線形自由エネルギー関係とCO2の移行状態分析 調整可能な酸性を持つ第2調整球を持つ還元触媒
Kaeden Teindl1, Brian O Patrick1, Eva M Nichols1
1Department of Chemistry, The University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
Journal of the American Chemical Society
|July 27, 2023
まとめ
分子触媒のプロティック群は 陽子のリレーによってCO2の減少を加速する. 外在の酸と共にそれらの酸度が反応速度を決定し,触媒の設計を導きます.
科学分野:
- 電気化学
- カタリシス
- 物理化学
背景:
- 分子触媒は二次調整球 (SCS) のプロティックグループと,二酸化炭素削減における陽子伝達のために外的酸を使用する.
- SCSと外的酸性酸性との相互作用とその触媒動力学への影響は,まだ完全に理解されていません.
研究 の 目的:
- SCSと外部酸の酸度が,電気化学的CO2削減の動力学にどのように影響するかを調査する.
- SCS と 外的酸の両方から プロトン転送の推進力のメカニズム的貢献を解明する.
主な方法:
- 調節可能なSCSアミドpKa値を持つ鉄テトラフェニルポルフィリン電気触媒の合成
- 異なった酸性を持つフェノルを外部酸として利用した.
- 線形自由エネルギー関係とアイリング解析を用いて反応運動を研究した.
主要な成果:
- 触媒運動は,より酸性のある外来酸で,SCSの酸性に対する感受性の増加を示した (Brønsted α: 0. 82 0. 13).
- また,SCS酸度が増加した外因的酸性に対する感受性も高まった (Brønsted α: 0.620.32).
- Eyringの分析は,電荷と溶解の調節を示唆する,SCS酸度が低下したより秩序ある移行状態を示した.
結論:
- SCSの酸性は,速度制限の移行状態での電荷蓄積と溶解を調節する上で重要な役割を果たします.
- 活性化バリアの最適化には,SCSと外源酸の両方のpKaを考慮する必要があります.
- 発見は,すべての陽子リレーの参加者を考慮することによって,電触媒システムの合理的な設計を導く.
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