Search NASA⌕ Search

DOE OSTI · 1206913

Materials Data on Al2FeO4 by Materials Project

Abstract

FeAl2O4 is Spinel-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are six inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with three equivalent FeO6 octahedra and corners with nine AlO6 octahedra. The corner-sharing octahedra tilt angles range from 55–67°. There are a spread of Fe–O bond distances ranging from 1.97–2.03 Å. In the second Fe2+ site, Fe2+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three equivalent FeO4 tetrahedra, corners with three equivalent AlO4 tetrahedra, and edges with six AlO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.06–2.18 Å. In the third Fe2+ site, Fe2+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with twelve AlO6 octahedra. The corner-sharing octahedra tilt angles range from 57–61°. There is one shorter (1.98 Å) and three longer (2.01 Å) Fe–O bond length. In the fourth Fe2+ site, Fe2+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with twelve AlO6 octahedra. The corner-sharing octahedra tilt angles range from 59–61°. There are one shorter (2.00 Å) and three longer (2.01 Å) Fe–O bond lengths. In the fifth Fe2+ site, Fe2+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with twelve AlO6 octahedra. The corner-sharing octahedra tilt angles range from 58–63°. There are a spread of Fe–O bond distances ranging from 2.01–2.06 Å. In the sixth Fe2+ site, Fe2+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with twelve AlO6 octahedra. The corner-sharing octahedra tilt angles range from 59–63°. There are a spread of Fe–O bond distances ranging from 2.00–2.07 Å. There are twelve inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with five FeO4 tetrahedra, an edgeedge with one FeO6 octahedra, and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.89–2.08 Å. In the second Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six FeO4 tetrahedra and edges with six AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.93–1.95 Å. In the third Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with five FeO4 tetrahedra, an edgeedge with one FeO6 octahedra, and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–2.11 Å. In the fourth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six FeO4 tetrahedra and edges with six AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.92–1.95 Å. In the fifth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with five FeO4 tetrahedra, an edgeedge with one FeO6 octahedra, and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–2.09 Å. In the sixth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six FeO4 tetrahedra and edges with six AlO6 octahedra. There is two shorter (1.93 Å) and four longer (1.95 Å) Al–O bond length. In the seventh Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two equivalent AlO4 tetrahedra, corners with four FeO4 tetrahedra, an edgeedge with one FeO6 octahedra, and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.92–2.01 Å. In the eighth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six FeO4 tetrahedra and edges with six AlO6 octahedra. There is five shorter (1.93 Å) and one longer (1.94 Å) Al–O bond length. In the ninth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six FeO4 tetrahedra and edges with six AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.93–1.95 Å. In the tenth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two equivalent AlO4 tetrahedra, corners with four FeO4 tetrahedra, an edgeedge with one FeO6 octahedra, and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.91–2.01 Å. In the eleventh Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two equivalent AlO4 tetrahedra, corners with four FeO4 tetrahedra, an edgeedge with one FeO6 octahedra, and edges with five AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.92–1.99 Å. In the twelfth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with three equivalent FeO6 octahedra and corners with nine AlO6 octahedra. The corner-sharing octahedra tilt angles range from 54–63°. There is two shorter (1.83 Å) and two longer (1.84 Å) Al–O bond length. There are twenty-four inequivalent O2- sites. In the first O2- site, O2- is bonded to two Fe2+ and two Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl2Fe2 trigonal pyramids. In the second O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form distorted OAl3Fe trigonal pyramids that share corners with nine OAl3Fe tetrahedra and edges with two OAl2Fe2 trigonal pyramids. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Fe2+ and two Al3+ atoms. In the fourth O2- site, O2- is bonded to two Fe2+ and two Al3+ atoms to form distorted OAl2Fe2 trigonal pyramids that share corners with four OAl3Fe tetrahedra, corners with two OAl3Fe trigonal pyramids, and edges with two OAl2Fe2 trigonal pyramids. In the fifth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl3Fe tetrahedra. In the sixth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form distorted OAl3Fe tetrahedra that share corners with six OAl3Fe tetrahedra, corners with five OAl2Fe2 trigonal pyramids, and edges with two OAl3Fe tetrahedra. In the seventh O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form distorted OAl3Fe tetrahedra that share corners with six OAl3Fe tetrahedra, corners with four OAl2Fe2 trigonal pyramids, and edges with two OAl3Fe tetrahedra. In the eighth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl3Fe trigonal pyramids. In the ninth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl3Fe tetrahedra. In the tenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Al3+ atoms. In the eleventh O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl3Fe tetrahedra. In the twelfth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form distorted OAl3Fe tetrahedra that share corners with six OAl3Fe tetrahedra, corners with five OAl2Fe2 trigonal pyramids, and edges with two OAl3Fe tetrahedra. In the thirteenth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl3Fe tetrahedra. In the fourteenth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl3Fe tetrahedra. In the fifteenth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl3Fe tetrahedra. In the sixteenth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form distorted OAl3Fe trigonal pyramids that share corners with three equivalent OAl3Fe tetrahedra, corners with two OAl2Fe2 trigonal pyramids, and edges with three OAl3Fe tetrahedra. In the seventeenth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl3Fe tetrahedra. In the eighteenth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl3Fe tetrahedra. In the nineteenth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl3Fe tetrahedra. In the twentieth O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form a mixture of distorted edge and corner-sharing OAl3Fe tetrahedra. In the twenty-first O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Fe2+ and three Al3+ atoms. In the twenty-second O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Fe2+ and three Al3+ atoms. In the twenty-third O2- site, O2- is bonded to one Fe2+ and three Al3+ atoms to form corner-sharing OAl3Fe tetrahedra. In the twenty-fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Fe2+ and three Al3+ atoms.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-07-14. Materials Data on Al2FeO4 by Materials Project. https://doi.org/10.17188/1206913

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related reports

Cyclic moisture reactivation of calcium sorbents for long duration thermochemical energy storage

The transition to a flexible and reliable energy infrastructure, using electro-thermal energy generation technologies such as geothermal, concentrated solar power, and nuclear, usually demands simultaneous advancement of thermal energy storage (TES) to support on-demand electricity generation and industrial applications while mitigating the inherent intermittency of renewable energy sources and power outages from direct energy generation. Among TES technologies, thermochemical energy storage (TCES) based on calcium looping emerges as a compelling high-power energy storage candidate due to its high reaction enthalpy, compatibility with elevated operating temperatures, and abundance of low-cost materials. However, the long-term durability of calcium-based sorbents for TCES is hindered by surface sintering and particle aggregation, leading to performance degradation over repeated thermal cycles. This study explores a moisture hydration-based strategy to regenerate a degraded calcium sorbent and mitigate performance degradation for long duration TCES. The addition of moisture transforms calcium oxide into calcium hydroxide and produces intercalation water layers, associated with a regenerated surface area and reduced calcium oxide crystallite size. Both these effects are beneficial in restoring the sorbents' reactivity for carbonization. Additionally, an optimized hydration-assisted reactivation protocol balances the recovered energy storage capacity with heating penalty required for moisture removal from hydrated samples, resulting in an enhanced energy storage capacity up to 176% compared to benchmark sorbents that undergo cycling without reactivation after 60 cycles. In conclusion, these results highlight the potential of hydration-assisted reactivation to enhance the long-term performance of TCES, providing an effective pathway to advancing electro-thermal storage technologies.

36 MATERIALS SCIENCE↗