Understanding the Mechanism of Plasma-assisted Catalysis: Visit by Prof. Y.S. Mok

了解等离子体辅助催化机制：Y.S.教授来访

• 批准号: EP/E032656/1
• 负责人: John Whitehead
• 金额: $ 1.39万
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FE032656%2F1
• 关键词: Understanding; Mechanism; Plasma; assisted; Catalysis

This proposal seeks support to enable Professor YS Mok from Cheju University in Korea to spend his sabbatical year in a collaborative investigation with the Plasma Chemistry group in the School of Chemistry at The University of Manchester. Professor Mok is an experienced researcher working in the field of plasma-assisted catalysis for environmental clean-up, particularly the removal of NOx from diesel exhaust. The purpose of the proposed investigation is to study the mechanism by which combining a plasma discharge with a catalyst increases the efficiency of both processes for the destruction of pollutants such as VOCs and NOx in waste gas streams. The plasma discharge in the waste gas creates highly energetic electrons which go on to create excited atoms, molecules and radicals. These species then initiate a series of chemical reactions that destroy the pollutants, ideally converting them into benign compounds which can be safely vented to atmosphere or into compounds that can be removed and possibly recycled. It is found that the combination of plasma and catalysis increase the destruction efficiency of the catalyst reducing its operating temperature in some cases close to ambient. This can bring about a factor of ten reduction in the energy consumption compared to the operation of the catalyst alone. However, the mechanism of the processes by which the plasma discharge activates the catalyst is not clearly understood. It might involve interaction of plasma-generated electrons and photons with the catalyst surface or radicals are produced which are adsorbed onto the catalyst and open up new reaction pathways. Alternatively, the plasma may simply change the nature of the gas by chemical reaction before interaction with the catalyst. We will conduct a series of experiments with a range of catalytic materials and different plasma discharge configurations using on-line chemical analysis of the exiting gas stream to understand the chemistry of the process and to determine the key parameters involved. Studies of the temperature dependence of the plasma-activated catalysis will yield kinetic information including activation energies. A range of analytical and surface characterisation techniques will be used to study any changes in the catalysts following processing which will yield information on the surface species involved. A computer-based model that incorporates the gas-phase and heterogeneous chemistry together with the electrical properties of the plasma and the gas dynamics will be developed. It is hoped that this model will identify the key processes involved in plasma-assisted catalysis allowing us to develop fundamental molecular mechanisms via the modelling that can be used both in an interpretative and predictive mode.

该提案寻求支持，使韩国济州大学的YS Mok教授能够在他的休假年与曼彻斯特大学化学学院的等离子体化学小组进行合作研究。莫教授是一名经验丰富的研究人员，致力于等离子体辅助催化净化环境，特别是去除柴油废气中的氮氧化物。本研究的目的是研究等离子体放电与催化剂相结合的机制，以提高两种工艺对废气流中voc和NOx等污染物的破坏效率。废气中的等离子体放电产生高能量的电子，这些电子继续产生受激的原子、分子和自由基。然后，这些物种启动一系列化学反应，破坏污染物，理想情况下，将污染物转化为无害的化合物，可以安全地排放到大气中，或者转化为可以去除并可能回收的化合物。研究发现，等离子体与催化剂的结合提高了催化剂的破坏效率，在某些情况下使催化剂的工作温度降低到接近环境温度。与单独使用催化剂相比，这可以使能耗降低十倍。然而，等离子体放电激活催化剂的过程机制尚不清楚。它可能涉及等离子体产生的电子和光子与催化剂表面的相互作用或产生自由基，这些自由基被吸附在催化剂上，开辟了新的反应途径。或者，在与催化剂相互作用之前，等离子体可以简单地通过化学反应改变气体的性质。我们将使用一系列催化材料和不同的等离子体放电配置进行一系列实验，使用在线化学分析出气流，以了解该过程的化学性质并确定所涉及的关键参数。对等离子体活化催化的温度依赖性的研究将得到包括活化能在内的动力学信息。一系列的分析和表面表征技术将用于研究催化剂在加工后的任何变化，这将产生有关表面物质的信息。将开发一个结合气相和非均相化学以及等离子体电学性质和气体动力学的计算机模型。希望该模型将确定等离子体辅助催化的关键过程，使我们能够通过建模开发基本的分子机制，可以用于解释和预测模式。