Engineering Papers⌕ Search

DOE OSTI · 1323768

Materials Data on MgAg2P2O9 by Materials Project

Abstract

MgAg2P2O9 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are four inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with four AgO6 octahedra, corners with two equivalent AgO6 pentagonal pyramids, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–69°. There are a spread of Mg–O bond distances ranging from 2.14–2.38 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with six AgO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–69°. There are a spread of Mg–O bond distances ranging from 2.16–2.37 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with four AgO6 octahedra, corners with two equivalent AgO6 pentagonal pyramids, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–69°. There are a spread of Mg–O bond distances ranging from 2.15–2.38 Å. In the fourth Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with six AgO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–69°. There are a spread of Mg–O bond distances ranging from 2.16–2.37 Å. There are six inequivalent Ag3+ sites. In the first Ag3+ site, Ag3+ is bonded to six O2- atoms to form distorted AgO6 pentagonal pyramids that share corners with two equivalent AgO6 octahedra, corners with four MgO6 octahedra, corners with three PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–63°. There are a spread of Ag–O bond distances ranging from 2.03–2.27 Å. In the second Ag3+ site, Ag3+ is bonded to six O2- atoms to form distorted AgO6 octahedra that share corners with two equivalent AgO6 octahedra, corners with four MgO6 octahedra, corners with three PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–63°. There are a spread of Ag–O bond distances ranging from 2.03–2.27 Å. In the third Ag3+ site, Ag3+ is bonded to six O2- atoms to form distorted AgO6 octahedra that share corners with two equivalent AgO6 octahedra, corners with four MgO6 octahedra, corners with three PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–63°. There are a spread of Ag–O bond distances ranging from 2.04–2.26 Å. In the fourth Ag3+ site, Ag3+ is bonded to six O2- atoms to form distorted AgO6 octahedra that share corners with two equivalent AgO6 octahedra, corners with four MgO6 octahedra, corners with three PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–63°. There are a spread of Ag–O bond distances ranging from 2.04–2.25 Å. In the fifth Ag3+ site, Ag3+ is bonded to six O2- atoms to form distorted AgO6 octahedra that share a cornercorner with one AgO6 octahedra, corners with two MgO6 octahedra, a cornercorner with one AgO6 pentagonal pyramid, corners with four PO4 tetrahedra, and edges with two equivalent AgO6 octahedra. The corner-sharing octahedra tilt angles range from 57–69°. There are a spread of Ag–O bond distances ranging from 2.04–2.66 Å. In the sixth Ag3+ site, Ag3+ is bonded to six O2- atoms to form distorted AgO6 octahedra that share corners with two MgO6 octahedra, corners with two AgO6 octahedra, corners with four PO4 tetrahedra, and edges with two equivalent AgO6 octahedra. The corner-sharing octahedra tilt angles range from 57–69°. There are a spread of Ag–O bond distances ranging from 2.04–2.65 Å. There are eight inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three AgO6 octahedra, corners with two equivalent AgO6 pentagonal pyramids, and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 39–52°. There are a spread of P–O bond distances ranging from 1.51–1.58 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four AgO6 octahedra, a cornercorner with one AgO6 pentagonal pyramid, and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 52–53°. There are a spread of P–O bond distances ranging from 1.52–1.58 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with five AgO6 octahedra and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 39–53°. There are a spread of P–O bond distances ranging from 1.51–1.58 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with five AgO6 octahedra and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 39–53°. There are a spread of P–O bond distances ranging from 1.51–1.58 Å. In the fifth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent AgO6 octahedra, corners with four MgO6 octahedra, and an edgeedge with one AgO6 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 28–59°. There are a spread of P–O bond distances ranging from 1.54–1.61 Å. In the sixth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent AgO6 octahedra, corners with four MgO6 octahedra, and an edgeedge with one AgO6 octahedra. The corner-sharing octahedra tilt angles range from 29–59°. There are a spread of P–O bond distances ranging from 1.54–1.60 Å. In the seventh P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent AgO6 octahedra, corners with four MgO6 octahedra, and an edgeedge with one AgO6 octahedra. The corner-sharing octahedra tilt angles range from 28–59°. There are a spread of P–O bond distances ranging from 1.54–1.60 Å. In the eighth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent AgO6 octahedra, corners with four MgO6 octahedra, and an edgeedge with one AgO6 octahedra. The corner-sharing octahedra tilt angles range from 29–59°. There are a spread of P–O bond distances ranging from 1.54–1.61 Å. There are twenty-eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ag3+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ag3+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ag3+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ag3+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a trigonal planar geometry to three Ag3+ atoms. In the tenth O2- site, O2- is bonded in a trigonal planar geometry to three Ag3+ atoms. In the eleventh O2- site, O2- is bonded in a trigonal planar geometry to three Ag3+ atoms. In the twelfth O2- site, O2- is bonded in a trigonal planar geometry to three Ag3+ atoms. In the thirteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the fifteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the sixteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the seventeenth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the eighteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the nineteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the twentieth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the twenty-first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ag3+ and one P5+ atom. In the twenty-second O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the twenty-third O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the twenty-fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the twenty-fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ag3+ and one P5+ atom. In the twenty-sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ag3+ and one P5+ atom. In the twenty-seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ag3+ and one P5+ atom. In the twenty-eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-08-03. Materials Data on MgAg2P2O9 by Materials Project. https://doi.org/10.17188/1323768

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↗