Development and Applications of Aberration Corrected Environmental STEM (AC ESTEM) for Dynamic In-Situ Reaction Studies of Nanoparticle Catalysts

用于纳米颗粒催化剂动态原位反应研究的像差校正环境 STEM (AC ESTEM) 的开发和应用

基本信息

批准号：
EP/J018058/1
负责人：
Pratibha Gai
金额：
$ 174.95万
依托单位：
University of York
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2012
资助国家：
英国
起止时间：
2012 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FJ018058%2F1
关键词：
Development Applications Aberration Corrected Environmental

项目摘要

We propose to create in the UK a novel research capability providing Angstrom Analysis for dynamic in-situ reaction studies under controlled conditions of temperature and continuous gas atmosphere rather than the usual high vacuum. The new design provides the world's first full function aberration corrected environmental scanning transmission electron microscope (AC ESTEM). In association with partners in the vibrant UK chemical and energy industries we will generate fundamental application science underpinning nanoparticle based solid state heterogeneous catalysis used in gas-solid reactions. We will modify an existing AC TEM/STEM instrument to complement and extend with gas reaction studies the National AC STEM Facility's superior image and energy resolutions in high vacuum. It will be used in York programmes and collaborative projects with other groups through the AC STEM. It builds on the PIs' established reputations for global leadership in ETEM, with most of the worldwide activity to date - all overseas - based on >10 high resolution ETEMs and many of them AC (on the TEM image side only), using core technology from the authors' earlier developments. Preliminary 'proof-of-principle' has been demonstrated on the remotely controlled double aberration corrected JEOL 2200FS TEM/STEM at York; combining sub-Angstrom (<0.1nm) resolution, unrestricted HAADF Z-contrast STEM imaging, wide angle electron diffraction and EDX (+ EELS) chemical analysis not available on ETEMs. The double aberration correction collects, in a single and often directly interpretable TEM image, a full range of spatial frequencies at close to zero defocus to minimise image delocalisation at internal interfaces such as grain boundaries, external surfaces, defects and other key discontinuities. This is especially important for dynamic in-situ studies with continuously changing data making impractical older through-focal series reconstruction methods. AC also transforms the sensitivity of STEM analysis. The work will use analytical methods established with 'frozen' and process extracted samples, and apply them to the study of continuous processes at new levels of sensitivity and relevance. Access to key intermediate states and phases may be critical to understand and control process mechanisms; but they may be metastable with respect to conditions, including temperature or chemical environment, and therefore not accessible through ex-situ or pulse studies. A very practical example, in which there is leading UK industry interest and support, is the nano-structure and related property stability of supported metal nanoparticle heterogeneous catalysts. Through synthesis, activation, operation, deactivation, reactivation and recovery mechanisms, understanding at a fundamental level is critical for managing on a rational basis industrial practice for sustained activity and selectivity; and where necessary recovering these key attributes when lost. The project direction is closely aligned with the domain science needs of real world academic and industrial applications, and there are early adoption prospects for underpinning key technologies; including to extend useful process life cycles. For example, this is critical for the wider commercial viability of fuel cells. The proposal has the support of leading UK companies in the vibrant and internationally competitive chemical industry sector, and of academic collaborators. At the same time, the new learnings in basic domain science are also directed towards opening up new applications of pressing societal value in the environment. Fundamental physical science research with strategic and tactical industrial applications leads to differentiated intellectual products with an initiative unique in the UK and fully competitive globally. The project will extend and apply core nanoparticle catalysis science and technology, and train a new cohort of students, postdocs, senior staff and visitors.

我们建议在英国创建一种新颖的研究能力，为在温度和连续气气的受控条件下，而不是通常的高真空度提供了动态原位反应研究的Angstrom分析。新设计提供了世界上第一个全功能畸变校正的环境扫描传输电子显微镜（AC Estem）。与充满活力的英国化学和能源行业的合作伙伴联合，我们将产生基于纳米颗粒的基础科学，基于纳米颗粒的基础固态异质催化，用于气体固体反应。我们将修改现有的AC TEM/Stem仪器，以补充和扩展气体反应研究国家AC STEM设施在高真空中的优越图像和能量分辨率。它将通过AC STEM与其他团体一起用于约克计划和协作项目。它建立在PIS在ETEM中为全球领导力的既定声誉建立的，迄今为止，大多数全球活动 - 所有海外的活动 - 基于> 10个高分辨率ETEM，其中许多AC（仅在TEM图像方面）使用了作者较早的发展中的核心技术。在约克的远程控制的双重畸变校正后，已经证明了初步的“原理证明”。结合了亚角（<0.1nm）分辨率，无限制的HAADF z对比茎成像，广角电子衍射和EDX（+ EELS）化学分析在ETEM上不可用。双重畸变校正以单个且通常是直接可解释的TEM图像收集，在接近零散焦时的整个空间频率都可以最大程度地减少内部接口的图像离域化，例如晶粒边界，外表面，缺陷和其他关键不连续性。这对于通过不断变化的数据的动态原位研究尤其重要，这使得不切实际的较旧的焦距串联重建方法。 AC还改变了茎分析的灵敏度。这项工作将使用使用“冷冻”和过程提取的样品建立的分析方法，并将其应用于新的灵敏度和相关性水平的连续过程。访问关键的中间状态和阶段对于理解和控制过程机制可能至关重要。但是它们在包括温度或化学环境在内的条件方面可能是可稳定的，因此无法通过前静脉或脉冲研究获得。在英国领先的行业兴趣和支持中，一个非常实用的例子是纳米结构和相关的财产稳定性的纳米纳米颗粒异质催化剂的稳定性。通过综合，激活，操作，停用，重新激活和恢复机制，在基本水平上的理解对于以合理的基础工业实践来管理持续活动和选择性至关重要。在必要时，丢失时恢复这些关键属性。项目的方向与现实世界学术和工业应用的领域科学需求紧密相符，并且在基础关键技术的基础上有早期的采用前景。包括扩展有用的过程生命周期。例如，这对于燃料电池的更广泛的商业生存能力至关重要。该提案得到了英国领先的公司在充满活力和国际竞争性化学工业领域以及学术合作者的支持。同时，基本领域科学中的新学习还旨在开放新的应用程序，以迫使社会价值在环境中。具有战略和战术工业应用的基本物理科学研究会导致差异化的智力产品在英国具有独特的计划，并且在全球范围内具有完全竞争力。该项目将扩展和应用核心纳米粒子催化科学技术，并培训新的学生，博士后，高级职员和访客。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Visualisation of single atom dynamics in water gas shift reaction for hydrogen generation

DOI：
10.1039/c5cy01154j
发表时间：
2016-04
期刊：
Catalysis Science & Technology
影响因子：
5
作者：
P. Gai;Kenta Yoshida;M. Ward;M. Walsh;R. T. Baker;L. V. D. Water;M. J. Watson;E. Boyes
通讯作者：
P. Gai;Kenta Yoshida;M. Ward;M. Walsh;R. T. Baker;L. V. D. Water;M. J. Watson;E. Boyes

In-situ environmental (scanning) transmission electron microscopy of catalysts at the atomic level