超分子主体による溶媒オーダーリングによる調節可能な電化学エントロピー
Kay T Xia1,2, Aravindh Rajan3, Yogesh Surendranath4
1Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
Journal of the American Chemical Society
|November 13, 2023
まとめ
この研究は,電気化学的なエントロピー生成のための新しいホスト-ゲストシステムを提示し,廃棄熱の収穫のための調整可能で効率的な方法を提供します. このシステムは,現在の技術よりもはるかに大きなエントロピーの変化を達成します.
科学分野:
- 超分子化学
- 電気化学
- 材料科学
背景:
- 熱再生電気化学サイクル (TREC) は,廃棄熱の回収と電気化学的な冷却に不可欠です.
- カリウムフェルシアン化物のような既存の水性TREC電解質は,モラーエントロピーの変化に制限があります.
- レドックスエントロピーの変化を最大化することは,TRECの効率を改善するための鍵です.
研究 の 目的:
- 大規模で調整可能な redox エントロピー変化を持つ水性電気化学的に制御された宿主-ゲストエンカプスレーションシステムを開発する.
- 構造的な溶媒の分子を移動することによってエントロピーを増加させるための新しい戦略を調査する.
- 高エントロピーの電解質の合理的な設計の可能性を実証する.
主な方法:
- 超分子ホスト-ゲストシステムの設計と合成.
- レドックスエントロピーの変化 (ΔS) を測定するための電気化学的特徴付け.
- ホスト・リガンドと金属の頂点を体系的に改変して性能を調整する.
主要な成果:
- ホスト・ゲストシステムは,カリウムフェルシアン化物より約4倍のモラーエントロピーの変化を達成しました.
- エントロピーの増加に大きく貢献した.
- -51から-101cal mol−1 K−1までの広い範囲の ΔS 値が認められる.
結論:
- 高エントロピーの電解質に 新しい可能性が生まれます
- このアプローチは,イオン溶解再構成エントロピーの理論的限界を克服するための戦略を提供します.
- この発見は,より効率的な熱加熱式廃棄熱回収と電気化学的な冷却技術への道を開く.
関連する概念動画
Entropy and Solvation
7.1K
The process of surrounding a solute with solvent is called solvation. It involves evenly distributing the solute within the solvent. The rule of thumb for determining a solvent for a given compound is that like dissolves like. A good solvent has molecular characteristics similar to those of the compound to be dissolved. For example, polar solutions dissolve polar solutes, and apolar solvents dissolve apolar solutes. A polar solvent is a solvent that has a high dielectric constant (ϵ...
7.1K
Enthalpy of Solution
24.9K
There are two criteria that favor, but do not guarantee, the spontaneous formation of a solution:
24.9K
Chemical and Solubility Equilibria
4.1K
The free energy change associated with dissolving a solute in a liter of solvent is called the free energy of a solution, ΔGsolution. The overall ΔGsolution is expressed as the balance of ΔGinteraction against the always-favorable free-energy of mixing, ΔGmixing. Solution formation is favorable if ΔGsolution is less than zero, whereas it is unfavorable if ΔGsolution is greater than zero. In short, for a solution to form and complete dissolution to take place,...
4.1K
Energetics of Solution Formation
6.8K
The formation of a solution is an example of a spontaneous process, which is a process that occurs under specified conditions without energy from some external source.
When the strengths of the intermolecular forces of attraction between solute and solvent species in a solution are no different than those present in the separated components, the solution is formed with no accompanying energy change. Formation of the solution requires the solute–solute and solvent–solvent...
When the strengths of the intermolecular forces of attraction between solute and solvent species in a solution are no different than those present in the separated components, the solution is formed with no accompanying energy change. Formation of the solution requires the solute–solute and solvent–solvent...
6.8K
Complexation Equilibria: The Chelate Effect
524
In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...
524
Entropy
30.3K
Salt particles that have dissolved in water never spontaneously come back together in solution to reform solid particles. Moreover, a gas that has expanded in a vacuum remains dispersed and never spontaneously reassembles. The unidirectional nature of these phenomena is the result of a thermodynamic state function called entropy (S). Entropy is the measure of the extent to which the energy is dispersed throughout a system, or in other words, it is proportional to the degree of disorder of a...
30.3K


