支持的Pt单原子催化剂中的金属支相互作用促进了晶格氧气激活,以在低度下实现对乙的完全氧化
Tian Tang1, ShunZheng Zhao1, YunPeng Liu2
1Department of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Journal of hazardous materials
|September 19, 2024
概括
一个新的单原子催化剂在低温下有效氧化乙. 这种催化剂表现出极好的稳定性,并为氧化挥发性有机污染物的反应机制提供了洞察力.
科学领域:
- 不同质的催化剂.
- 环境化学环境化学
- 材料科学 材料科学 材料科学
背景情况:
- 氧化挥发性有机化合物 (OVOC) 是重要的空气污染物.
- 完全氧化是去除OVOCs的一个关键方法.
- 开发有效的OVOC氧化催化剂仍然是一个挑战.
研究的目的:
- 为了合成和评估单原子催化剂 (Pt SA) 用于乙氧化.
- 阐明催化机制并确定速度决定的步骤.
- 了解单原子在增强催化活性中的作用.
主要方法:
- 准备1.5Pt SA/γ-Al2O3催化剂的方法.
- 对乙氧化的催化性能测试.
- 材料表征 (例如TEM,XPS) 和现场光谱 (DRIFTS).
- 密度函数理论 (DFT) 的计算.
主要成果:
- 1.5Pt SA/γ-Al2O3催化剂在250°C (T100) 达到完全的乙氧化.
- 单个Pt原子的高分散和强大的金属支相互作用增强了氧化还原特性和氧激活.
- DFT的计算显示,氧气空隙形成能量减少,并促进了电子转移.
- 这种反应遵循了Mars-van Krevelen机制,确定了关键中间体.
- 氧气激活和C-C键裂解被确定为决定速率的步骤.
结论:
- 单原子催化剂在完全氧化乙方面非常有效.
- 催化剂的性能归因于增强的氧气吸附/解离和有利的氧化还原特性.
- 这项研究为设计用于OVOC清除的贵金属催化剂提供了有价值的机械见解.
相关概念视频
Catalysis
26.7K
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.
26.7K
Oxidative Cleavage of Alkenes: Ozonolysis
10.0K
In ozonolysis, ozone is used to cleave a carbon–carbon double bond to form aldehydes and ketones, or carboxylic acids, depending on the work-up.
Ozone is a symmetrical bent molecule stabilized by a resonance structure.
Ozone is a symmetrical bent molecule stabilized by a resonance structure.
10.0K
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
9.9K
Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.
9.9K
Radical Oxidation of Allylic and Benzylic Alcohols
1.9K
Activated manganese(IV) oxide can selectively oxidize allylic and benzylic alcohols via a radical intermediate mechanism. Primary allylic alcohols are oxidized to aldehydes, while secondary allylic alcohols yield ketones. The redox reaction of potassium permanganate with an Mn(II) salt such as manganese sulfate (under either alkaline or acidic conditions), followed by thorough drying, yields the oxidizing agent: activated MnO2. While MnO2 is insoluble in the solvents used for the reaction, the...
1.9K
Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids
5.7K
Diols are compounds with two hydroxyl groups. In addition to syn dihydroxylation, diols can also be synthesized through the process of anti dihydroxylation. The process involves treating an alkene with a peroxycarboxylic acid to form an epoxide. Epoxides are highly strained three-membered rings with oxygen and two carbons occupying the corners of an equilateral triangle. This step is followed by ring-opening of the epoxide in the presence of an aqueous acid to give a trans diol.
5.7K
Oxidation of Alkenes: Syn Dihydroxylation with Potassium Permanganate
11.1K
Alkenes can be dihydroxylated using potassium permanganate. The method encompasses the reaction of an alkene with a cold, dilute solution of potassium permanganate under basic conditions to form a cis-diol along with a brown precipitate of manganese dioxide.
11.1K


