PtとLaFeO3の間のエピタキシアルと強いサポートの相互作用は,Pt分散を安定させる
Xinyu Mao, Alexandre C Foucher, Tiziano Montini1
1Department of Chemical and Pharmaceutical Sciences, University of Trieste, via L. Giorgieri 1, Trieste 34127, Italy.
Journal of the American Chemical Society
|May 20, 2020
まとめ
触媒における小さなプラチナ (Pt) 結晶体の安定化は極めて重要です. この研究では,マグネシウムアルミニウム酸化物 (MgAl2O4) にランタンフェライト (LaFeO3) フィルムを使用した厳しい処理の後,Ptナノ粒子が安定していることが示されています.
科学分野:
- 材料科学
- カタリシス
- ナノテクノロジー
背景:
- 小型のプラチナ (Pt) の結晶を,厳しい環境下での支持金属触媒で安定させることは,重要な産業課題です.
- ナノ粒子のサイズを維持することは,高温アプリケーションにおける触媒の活性と長寿に不可欠です.
研究 の 目的:
- MgAl2O4で支えられたランタンフェライト (LaFeO3) フィルムに1-2 nmのPt結晶体の安定化を調査する.
- これらのPtナノ粒子の安定性を複数の高温酸化および還元サイクルで評価する.
主な方法:
- MgAl2O4基板に0.5nmのLaFeO3フィルムの原子層沈殿 (ALD) について
- 高温リドックスサイクル (1073 Kでの酸化および還元)
- スキャニング伝送電子顕微鏡 (STEM) とX線吸収スペクトル顕微鏡 (XAS) を用いた特徴化.
主要な成果:
- Pt粒子は,1073 Kの複数のリドックスサイクル後に1〜2 nmの範囲で成功しました.
- STEM分析では,酸化中のLaFeO3サポートに対するPt結晶の方向性を示した.
- XASはPt環境の変化を確認し,強力な金属サポート相互作用を示唆しました.
- 触媒のCO酸化率は,5回の高温リドックスサイクル後に変わらなかった.
結論:
- LaFeO3フィルム上のPtクラスターのエピタキシアル成長は,安定性を高めるのに寄与する.
- PtとLaFeO3の強い金属サポート相互作用は,ナノ粒子の整合性を維持する鍵です.
- 開発された触媒システムは,厳しい条件下で驚くべき安定性と持続的な性能を示しています.
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