickel aluminate spinel.

Two alternative oxygen electrodes (anodes), La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) and La0.8Sr0.2MnO3−δ (lanthanum strontium manganite)/YSZ (yttria stabilized zirconia), were tested in 10Sc1CeSZ (scandia ...

Miguel A. Laguna-Bercero

Papers

Recent advances in high temperature electrolysis using solid oxide fuel cells: A review

Electrolyte degradation in anode supported microtubular yttria stabilized zirconia-based solid oxide steam electrolysis cells at high voltages of operation

Performance of solid oxide electrolysis cells based on scandia stabilised zirconia

Raman spectroscopic study of cation disorder in poly- and single crystals of the nickel aluminate spinel.

Performance and Characterization of (La, Sr)MnO3/YSZ and La0.6Sr0.4Co0.2Fe0.8O3 Electrodes for Solid Oxide Electrolysis Cells†