In-situ spectroscopic investigations of Fischer-Tropsch catalysts

目的利用近环境压力x射线光电子能谱（napp - xps）表面敏感光谱技术，原位研究锰促氧化钴催化剂的表面化学性质，以期对催化费托反应的氧化钴催化剂的作用机理有新的认识。特别是，锰的掺杂已被证明有利于催化剂的活性和选择性。目标是：开发一种方法，使其能够使用近环境压力xps研究真正的商业FT催化剂；研究锰掺杂对催化剂还原的影响；研究还原催化剂在水暴露下的表面化学演变；在napp - xps中原位进行费托反应，以阐明活性相的性质；方法学生将使用napp - xps研究催化剂样品由英国石油公司提供。为了补充我们对这些材料的理解，学生也可以基于箔和/或蒸发薄膜开发更简单的模型催化剂。其他互补表征可能包括但不限于：催化测试、红外光谱和拉曼光谱。新的科学内容技术发展对多相催化剂的机理理解通常远远落后于材料的发现，这意味着大多数催化剂都是通过反复试验发现的。通过原位研究催化剂的表面化学性质，我们可以对催化剂的工作原理有一个基本的了解，这将有助于合理设计新的催化剂。开发NAP-XPS方法来原位研究催化剂是其中的一个重要组成部分，可以广泛适用于各种催化系统。了解费托工艺。费托工艺将一氧化碳和氢的原料转化为合成化石燃料（汽油，柴油和煤油）。考虑到需要减少碳排放，这是一个有吸引力的提议，因为原料可以来自可再生资源，如生物质或城市固体废物——有可能实现“绿色”化石燃料。通过详细了解其工作原理来提高FT催化剂的选择性、稳定性和活性，可能是FT作为一种技术被广泛采用的关键。

ObjectivesThis project aims to gain new insight into the mechanisms of operation of Manganese-promoted cobalt oxide catalysts for the Fischer-Tropsch (FT) reaction by using Near-Ambient Pressure X-Ray Photoelectron Spectroscopy (NAP-XPS surface sensitive spectroscopic technique) to study the surface chemistry of the catalyst in-situ. In particular, manganese doping has been shown to be benefical to the catalyst's activity and selectivity, but it is not well understood whyThe objectives are:Develop methodology to be able to study real commercial FT catalysts using Near-Ambient Pressure XPSInvestigate the effect of manganese doping on the reduction of the catalystInvestigate the evolution of the surface chemistry of the reduced catalyst in response to water exposurePerform the Fischer-Tropsch reaction in-situ in NAP-XPS to elucidate the nature of the active phaseApproachThe student will employ NAP-XPS to study catalyst samples supplied by BP. To complement our understanding of these materials, the student may also develop simpler model catalysts based on foils and/or evaporated thin films. Other complementary characterization may include but not be limited to: catalytic testing, Infrared Spectroscopy and Raman SpectroscopyNovel science contentTechnique development Mechanistic understanding of heterogeneous catalysts in general lags far behind materials discovery, meaning that most catalysts are discovered by trial-and-error. By studying the surface chemistry of catalysts in-situ, we can gain fundamental understanding of how they work which will allow the rational design of new catalysts. Developing NAP-XPS methodology to study catalysts in-situ is a vital component of this and could be broadly applicable to diverse catalytic systemsUnderstanding the Fischer-Tropsch processThe FT process converts a feedstock of carbon monoxide and hydrogen into synthetic fossil fuels (gasoline, diesel and kerosene). It is an attractive proposition in light of the need to reduce carbon emissions as the feedstock can come from renewable sources such as biomass or municipal solid waste - potentially enabling "green" fossil fuels. Improving the selectivity, stability and activity of FT catalysts via understanding in detail how they work could hold the key to the widespread adoption of FT as a technology.