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，为在受控温度和连续气体气氛而不是通常的高真空条件下进行动态原位反应研究提供埃分析。新设计提供了世界上第一台全功能像差校正环境扫描透射电子显微镜（AC ESTEM）。与充满活力的英国化学和能源行业的合作伙伴合作，我们将产生基础应用科学，支持气固反应中基于纳米颗粒的固态多相催化。我们将修改现有的 AC TEM/STEM 仪器，以补充和扩展国家 AC STEM 设施在高真空下的卓越图像和能量分辨率的气体反应研究。它将通过 AC STEM 用于约克项目以及与其他团体的合作项目。它建立在 PI 在 ETEM 领域建立的全球领导地位的声誉之上，迄今为止，大部分全球活动（全部在海外）基于超过 10 个高分辨率 ETEM，其中许多是 AC（仅在 TEM 图像侧），并使用核心技术从作者早期的发展来看。初步“原理验证”已在约克的远程控制双像差校正 JEOL 2200FS TEM/STEM 上进行了演示；结合了亚埃 (<0.1nm) 分辨率、不受限制的 HAADF Z 对比度 STEM 成像、广角电子衍射和 EDX (+ EELS) 化学分析，这些在 ETEM 上不可用。双像差校正在单个且通常可直接解释的 TEM 图像中收集接近零散焦的全范围空间频率，以最大限度地减少晶界、外表面、缺陷和其他关键不连续性等内部界面处的图像离域。这对于数据不断变化的动态原位研究尤其重要，这使得旧的全焦系列重建方法变得不切实际。 AC 还改变了 STEM 分析的灵敏度。这项工作将使用通过“冷冻”和过程提取的样品建立的分析方法，并将其应用于以新的灵敏度和相关性水平研究连续过程。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；但它们在温度或化学环境等条件下可能是亚稳态的，因此无法通过异位或脉冲研究获得。一个非常实际的例子是负载型金属纳米颗粒非均相催化剂的纳米结构和相关性能稳定性，其中得到了英国领先工业界的兴趣和支持。通过合成、活化、操作、失活、再活化和恢复机制，从根本上理解对于在合理的基础上管理工业实践以实现持续的活性和选择性至关重要；并在必要时恢复丢失的这些关键属性。该项目方向与现实世界学术和工业应用的领域科学需求紧密结合，并且有支撑关键技术的早期采用前景；包括延长有用的流程生命周期。例如，这对于燃料电池更广泛的商业可行性至关重要。该提案得到了充满活力且具有国际竞争力的化学工业领域的领先英国公司以及学术合作者的支持。与此同时，基础领域科学的新知识也致力于在环境中开辟具有紧迫社会价值的新应用。基础物理科学研究与战略和战术工业应用相结合，带来了差异化的智力产品，其举措在英国独一无二，在全球具有充分的竞争力。该项目将扩展和应用核心纳米颗粒催化科学技术，并培训一批新的学生、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