通过在有机-无机混合材料中的多个活性位点定位来设计异质催化剂
Véronique Dufaud1, Mark E Davis
1Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.
Journal of the American Chemical Society
|August 2, 2003
概括
合成了具有可调节的硫酸组间隔的催化性半孔SBA-15材料. 具有最佳间隔的硫酸基组的材料在双A合成中表现出优越的催化活性,表明了合作作用.
科学领域:
- 材料科学 材料科学 材料科学
- 催化剂是一种催化剂.
- 纳米技术 纳米技术
背景情况:
- 开发高效的异质催化剂对于可持续的化学合成至关重要.
- 半孔二氧化材料为催化应用提供高表面积和可调节的孔状结构.
- 控制活跃站点的空间布局可以显著影响催化性能.
研究的目的:
- 为了合成具有二硫化物或硫酸盐功能的有机氧前体.
- 为了准备具有不同空间排列的硫酸组的中孔性SBA-15材料.
- 研究空间布局对催化活性和选择性的影响.
主要方法:
- 在合成后将有机素前体移植到中孔性SBA-15上.
- 化学衍生以引入硫醇和硫酸的功能.
- 使用NMR,XRD,TGA/DTA,元素分析和酸容量定位进行表征.
- 催化试验用于将和凝结为双A.
主要成果:
- 在没有分解的情况下成功将前体移植到SBA-15上,形成多个氧桥.
- 合成了各种二硫化物,硫醇,烯硫酸和硫酸修饰的SBA-15材料.
- 硫酸材料 (10.SBA) 的催化活性高于单一功能类型的类似物和硫酸材料.
- 有证据表明,近端硫酸组之间存在合作作用.
结论:
- 硫酸组在半孔上的空间排列显著影响了催化性能.
- 在SBA-15上优化硫酸基的间距,增强了双A合成的催化活性.
- 邻近的功能组之间的合作效应可以提高催化效率.
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.
Introduction to Mechanisms of Enzyme Catalysis
For many years, scientists thought that enzyme-substrate binding took place in a simple "lock-and-key" fashion. This model stated that the enzyme and substrate fit together perfectly in one instantaneous step. However, current research supports a more refined view scientists call induced fit. The induced-fit model expands upon the lock-and-key model by describing a more dynamic interaction between enzyme and substrate. As the enzyme and substrate come together, their interaction causes a mild...
Catalysis
Catalysis influences the rate of chemical reactions by providing an alternative reaction pathway with lower activation energy. A catalyst speeds up a reaction, but it is not consumed during the process. The fundamental principle of catalysis is the ability of a catalyst to alter the reaction mechanism, often introducing a more efficient pathway than the uncatalyzed process.In a catalyzed reaction, the catalyst participates directly in the reaction mechanism. It interacts with reactants to form...
Heterogeneous Catalysis
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...


