オレフィンエポキシデーションのためのシリカ基の単一サイトチタン触媒. 触媒構造の制御のための分子前駆体戦略である
Jonggol Jarupatrakorn1, T Don Tilley
1Department of Chemistry, University of California, Berkeley, California 94720-1460, USA.
Journal of the American Chemical Society
|July 11, 2002
まとめ
研究者らは,分子前駆体移植法を用いて,高度に活性で選択的なチタンのサポートされたエポキシダーション触媒を開発した. SBA-15のようなメソポラスシリカサポーターは,サイクロヘクセンエポキシデーションの触媒性能を向上させた.
科学分野:
- マテリアルサイエンス 材料科学
- カタリシス カタリシス カタリシス
- ナノテクノロジー ナノテクノロジー
背景:
- 効率的で選択的な触媒の開発は,化学合成に不可欠です.
- タイタン基の触媒は酸化反応において有望である.
- サポート上の活性種のサイト隔離は,触媒性能を向上させることができます.
研究 の 目的:
- サイト隔離のチタンサポートエポキシダーション触媒を合成するために.
- これらの新しい触媒の構造と触媒特性を調査する.
- 分子前駆物質とシリカサポーターの触媒活動と選択性に対する影響を評価する.
主な方法:
- Tris ((tert-butoxy) シロキシチタン複合体を用いた分子前駆体アプローチを採用しました.
- アモルフなエアロシール,メソポラスなMCM-41,SBA-15のシリカ基板にチタン複合体を挿入した.
- 粉末X線 difraktion,窒素アドソルプション/デソルプション,赤外線,拡散反射紫外線スペクトルスコピーを用いてサポートされたチタンの種を特徴付けました.
主要な成果:
- サイト隔離で,主に四面体で調整されたチタニウム種をシリカ基板で成功裏に生産しました.
- 触媒の活性と選択性は,前駆体内のシロキシドリガンドの減少とともに増加した.
- メソポラスシリカ (MCM-41,SBA-15) は,サポートとして無形シリカを上回った.
- SBA-15でサポートされたTiSi3は,500〜1500hの回転周波数 (TOF) の非常に活性なサイクロヘクセンエポキシデーション触媒を生成しました.
結論:
- 酸素に富んだシロキシド複合体であるチタンは,サポートされたエポキシデーション触媒の効果的な分子前駆体である.
- サイト・アイソレーションとメソポラス・サポーターの選択は,高触媒性能の重要な要因である.
- 開発された触媒は,効率的なサイクロヘクセンエポキシデーションの有意な可能性を示しています.
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