Search NASA⌕ Search

DOE OSTI · 1274024

Materials Data on Co7Mo6 by Materials Project

Abstract

Co7Mo6 is Frank-Kasper $\mu$ Phase structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are three inequivalent Mo sites. In the first Mo site, Mo is bonded in a 6-coordinate geometry to nine Mo and six equivalent Co atoms. There are a spread of Mo–Mo bond distances ranging from 2.74–3.03 Å. There are three shorter (2.65 Å) and three longer (2.69 Å) Mo–Co bond lengths. In the second Mo site, Mo is bonded in a 6-coordinate geometry to four Mo and twelve Co atoms. There are one shorter (2.63 Å) and three longer (2.83 Å) Mo–Mo bond lengths. There are a spread of Mo–Co bond distances ranging from 2.70–2.87 Å. In the third Mo site, Mo is bonded in a 8-coordinate geometry to eight Mo and six equivalent Co atoms. The Mo–Mo bond length is 2.54 Å. All Mo–Co bond lengths are 2.59 Å. There are two inequivalent Co sites. In the first Co site, Co is bonded to seven Mo and five Co atoms to form a mixture of corner, edge, and face-sharing CoCo5Mo7 cuboctahedra. There are a spread of Co–Co bond distances ranging from 2.37–2.40 Å. In the second Co site, Co is bonded to six equivalent Mo and six equivalent Co atoms to form CoCo6Mo6 cuboctahedra that share corners with twelve equivalent CoCo5Mo7 cuboctahedra, edges with six equivalent CoCo6Mo6 cuboctahedra, and faces with eighteen equivalent CoCo5Mo7 cuboctahedra.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-07-15. Materials Data on Co7Mo6 by Materials Project. https://doi.org/10.17188/1274024

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↗