活动部位的跟踪以及复合效应对具有优越的催化活性的基于Cu/Ce的催化剂
Jin Zhang1,2, Hongyu Lin1, Xiaoqin Zhang1
1Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China.
JACS Au
|February 28, 2025
概括
将添加到铜催化剂中,通过创造更多不对称的氧空位 (ASOv),增强去除CO和VOC的活性和稳定性,从而增强低温氧化.
科学领域:
- 不同质的催化剂.
- 材料科学是一种材料科学.
- 环境化学环境化学
背景情况:
- 将贵金属催化剂替换为低温CO和VOC氧化的基本金属具有挑战性.
- 基于铜 (Cu/Ce) 的催化剂显示出希望,但它们的活性部位需要进一步研究.
- 了解活性位点对于设计高效和稳定的催化剂至关重要.
研究的目的:
- 探索CuCe催化剂的主要活性位点和合成效应.
- 调查 (Co) 添加在增强催化性能中的作用.
- 阐明CuCoCe催化剂活动和稳定性的改善背后的机制.
主要方法:
- 合成CuCe和CuCoCe催化剂.
- 采用了现场增强的拉曼光谱和现场超低温DRIFTS技术.
- 在反应过程中相对量化和动态跟踪不对称的氧空缺 (ASOv).
主要成果:
- 在CuCe和CuCoCe催化剂中确定的主要活性位点是Cu-OV-Ce接口,称为不对称的氧空位 (ASOv).
- 添加显著降低了ASOv的形成能量 (从1.502到0.854 eV),增加了其度,并促进了CuO和CeO的分散.
- 该Cu1Co0.5Ce3催化剂在96°C和227°C时实现了100%的CO和二氧化碳的转化,显示出卓越的活性和稳定性.
结论:
- 铜-接口上的不对称氧空位 (ASOv) 是CO和VOC氧化的主要活性位点.
- 在CuCe催化剂中加入可以增强ASOv的形成和度,从而提高催化活性和稳定性.
- ASOv的动态氧化还原平衡确保了基于Cu/Ce的系统的长期催化稳定性.
相关概念视频
02:50Catalysis
26.5K
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.
26.5K
01:07Catalytically Perfect Enzymes
3.8K
The theory of catalytically perfect enzymes was first proposed by W.J. Albery and J. R. Knowles in 1976. These enzymes catalyze biochemical reactions at high-speed. Their catalytic efficiency values range from 108-109 M-1s-1. These enzymes are also called 'diffusion-controlled' as the only rate-limiting step in the catalysis is that of the substrate diffusion into the active site. Examples include triose phosphate isomerase, fumarase, and superoxide dismutase.
Most enzymes...
Most enzymes...
3.8K
02:34Enzymes
80.4K
Inside living organisms, enzymes act as catalysts for many biochemical reactions involved in cellular metabolism. The role of enzymes is to reduce the activation energies of biochemical reactions by forming complexes with its substrates. The lowering of activation energies favor an increase in the rates of biochemical reactions.
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
80.4K
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
3.2K
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...
3.2K