バイオマス水素化におけるゼオライト結晶による製品選択性
Chengtao Wang1, Liang Wang1, Jian Zhang1
1Key Lab of Applied Chemistry of Zhejiang Province, Department of Chemistry, Zhejiang University , Hangzhou 310028, China.
Journal of the American Chemical Society
|June 17, 2016
まとめ
研究者は,バイオマス水素化のための新しいコアシェル触媒 (Pd@S-1) を開発しました. この金属触媒によるプロセスは,製品の選択性を正確に制御し,フルフラルから98.7%のフラン選択性を達成します.
科学分野:
- カタリシス
- 材料科学
- バイオマス変換
背景:
- 効率的な変換には,金属触媒によるバイオマスの水素化における製品の選択性を制御することが不可欠です.
- ゼオライト結晶は,反応結果に影響を与えるユニークな拡散特性を提供しています.
- 金属ナノ粒子をゼオライトと組み合わせることで 触媒性能を向上させる機会が生まれます
研究 の 目的:
- ゼオライト結晶を用いたバイオマスの水素化における製品の選択性を制御する最初の例を示す.
- パラジウムナノ粒子とシリカリート-Iゼオライトを統合したコアシェル触媒を開発する.
- ゼオライトの微孔が反応経路と製品分布を決定する役割を調査する.
主な方法:
- シリカリット-Iゼオライト結晶の中にパラジウムナノ粒子をカプセル化することによって,コアシェル触媒 (Pd@S-1) の合成.
- Pd@S-1触媒を用いて,金属触媒によるフルフルールの水素化を行う.
- Pd@S-1の触媒性能を,シリカリート-Iゼオライト (Pd/S-1) で浸透された従来のパラジウムナノ粒子と比較する.
主要な成果:
- Pd@S-1コアシェル触媒は,フルフラル水素化で98.7%の例外的に高いフラン選択性を達成した.
- 従来のPd/S-1触媒はフランの選択性 (5.6%) を著しく低下させた.
- 強化された選択性は,ゼオライトの微孔内の水素化製品の制御された質量移転に起因する.
結論:
- シリカライト-Iゼオライト内のパラジウムナノ粒子をカプセル化することで,バイオマス水素化における製品の選択性を効果的に制御するコアシェル構造 (Pd@S-1) が作られます.
- ゼオライトの微孔のユニークな拡散特性は,高いフラン選択性を達成する鍵です.
- このアプローチは,バイオマス由来化合物の選択的触媒変換のための有望な戦略を提供します.
関連する概念動画
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
4.0K
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...
4.0K
02:13Reduction of Alkenes: Catalytic Hydrogenation
14.7K
Alkenes undergo reduction by the addition of molecular hydrogen to give alkanes. Because the process generally occurs in the presence of a transition-metal catalyst, the reaction is called catalytic hydrogenation.
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
14.7K
01:22Heterogeneous Catalysis
75
Heterogeneous catalysis involves a catalyst in a different phase from the reactants. It is a process where the catalyst and the reactants are in distinct phases, typically solid and gas or liquid.Most heterogeneous catalysts are metals, metal oxides, or acids. The list includes transition metals like iron (Fe), cobalt (Co), nickel (Ni), palladium (Pd), platinum (Pt), chromium (Cr), manganese (Mn), tungsten (W), silver (Ag), and copper (Cu). These metals possess partially vacant d orbitals that...
75
02:50Catalysis
31.9K
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
31.9K
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
9.3K
Introduction
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
9.3K
02:17Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule
18.2K
If a set of reactants can yield multiple constitutional isomers, but one of the isomers is obtained as the major product, the reaction is said to be regioselective. In such reactions, bond formation or breaking is favored at one reaction site over others.
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...
18.2K