Search NASA⌕ Search

DOE OSTI · 1758296

Materials Data on Er6Al43Mo4 by Materials Project

Abstract

Er6Mo4Al43 crystallizes in the hexagonal P6_3/mcm space group. The structure is three-dimensional. Er is bonded in a 6-coordinate geometry to one Er, one Mo, and fifteen Al atoms. The Er–Er bond length is 3.43 Å. The Er–Mo bond length is 3.50 Å. There are a spread of Er–Al bond distances ranging from 3.06–3.43 Å. There are two inequivalent Mo sites. In the first Mo site, Mo is bonded in a 10-coordinate geometry to two equivalent Er and ten Al atoms. There are a spread of Mo–Al bond distances ranging from 2.59–2.73 Å. In the second Mo site, Mo is bonded in a cuboctahedral geometry to twelve Al atoms. There are six shorter (2.68 Å) and six longer (2.86 Å) Mo–Al bond lengths. There are seven inequivalent Al sites. In the first Al site, Al is bonded in a 2-coordinate geometry to one Er, two Mo, and five Al atoms. There are a spread of Al–Al bond distances ranging from 2.74–2.87 Å. In the second Al site, Al is bonded in a 12-coordinate geometry to four equivalent Er and eight Al atoms. There are a spread of Al–Al bond distances ranging from 2.74–3.06 Å. In the third Al site, Al is bonded in a 1-coordinate geometry to two equivalent Er, one Mo, and nine Al atoms. There are a spread of Al–Al bond distances ranging from 2.72–3.05 Å. In the fourth Al site, Al is bonded in a distorted linear geometry to two equivalent Mo and four equivalent Al atoms. In the fifth Al site, Al is bonded in a 12-coordinate geometry to two equivalent Er, one Mo, and nine Al atoms. Both Al–Al bond lengths are 3.01 Å. In the sixth Al site, Al is bonded to three equivalent Er and nine Al atoms to form a mixture of corner and face-sharing AlEr3Al9 cuboctahedra. All Al–Al bond lengths are 2.83 Å. In the seventh Al site, Al is bonded in a 1-coordinate geometry to two equivalent Er, one Mo, and six Al atoms.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-09-03. Materials Data on Er6Al43Mo4 by Materials Project. https://doi.org/10.17188/1758296

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↗