Interaction of Surface and Gas Reactions in High Temperature (max ca. 1300°C) High Pressure (max. ca. 5 M Pa) Catalytic Alkane Oxidations

将天然气中的甲烷、乙烷转化为甲醇、甲醛、乙烯等有价值的化学品是世纪催化研究和化学工程面临的重大挑战。在高温和高压下的多相催化烷烃氧化可能是大规模实现这些转化的一种方式，只要有可能控制催化剂表面和周围气相中的反应之间的相互作用，并使动力学控制的部分氧化产物的形成最大化。通过采用新的原位诊断技术来研究反应温度高达1300 °C和压力高达5 M Pa的表面和气体化学，该项目将有助于在实验研究人员以前未探索的条件下对催化烷烃氧化中的化学和物理表面气体相互作用的机理理解。为了比较不同催化材料上的耦合表面-气体反应的性质和重要性，将研究金属催化剂（Pt）、强碱性耦合催化剂（Li/MgO）和氧化还原催化剂（V Ox）。将使用新开发的毛细管技术和MS或GC物质分析，以µm空间和ms时间分辨率测量无同位素标记和有同位素标记的气体物质、表面和气体温度分布。气相自由基将通过分子束质谱法进行研究。这两种技术都是为这个项目做准备而开发的。空间分辨拉曼光谱与光纤探针将被应用于研究催化剂，气体物种，吸附物种和焦炭沉积。共焦拉曼显微镜将用于绘制催化剂气体边界层，以探索质量和热量传输。数值模拟将进行比较国家的最先进的微动力学表面和气体模型对实验数据，并揭示选择性决定速率参数。如果可能的话，我们将进行改进。通过结合原位实验和数值模拟获得的知识将用于定制催化剂，反应器和反应条件，以获得部分氧化产物的最佳产率。高温高压催化烷烃氧化的动力学的基于知识的控制可以将部分氧化产物的产率推到经济利益的区域，并且可以提高天然气作为化学原料的使用，除了其作为清洁燃料的使用之外。

The transformation of natural gas components like methane and ethane into valuable chemicals like methanol, formaldehyde or ethylene is a big challenge for catalysis research and chemical engineering in the 21st century. Heterogeneous catalytic alkane oxidations at high temperatures and pressures might be a way to accomplish these transformations on a large scale provided that it is possible to control the interaction between reactions at the catalyst surface and in the surrounding gas phase and to maximize the kinetically controlled formation of partial oxidation products. By employing novel in-situ diagnostic techniques to investigate surface and gas chemistry under reaction temperatures up to 1300 °C and pressures up to 5 M Pa, this project will contribute to a mechanistic understanding of chemical and physical surface gas interactions in catalytic alkane oxidations under conditions, largely unexplored by experimental researchers before. To compare nature and importance of coupled surface - gas reactions on different catalytic materials, a metallic catalyst (Pt), a strong basic coupling catalyst (Li/MgO) and a redox catalyst (V Ox) will be investigated. Gas species, surface and gas temperature profiles without and with isotope labelling will be measured with µm spatial and ms time resolution using a newly developed capillary technique with MS or GC species analysis. Gas phase radicals will be studied by molecular beam mass spectrometry. Both techniques have been developed in preparation for this project. Spatially resolved Raman spectroscopy with a fiber probe will be applied to study the catalyst, gas species, adsorbed species and coke deposits. Confocal Raman microscopy will be used to map the catalyst-gas boundary layer to explore mass and heat transport. Numerical simulations will be performed to compare state-of-the-art microkinetic surface and gas models against the experimental data and to reveal selectivity determining rate parameters. If possible, improvements will be made. The knowledge derived by combining in-situ experiments and numerical simulations will be used to tailor catalyst, reactor and reaction conditions for optimum yields of partial oxidation products. A knowledge based control of the kinetics of high temperature high pressure catalytic alkane oxidations could push the yields of partial oxidation products into regions of economic interest and could enhance the use of natural gas as chemical feedstock in addition to its use as a clean fuel.