直播时间：2024年5月28日（周二）20:00-22:00

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北京时间5月28日晚八点，iCANX Youth Talks第五十七期邀请到了华威大学Peng Wang，新加坡国立大学Qian He，厦门大学Honggang Liao三位教授主讲，北京大学Haixia Zhang教授担任主持人，中国科学院物理研究所Xuefeng Wang担任研讨嘉宾，期待你一起加入这场知识盛宴。

【嘉宾介绍】

Peng Wang

华威大学

Electron Ptychography: An Emerging Imaging Technology for Physical and Biological Sciences

【Abstract】

Coherent diffraction imaging (CDI) and ptychography have been widely used in X-ray synchrotron sources. The advantage of ptychography over traditional CDI is that it does not need prior information about the probe function and overcomes some of the other issues of CDI, such as non-unique solutions and a limited field of view. In electron microscopy, ptychography has also attracted considerable interest due to its potential to achieve super-resolution without using aberration correctors. Unlike conventional imaging modes, the image-forming optics of ptychography replaced by computational methods (like a ‘Digital Lens’) using an array of electron diffractions collected by fast detectors. New generation of direct detection cameras are particularly suited to ptychographic 4D data acquisition with new modes of operation, such as electron counting and fast acquisition. In this talk, I will review the current development and capabilities of this emerging imaging technology (electron ptychography) in my group for light atomic detecting, low dose imaging, 3D reconstruction, coupling to spectroscopy, EM field mapping, and cryogenic EM, which can then tackle characterization challenges across the physical and life sciences, ranging from ferroic and battery materials to biological macromolecules.

相干衍射成像（CDI）和层叠衍射成像（ptychography）已经广泛应用于X射线同步辐射源。与传统的CDI相比，ptychography的优势在于它不需要探针函数的先验信息，并且克服了CDI的一些其他问题，如非唯一解和有限的视野。在电子显微镜领域，ptychography也因其在不使用像差校正器的情况下实现超分辨率的潜力而引起了广泛关注。与传统成像模式不同，ptychography通过计算机算法（如“数字透镜”）处理海量4D电子衍射数据来取代传统的物理光学元件。新一代的直接电子相机可以实现单电子计数和快速采集，特别适合用于ptychography的4D衍射数据采集。在本次报告中，我们将展示ptychography在轻原子检测、低剂量成像、3D重建、与EELS谱仪的耦合、电磁场mapping和冷冻电子显微镜等方面的应用和发展。ptychography的成像能力有望解决物理科学和生命科学中的各种表征挑战，例如铁电和电池材料以及生物大分子。

【BIOGRAPHY】

Peng Wang is an associate professor in the Department of Physics at the University of Warwick in the UK. Since 2012, He has held the position of professor leading a Sub-atomic Resolution Electron Microscopy Laboratory at Nanjing University, China. His research interests and strength have been in the applications of aberration-corrected STEM imaging and EELS to characterize advanced functional materials ranging from ceramics and semiconductors to biological materials and nano-materials, at the nano and atomic scales from two to three dimensions. He has also made pioneering contributions to the field of a technique of 3D imaging materials at the nano-scale using scanning confocal EM performed on a double AC-S/TEM. In addition, one of his current works is focused on the advanced coherent diffractive phase imaging technique, so-called Ptychography. His current research has been focused primarily on two areas: developing novel computational diffractive imaging techniques (ptychography, 4D STEM) for cryogenic electron microscopy (Cryo-EM), light atomic detecting (O, Li elements), low dose imaging (beam sensitive materials), 3D reconstruction and EM field mapping, which can then tackle characterization challenges across the physical and life sciences, ranging from battery materials to biological macromolecules. To date, he has published over 150 refereed journal articles. Google Scholar (H-index 62). He has been named as a Highly Chied Researcher in the Clarivates 2023 list.

王鹏是英国华威大学物理系的副教授，曾在英国国家超高分辨率电镜中心SuperSTEM和牛津大学电镜中心担任研究员。2011-2021年，他回国到南京大学任教，组建了南京大学亚原子分辨透射电子显微镜中心。他的研究兴趣聚焦在开发和应用像差校正的STEM成像和EELS谱学研究陶瓷、半导体、生物材料及纳米材料等先进功能材料，涵盖从二维到三维的纳米和原子尺度结构解析。他在利用双AC-S/TEM进行扫描共焦电子显微镜的纳米尺度3D成像技术领域做出了开创性的贡献。目前，王鹏专注于开发和应用先进的电子相干衍射相位成像技术（Ptychography），并将该技术用于冷冻电子显微镜（Cryo-EM）、轻原子检测（如氧、锂元素）、低剂量成像（束敏材料）以及3D重建和电磁场成像等方向。他申请并获得了多项发明专利，其中包括4件国际专利申请（1件美国授权）和14件中国专利（9件已授权）。截至目前，他已发表了超过150篇同行评审的期刊文章，Google Scholar的H指数为62。2020年，他分别获得了江苏省物理学会科学技术一等奖、江苏省真空学会青年科技奖和江苏省药物研究与开发协会杰出青年奖。他被列入科睿唯安2023年度“高被引科学家”名单。

Qian He

新加坡国立大学

Electron Microscopy for Better Catalysts

【ABSTRACT】

Heterogeneous catalysts are among the unsung heroes of modern society. They are essential in various chemical processes, including the production of fertilizers, fuels, and raw materials, as well as in cleaning air and water pollutants. Even small improvements in these industrial catalysts can lead to significant rewards due to the scale of the relevant industries. Perhaps more importantly, new catalysts are critical for a sustainable future, enabling key chemical processes needed to address sustainability challenges, such as hydrogen production, CO2 conversion, and plastic recycling.

Developing new catalysts materials often requires materials design and engineering at the atomic level, for which modern electron microscopy becomes an indispensable tool. It can be argued that electron microscopy is the only characterization tool that allows us to visualize the atomic structures of practical catalysts directl. In this presentation, I will share recent progress made at the National University of Singapore in developing enhanced catalysts using insights gained from electron microscopy. I will provide examples of Au catalysts and nanoalloy catalysts to demonstrate the power of atomic-scale catalyst design and engineering, and how these development can contribute to our efforts toward a sustainable world.

异质催化剂是现代社会中的无名英雄之一。它们在各种化学过程中起着至关重要的作用，包括肥料、燃料和原材料的生产，以及空气和水污染的净化。由于相关行业的规模，即使这些工业催化剂的微小改进也能带来显著的回报。更重要的是，新型催化剂对于实现可持续未来至关重要，它们能够促进解决可持续发展挑战所需的关键化学过程，例如氢气生产、二氧化碳转化和塑料回收。

开发新催化剂材料通常需要在原子层面进行材料设计和工程，而现代电子显微镜在这一过程中起到了不可或缺的作用。可以说，电子显微镜是唯一能让我们直接观察实际催化剂原子结构的表征工具。在本次报告中，我将分享新加坡国立大学在利用电子显微镜获得的见解来开发增强型催化剂方面取得的最新进展。我将通过金催化剂和纳米合金催化剂的实例，展示原子级催化剂设计和工程的强大功能，以及这些研究如何助力我们实现可持续发展的目标。

【BIOGRAPHY】

Qian He is an Assistant Professor in the Department of Materials Science and Engineering at the National University of Singapore. He graduated with a bachelors and masters degree from Tsinghua University, China in 2008 and obtained his Ph.D. in Materials Science and Engineering from Lehigh University in 2013. From 2013 to 2016, he conducted postdoctoral research at Oak Ridge National Laboratory in the United States. Between 2016 and 2019, he was an University Research Fellow in the Department of Chemistry at Cardiff University in the United Kingdom. He has published over 160 papers in high-impact journals, including Science, Nature Catalysis, Nature Synthesis, Nature Communications, and JACS. His research group is focused on the development and application of electron microscopy techniques, particularly in the areas of catalysts and functional nanomaterials. As of June 2024, his work has been cited over 11,000 times, with an H-index of 60. Qian He has received the Singapore NRF Fellowship award and the Outstanding Postdoctoral Award from the Microscopy Society of America, among other accolades.

何迁，新加坡国立大学材料科学与工程系助理教授。何迁于2008年在清华大学本科和硕士毕业，此后于2013 年在美国Lehigh大学获得材料科学与工程博士学位。2013年到2016年期间，曾在美国橡树岭国家实验室进行博士后研究。2016年到2019年在英国卡迪夫大学化学院任教。他在一些高影响力期刊上已发表超过160余篇论文，其中包括Science, Nature Catalysis, Nature Synthesis, Nature Communications, JACS等刊物。他的课题组正致力于电子显微技术的开发和应用，特别是在催化剂和功能纳米材料方向。截止2024年6月，他的工作已被引用超过11000 余次，H指数高达60。何迁曾获新加坡NRF Fellowship资助，曾获美国电子显微学会优秀博士后奖等。

Honggang Liao

厦门大学

Liquid Phase TEM

【ABSTRACT】

Transmission electron microscopy is currently the most efficient characterization tool for atomic scale imaging. However, the electrons microscopy works at high vacuum mode and high-resolution imaging of controllable reactions in gas or liquid remains a great challenge.We have developed various in-situ transmission electron microscopy chip reactor and control systems, and thus achieved real-time imaging of dynamic reaction at atomic scale. A dense phase was identified at solid liquid interface, the dynamics and transportation of ions in dense phase was tracked. A new mechanism of charge storage and collective reaction in lithium sulfur batteries has been discovered for the first time, revealing the existence of a new mechanism besides the traditional electrochemical interface "inner sphere reaction" and "outer sphere reaction" mechanisms, providing guidance for the design of next-generation batteries. In situ liquid phase electron microscopy can provide high-resolution real-time imaging at the atomic/molecular scale, and obtain information of solid-liquid interface structure and valence states, which provides a new perspective for in-depth research of chemistry, materials and applications.

透射电镜是目前在原子尺度上研究物质微观结构最高效的表征手段之一，但电镜光路系统需要置于高真空中,模拟真实反应氛围和条件的可控反应（如液体和常压气体环境中）高分辨成像依然是极大的挑战。自主开发研制了多种原位透射电镜芯片反应器和控制系统，将气液体流场、电光热力控制与测量引入纳米芯片反应器，实现了多个反应体系的原子尺度实时成像及动态反应过程追踪。实现了原子分辨固液界面动态成像，发现界面富集相新结构。探究电化学界面反应过程，首次发现了锂硫电池电荷存储聚集反应新机制，揭示出在传统的电化学界面“内球反应”和“外球反应”机制外存在第三种“电荷存储聚集反应”新机制，为下一代电池设计提供指导。原位液相电镜可从原子分子尺度高分辨实时成像并获取相关材料电化学固液界面结构及价态的高空间分辨率信息，从而使微观领域研究从静态跨入动态的新阶段，为深入研究化学、材料基础及应用提供了一个新的视角。

【BIOGRAPHY】

Honggang Liao is “Minjiang scholar professor” in Xiamen university. His research focus on the development of in-situ electron microscopy technology and its application in material science, energy storage and conversion processes. He has published over 100 papers in high-impact journals including Science, Nature, and more than 40 patents. He developed series of in-situ chips and holder systems, which have been widely used in fundamental research and industry applications. Early research on crystal growth by in-situ liquid phase transmission electron microscopy has been reported as "Shaping the Future of Nanocrystal". A new mechanism of charge storage-collective reaction mechanism in lithium sulfur batteries has been discovered for the first time, which providing guidance for the design of next-generation batteries. Currently serving as member of the Committee of China Energy Society and Commission of Polymer Analysis and Characterization, and the chief supervisor of Xiamen University Alumni Association Entrepreneurship Branch. Received the 12th China Chemical Society BASF Youth Knowledge Innovation Award (2023), and the research "Discovering a New Mechanism of Interface Charge Storage-Collective Reaction in Lithium Sulfur Batteries" was selected as one of the "Top 10 Scientific Advances in China" in 2023.

廖洪钢，厦门大学教授。致力于原位电镜技术开发及其在材料、化学中的应用。完成了早期原位液相电镜晶体生长过程的示范性研究，成果两次在Science上发表论文，被评论为“Shaping the future of nanocrystal”。首次发现了锂硫电池中“电荷存储聚集反应”新机制，为下一代电池设计提供指导。在Science、Nature等刊物上发表论文100余篇，专利、软著40余件。目前担任中国能源学会专家委员会委员，中国化学会高分子材料分析技术与表征方法专业委员会委员。获第十二届中国化学会-巴斯夫公司青年知识创新奖（2023），研究成果“发现锂硫电池界面电荷存储聚集反应新机制”入选2023年度“中国科学十大进展”。

【主持人】

Haixia Zhang

北京大学

【研讨嘉宾】

Xuefeng Wang

中国科学院物理研究所