Engineering Papers⌕ Search

DOE OSTI · 1685777

Materials Data on UHg3 by Materials Project

Abstract

UHg3 is beta-derived structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. U is bonded to six equivalent U and six equivalent Hg atoms to form UU6Hg6 cuboctahedra that share corners with six equivalent UU6Hg6 cuboctahedra, corners with twelve equivalent HgHg12 cuboctahedra, edges with six equivalent UU6Hg6 cuboctahedra, edges with twelve equivalent HgU3Hg9 cuboctahedra, faces with six equivalent UU6Hg6 cuboctahedra, and faces with fourteen HgHg12 cuboctahedra. All U–U bond lengths are 3.18 Å. All U–Hg bond lengths are 3.30 Å. There are two inequivalent Hg sites. In the first Hg site, Hg is bonded to twelve Hg atoms to form HgHg12 cuboctahedra that share corners with six equivalent HgHg12 cuboctahedra, corners with twelve equivalent UU6Hg6 cuboctahedra, edges with eighteen HgHg12 cuboctahedra, faces with two equivalent UU6Hg6 cuboctahedra, and faces with eighteen HgHg12 cuboctahedra. There are six shorter (3.18 Å) and six longer (3.26 Å) Hg–Hg bond lengths. In the second Hg site, Hg is bonded to three equivalent U and nine Hg atoms to form distorted HgU3Hg9 cuboctahedra that share corners with eighteen equivalent HgU3Hg9 cuboctahedra, edges with six equivalent UU6Hg6 cuboctahedra, edges with twelve HgHg12 cuboctahedra, faces with six equivalent UU6Hg6 cuboctahedra, and faces with fourteen HgHg12 cuboctahedra. All Hg–Hg bond lengths are 3.18 Å.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-05-03. Materials Data on UHg3 by Materials Project. https://doi.org/10.17188/1685777

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↗