在极其基本的条件下通过使用Ru纳米粒子和2-phenyl-4-(1-naphthyl) quinolinium离子进行光催化进化
Yusuke Yamada1, Takamitsu Miyahigashi, Hiroaki Kotani
1Department of Material and Life Science, Graduate School of Engineering, Osaka University, and ALCA, Japan Science and Technology Agency, Suita, Osaka 565-0871, Japan.
Journal of the American Chemical Society
|August 31, 2011
概括
这项研究证明了光催化在基本条件下的演变,使用一种新催化剂系统. 这种新方法实现了与催化剂相当的高效率,为可持续的生产铺平了道路.
科学领域:
- 光催化作用的光催化
- 绿色化学 绿色化学
- 材料科学 材料科学 材料科学
背景情况:
- 的进化是清洁能源生产的关键过程.
- 纳米粒子 (RuNPs) 是有效的进化催化剂.
- 在基本条件下实现高效的进化仍然具有挑战性.
研究的目的:
- 在基本条件下 (pH10) 开发一种新光催化系统,用于的进化.
- 调查所涉及的光动力学和电子转移机制.
- 评估纳米颗粒 (RuNPs) 的催化性能及其尺寸依赖活性.
主要方法:
- 作为光催化剂使用了2--4-(1-纳) 离子 (QuPh(+) -NA) 和作为电子捐赠体使用了二尼胺氨酸二核化物 (NADH).
- 采用纳秒激光闪光光电解来研究反应中间体和动力学.
- 测试了大小控制的RuNP作为进化催化剂.
主要成果:
- 在基本条件下首次通过QuPh(+) -NA/NADH/RuNPs系统实现光催化演化.
- RuNPs的催化活性与商业纳米粒子 (PtNPs) 相当.
- 确定了关键中间体,包括QuPh(+) -NA基离子及其π-二极体,从QuPh(•) -NA转移电子到RuNPs,推动的进化.
- 4.1nm的RuNP显示出每单位重量的最高演变率.
结论:
- 在基本条件下,QuPh(+) -NA/NADH/RuNPs系统可以实现高效的光催化演化.
- 电子转移途径涉及光激发,基离子形成,以及随后的电子转移到RuNP.
- 纳米粒子,特别是大小为4.1纳米,在这个系统中对进化催化非常有效.
相关概念视频
Catalysis
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.
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...
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...
Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride
Radical substitution reactions can be used to remove functional groups from molecules. The hydrogenolysis of alkyl halides is one such reaction, where the weak Sn–H bond in tributyltin hydride reacts with alkyl halides to form alkanes. Here, the reagent Bu3SnH yields tributyltin halide as a byproduct.
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation reactions,...
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation reactions,...


