リバーシブルなCO結合は,二価金属カチオンが露出している金属-有機構造で調整可能なCO/H2およびCO/N2分離を可能にします
Eric D Bloch1, Matthew R Hudson, Jarad A Mason
1Department of Chemistry, University of California , Berkeley, California 94720, United States.
Journal of the American Chemical Society
|July 8, 2014
まとめ
6つの金属有機フレームワーク (MOF) は,可逆性のある一酸化炭素 (CO) の結合能力が高いことを示しています. これらのMOFは,工業ガスからCO分離のための冷凍蒸留の有望な固体吸着剤の代替品を提供します.
科学分野:
- マテリアルサイエンス 材料科学
- 無機化学 無機化学とは
- 物理化学 物理化学
背景:
- メタル・オーガニック・フレームワーク (MOF) は,調節性特性を有する多孔結晶材料です.
- 一酸化炭素 (CO) は,効率的な分離技術を必要とする重要な産業用ガスです.
研究 の 目的:
- 6つのM2 ((dobdc) メタル・オーガニック・フレームワークのCO結合能力を調査する.
- COと金属の中心間の構造的および電子的相互作用を特徴づけること.
- CO分離アプリケーションにおけるこれらのMOFの可能性を評価する.
主な方法:
- 6つのM2 ((dobdc) MOFs.の合成と構造的特徴付けについて
- COの調整と電子相互作用を研究するための赤外線スペクトロスコーピー.
- M-CO結合距離と角度を決定するX線結晶学.
- 電子構造分析のための密度関数理論 (DFT) 計算.
- CO吸収と吸収熱を定量化するために,ガス吸附イソサーム測定を行います.
- 選択性計算のための理想的吸収溶液理論 (IAST).
主要な成果:
- すべての6つのM2 ((dobdc)) フレームワークは,高容量で可逆的なCO結合を示す.
- 赤外線スペクトロスコピーは,青にシフトしたC-Oの伸縮周波数を示し,非古典的な金属-CO相互作用を示しています.
- 結晶学的データは,シリーズ全体で異なるM-CO距離とM-C-O角度を明らかにしています.
- DFTの計算は,実験的なスペクトロスコピーと構造的傾向とよく相関しています.
- CO吸附能力は,Fe,Co,Niのフレームワークの金属部位ごとに1COに近づきます.
- イソステリック吸附熱はアーヴィング・ウィリアムズ順に成り,Ni > Co > Fe > Mg > Mn > Zn.
結論:
- M2 ((dobdc) フレームワークは,CO分離のための固体吸着剤として大きな可能性を示しています.
- これらのMOFは,CO浄化のためのエネルギー集約的な冷凍蒸留を潜在的に置き換えることができます.
- 金属カチオン (M) の選択は,吸着剤の再生エネルギーとガス純度に影響します.
- この研究では,M = Mn,Fe,Co,Ni.のための最初の結晶学的に特徴づけられたMgとZnカルボニル化合物と高スピンM(II) カルボニル種を提示しています.
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