Search NASA⌕ Search

DOE OSTI · 1679248

Materials Data on ZrNb(SiRu)2 by Materials Project

Abstract

ZrNb(RuSi)2 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are three inequivalent Zr2+ sites. In the first Zr2+ site, Zr2+ is bonded to five Si4- atoms to form ZrSi5 square pyramids that share corners with five ZrSi5 square pyramids, corners with five NbSi5 square pyramids, corners with six RuSi4 tetrahedra, edges with two NbSi5 square pyramids, edges with four ZrSi5 square pyramids, and edges with six RuSi4 tetrahedra. There are four shorter (2.74 Å) and one longer (2.77 Å) Zr–Si bond lengths. In the second Zr2+ site, Zr2+ is bonded to five Si4- atoms to form ZrSi5 square pyramids that share a cornercorner with one ZrSi5 square pyramid, corners with nine NbSi5 square pyramids, corners with six RuSi4 tetrahedra, edges with two equivalent ZrSi5 square pyramids, edges with four NbSi5 square pyramids, and edges with six RuSi4 tetrahedra. There are three shorter (2.75 Å) and two longer (2.77 Å) Zr–Si bond lengths. In the third Zr2+ site, Zr2+ is bonded to five Si4- atoms to form ZrSi5 square pyramids that share corners with four equivalent ZrSi5 square pyramids, corners with six NbSi5 square pyramids, corners with six RuSi4 tetrahedra, edges with two NbSi5 square pyramids, edges with four ZrSi5 square pyramids, and edges with six RuSi4 tetrahedra. There are a spread of Zr–Si bond distances ranging from 2.74–2.77 Å. There are three inequivalent Nb2+ sites. In the first Nb2+ site, Nb2+ is bonded to five Si4- atoms to form distorted NbSi5 square pyramids that share corners with three equivalent NbSi5 square pyramids, corners with seven ZrSi5 square pyramids, corners with six RuSi4 tetrahedra, edges with three ZrSi5 square pyramids, edges with three NbSi5 square pyramids, and edges with six RuSi4 tetrahedra. There are a spread of Nb–Si bond distances ranging from 2.68–2.76 Å. In the second Nb2+ site, Nb2+ is bonded to five Si4- atoms to form NbSi5 square pyramids that share corners with two equivalent NbSi5 square pyramids, corners with eight ZrSi5 square pyramids, corners with six RuSi4 tetrahedra, edges with three ZrSi5 square pyramids, edges with three NbSi5 square pyramids, and edges with six RuSi4 tetrahedra. There are a spread of Nb–Si bond distances ranging from 2.69–2.72 Å. In the third Nb2+ site, Nb2+ is bonded to five Si4- atoms to form NbSi5 square pyramids that share corners with five ZrSi5 square pyramids, corners with five NbSi5 square pyramids, corners with six RuSi4 tetrahedra, edges with two equivalent ZrSi5 square pyramids, edges with four NbSi5 square pyramids, and edges with six RuSi4 tetrahedra. There are two shorter (2.70 Å) and three longer (2.72 Å) Nb–Si bond lengths. There are six inequivalent Ru2+ sites. In the first Ru2+ site, Ru2+ is bonded to four Si4- atoms to form RuSi4 tetrahedra that share corners with two equivalent NbSi5 square pyramids, corners with four ZrSi5 square pyramids, corners with ten RuSi4 tetrahedra, edges with two equivalent ZrSi5 square pyramids, edges with four NbSi5 square pyramids, and edges with two RuSi4 tetrahedra. There are a spread of Ru–Si bond distances ranging from 2.48–2.51 Å. In the second Ru2+ site, Ru2+ is bonded to four Si4- atoms to form RuSi4 tetrahedra that share corners with two equivalent ZrSi5 square pyramids, corners with four NbSi5 square pyramids, corners with ten RuSi4 tetrahedra, edges with two equivalent NbSi5 square pyramids, edges with four ZrSi5 square pyramids, and edges with two RuSi4 tetrahedra. There are a spread of Ru–Si bond distances ranging from 2.51–2.54 Å. In the third Ru2+ site, Ru2+ is bonded to four Si4- atoms to form RuSi4 tetrahedra that share corners with two equivalent NbSi5 square pyramids, corners with four ZrSi5 square pyramids, corners with ten RuSi4 tetrahedra, edges with two equivalent ZrSi5 square pyramids, edges with four NbSi5 square pyramids, and edges with two RuSi4 tetrahedra. There are a spread of Ru–Si bond distances ranging from 2.46–2.52 Å. In the fourth Ru2+ site, Ru2+ is bonded to four Si4- atoms to form RuSi4 tetrahedra that share corners with two equivalent ZrSi5 square pyramids, corners with four NbSi5 square pyramids, corners with ten RuSi4 tetrahedra, edges with two equivalent NbSi5 square pyramids, edges with four ZrSi5 square pyramids, and edges with two RuSi4 tetrahedra. There are a spread of Ru–Si bond distances ranging from 2.48–2.57 Å. In the fifth Ru2+ site, Ru2+ is bonded to four Si4- atoms to form RuSi4 tetrahedra that share corners with two equivalent ZrSi5 square pyramids, corners with four NbSi5 square pyramids, corners with ten RuSi4 tetrahedra, edges with two equivalent ZrSi5 square pyramids, edges with four NbSi5 square pyramids, and edges with two RuSi4 tetrahedra. There are a spread of Ru–Si bond distances ranging from 2.44–2.57 Å. In the sixth Ru2+ site, Ru2+ is bonded to four Si4- atoms to form RuSi4 tetrahedra that share corners with two equivalent NbSi5 square pyramids, corners with four ZrSi5 square pyramids, corners with ten RuSi4 tetrahedra, edges with two equivalent NbSi5 square pyramids, edges with four ZrSi5 square pyramids, and edges with two RuSi4 tetrahedra. There are a spread of Ru–Si bond distances ranging from 2.45–2.58 Å. There are six inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a 9-coordinate geometry to two equivalent Zr2+, four Nb2+, and three Ru2+ atoms. In the second Si4- site, Si4- is bonded in a 9-coordinate geometry to four Zr2+, two equivalent Nb2+, and three Ru2+ atoms. In the third Si4- site, Si4- is bonded in a 9-coordinate geometry to two equivalent Zr2+, four Nb2+, and three Ru2+ atoms. In the fourth Si4- site, Si4- is bonded in a 9-coordinate geometry to four Zr2+, two equivalent Nb2+, and three Ru2+ atoms. In the fifth Si4- site, Si4- is bonded in a 9-coordinate geometry to one Zr2+, two Nb2+, and six Ru2+ atoms. In the sixth Si4- site, Si4- is bonded in a 9-coordinate geometry to two Zr2+, one Nb2+, and six Ru2+ atoms.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-05-03. Materials Data on ZrNb(SiRu)2 by Materials Project. https://doi.org/10.17188/1679248

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↗