酸化と還元サイクル中のサポートされたRhナノ粒子の形状の変化
P Nolte1, A Stierle, N Y Jin-Phillipp
1Max-Planck-Institut für Metallforschung, Heisenbergstrasse 3, D-70569 Stuttgart, Germany.
まとめ
ロジウムナノ粒子は酸化過程で形状を変え,一酸化炭素によって逆転する. この発見は,触媒反応中のナノ粒子の行動に関する洞察を提供します.
科学分野:
- 異質なカタリシスである.
- マテリアルサイエンス 材料科学
- 表面化学について
背景:
- 触媒反応中のナノ粒子の形状の変化を理解することは,基本的な触媒知識にとって極めて重要です.
- 酸化と還元サイクルは,ナノ粒子構造と反応性に大きな影響を与えます.
研究 の 目的:
- 酸化マグネシウムの基板上のロジウムナノ粒子の酸素誘発の形状変容を調査する.
- この形状の変化とその逆転の背後にあるメカニズムを探求する.
主な方法:
- 高解像度インシットX線 difrractionによる高解像度X線 difrractionによる高解像度X線 difrractionによる高解像度X線 difrractionによる高解像度X線 difrractionによる
- トランスミッション電子顕微鏡
- ウルフ分析とは
主要な成果:
- ロジウムナノ粒子は,酸素の曝露により,酸化マグネシウム (001) の上で形状変化を経験します.
- 600ケルビンで一酸化炭素にさらされると,この形状の変化は逆転する.
- この現象は,ロジウムナノファセットの表面酸化物層 (酸素-ロジウム-酸素) の形成によって引き起こされる.
結論:
- この研究は,触媒サイクル中のナノ粒子ダイナミクスに関する実験的洞察を提供します.
- この理解は,性能を改善した高度な異質な触媒の設計と開発に不可欠です.
関連する概念動画
Oxidation and Reduction of Organic Molecules
Energy production within a cell involves many coordinated chemical pathways. Most of these pathways are combinations of oxidation and reduction reactions, which occur at the same time. An oxidation reaction strips an electron from an atom in a compound, and the addition of this electron to another compound is a reduction reaction. Because oxidation and reduction usually occur together, these pairs of reactions are called redox reactions.
The removal of an electron from a molecule, results in a...
The removal of an electron from a molecule, results in a...
Properties of Transition Metals
Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3–12 are transition elements. The f-block elements, also called inner transition metals (the lanthanides and actinides), also meet this criterion because the d orbital is partially occupied before the f orbitals.
Oxidation-Reduction Reactions
Oxidation–Reduction Reactions
Oxidation of Phenols to Quinones
In the presence of oxidizing agents, phenols are oxidized to quinones. Quinones can be easily reduced back to phenols using mild reducing agents. The electron-donating hydroxyl group enhances the reactivity of the aromatic ring, enabling oxidation of the ring even in the absence of an α hydrogen.
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...
Redox Reactions
Oxidation-reduction or redox reactions involve the transfer of electrons from one molecule or atom to another. When an atom gains an electron, another atom must lose an electron, meaning oxidation and reduction must occur together. Since the redox occurs in pairs, the atom that gets oxidized is also called the reducing agent or reductant, and the atom that is reduced is also called the oxidizing agent or oxidant. A straightforward way to remember the definitions of oxidation and reduction is...
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...


