水素における優先的なCO酸化:コア・シェルナノ粒子の反応性
Anand Udaykumar Nilekar1, Selim Alayoglu, Bryan Eichhorn
1Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
Journal of the American Chemical Society
|May 13, 2010
まとめ
私たちは,水素における優先的なCO酸化 (PROX) のための活性が向上した新しいコアシェルナノ粒子 (NP) 触媒を設計しました. Ru@PtのコアシェルのNPは,低温で効率的なCO酸化を示し,最高性能を示しました.
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:
- 燃料電池のアプリケーションでは,水素における優先的なCO酸化 (PROX) のための効率的な触媒の開発が不可欠です.
- コアシェルのナノ粒子は,インターフェイス効果を制御することによって,調節可能な触媒特性を提供します.
研究 の 目的:
- 新しいM@Ptコアシェルナノ粒子 (NP) 触媒を設計,合成,特徴づけること.
- PROX反応のための彼らの触媒性能を調査するために.
- 密度関数理論 (DFT) を用いて,それらの反応性を支配する基本的メカニズムを解明する.
主な方法:
- 最初の原則は,M@PtのコアシェルのNP (M = Ru, Rh, Ir, Pd, Au) の設計と合成を導いた.
- X線 difraktion,FTIR,HRTEM,および温度プログラム反応を用いた特徴付け.
- PROX.の触媒活性と選択性の評価
- DFT計算を用いたメカニズム研究.
主要な成果:
- 合成されたM@PtコアシェルNPと制御されたPtシェル厚さ (~1-2単層).
- モノメタリックナノ合金とバイメタリックナノ合金と比較して,いくつかのM@PtNPのPROX活性と選択性の有意な改善が観察されました.
- Ru@PtのコアシェルのNPは,最も高い活性を示し,30°Cで完全なCO酸化を達成しました.
- DFTの研究は,O2活性化のための利用可能なCOフリーPtサイトと,水素媒介のCO酸化経路によって活性化が強化されたことを明らかにした.
結論:
- M@PtのコアシェルのNPは,プラチナ含有量が減少した,高度に活性で選択的なPROX触媒の設計に有望な戦略を表しています.
- コアメタルは,Ptシェルの触媒性能に大きな影響を与えます.
- 反応メカニズムの理解は,将来の触媒開発のための洞察を提供します.
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