Search NASA⌕ Search

DOE OSTI · 1759387

Materials Data on Th2Fe17C by Materials Project

Abstract

Th2Fe17C crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Th is bonded in a distorted single-bond geometry to fourteen Fe and one C atom. There are a spread of Th–Fe bond distances ranging from 3.05–3.34 Å. The Th–C bond length is 2.62 Å. There are seven inequivalent Fe sites. In the first Fe site, Fe is bonded to three equivalent Th and nine Fe atoms to form distorted FeTh3Fe9 cuboctahedra that share corners with seventeen FeTh3Fe9 cuboctahedra, corners with two equivalent CTh2Fe4 octahedra, edges with seven FeTh3Fe9 cuboctahedra, faces with fourteen FeTh3Fe9 cuboctahedra, and a faceface with one CTh2Fe4 octahedra. The corner-sharing octahedra tilt angles range from 66–70°. There are a spread of Fe–Fe bond distances ranging from 2.48–2.71 Å. In the second Fe site, Fe is bonded in a single-bond geometry to seven Fe and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.48–2.69 Å. The Fe–C bond length is 1.92 Å. In the third Fe site, Fe is bonded to two equivalent Th and ten Fe atoms to form FeTh2Fe10 cuboctahedra that share corners with twelve FeTh3Fe9 cuboctahedra, corners with two equivalent CTh2Fe4 octahedra, edges with eight FeTh2Fe10 cuboctahedra, and faces with twelve FeTh3Fe9 cuboctahedra. The corner-sharing octahedral tilt angles are 44°. There are four shorter (2.43 Å) and two longer (2.66 Å) Fe–Fe bond lengths. In the fourth Fe site, Fe is bonded to two equivalent Th and ten Fe atoms to form distorted FeTh2Fe10 cuboctahedra that share corners with eighteen FeTh3Fe9 cuboctahedra, edges with six FeTh2Fe10 cuboctahedra, faces with fourteen FeTh3Fe9 cuboctahedra, and faces with two equivalent CTh2Fe4 octahedra. There are a spread of Fe–Fe bond distances ranging from 2.43–2.65 Å. In the fifth Fe site, Fe is bonded in a 2-coordinate geometry to one Th and thirteen Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.38–2.73 Å. In the sixth Fe site, Fe is bonded in a single-bond geometry to eight Fe and one C atom. Both Fe–Fe bond lengths are 2.45 Å. The Fe–C bond length is 1.86 Å. In the seventh Fe site, Fe is bonded to two equivalent Th and ten Fe atoms to form distorted FeTh2Fe10 cuboctahedra that share corners with sixteen FeTh3Fe9 cuboctahedra, corners with two equivalent CTh2Fe4 octahedra, edges with four FeTh3Fe9 cuboctahedra, an edgeedge with one CTh2Fe4 octahedra, and faces with fifteen FeTh3Fe9 cuboctahedra. The corner-sharing octahedra tilt angles range from 24–30°. The Fe–Fe bond length is 2.45 Å. C is bonded to two equivalent Th and four Fe atoms to form CTh2Fe4 octahedra that share corners with eighteen FeTh2Fe10 cuboctahedra, edges with four equivalent FeTh2Fe10 cuboctahedra, and faces with eight FeTh2Fe10 cuboctahedra.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-09-03. Materials Data on Th2Fe17C by Materials Project. https://doi.org/10.17188/1759387

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↗