SusChEM: Rational Design and Synthesis of Stable Strain- and Defect-Rich Cu/Ceramic Nanocomposites for Efficient CO2 Reduction

非技术性总结：在该项目中，由材料研究部陶瓷计划支持，Tewodros Asefa教授正在开发新型纳米颗粒，其中含有夹在两种金属氧化物之间的缺陷和应变丰富的铜纳米晶体。这些材料正被用于研究铜纳米晶体的稳定性和催化活性，用于将二氧化碳（一种温室气体）转化为甲醇（一种合成燃料和商品化学品）。虽然富含缺陷和应变的铜纳米晶体对这种化学转化具有高催化活性，但不幸的是，这些位置也是不稳定的，因此很容易失去活性。这个问题是克服了纳米材料的设计，包括金属氧化物核和多孔金属氧化物壳周围的应变和缺陷丰富的铜纳米晶体。这种独特的结构允许纳米晶体保留其催化超活性位点，同时保持稳定，并允许在高温下（用于将二氧化碳转化为甲醇的条件）系统研究铜纳米晶体的结构和催化性能之间的相互作用。国家标准与技术研究所（NIST）高分辨率中子散射中心（CHRNS）的最先进的高分辨率中子散射技术正在用于破译纳米颗粒上的缺陷和应变以及它们在催化过程中可能发生的任何变化。CHRNS的仪器可以对正在开发的材料的结构和动力学进行各种独特的表征。技术规格：虽然最近已经发现铜纳米晶体上的缺陷和应变位点对于二氧化碳到甲醇的高温化学转化具有高催化活性，但不幸的是，这些位点也是化学不稳定的，因此在这些条件下容易发生烧结和失活。该研究的主要特点是设计核-壳纳米粒子，其包含夹在金属氧化物核和多孔金属氧化物壳之间的稳定且高活性、缺陷和应变丰富的铜纳米晶体，并使用所得纳米催化剂来提供对铜和其他相关金属纳米材料在高温催化条件下的结构-性能关系的透彻理解。这种铜纳米晶体的合成是通过一种称为受控配体辅助蚀刻的方法进行的。该研究最终揭示了需要在铜和其他相关金属纳米材料中定制的关键结构因素，以有效催化各种反应，包括将二氧化碳转化为甲醇，或将温室气体转化为合成燃料或商品化学品。此外，该项目还提供一名研究生和三名或三名以上本科生的培训，包括那些来自历史上在科学和工程领域代表性不足的群体的学生。参加这项研究的学生获得跨学科的实践培训，使用罗格斯表面改性实验室提供的基础设施以及NIST提供的各种材料合成方法，催化和材料表征。此外，研究结果将被纳入研究生课程，解决可持续和可再生能源应用的材料工程。

NON-TECHNICAL SUMMARY: In this project, supported by the Ceramics Program in the Division of Materials Research, Professor Tewodros Asefa is developing novel nanoparticles containing defect- and strain-rich copper nanocrystals sandwiched between two metal oxides. These materials are being used to investigate the stability and catalytic activity of copper nanocrystals for the conversion of carbon dioxide (a greenhouse gas) to methanol (a synthetic fuel and a commodity chemical). While defect- and strain-rich copper nanocrystals have high catalytic activity for this chemical conversion, these very sites are also unfortunately unstable, and thus can easily lose their activity. This problem is overcome by the design of nanomaterials that comprise metal oxide cores and porous metal oxide shells around the strain- and defect-rich copper nanocrystals. This unique structure allows the nanocrystals to retain their catalytically super-active sites, while remaining stable and allowing for the systematic investigation of the interplay between the structures and catalytic properties of copper nanocrystals under high temperature (the condition used for converting carbon dioxide to methanol). State-of-the-art high-resolution neutron scattering techniques at the Center for High Resolution Neutron Scattering (CHRNS) in the National Institute of Standards and Technology (NIST) are being used to decipher the defects and strains on the nanoparticles and any changes that they may undergo during catalysis. The instrumentation at CHRNS allows for various unique characterizations of the structure and dynamics of the materials being developed. TECHNICAL DETAILS: While defect and strained sites on copper nanocrystals have been recently found to have high catalytic activity for high temperature chemical conversion of carbon dioxide to methanol, these very sites are also unfortunately thermodynamically unstable, and thus can easily undergo sintering and deactivation under these conditions. Key features of the research are the designing of core-shell nanoparticles containing stable and highly active, defect- and strain-rich copper nanocrystals sandwiched between metal oxide cores and porous metal oxide shells, and using the resulting nanocatalysts to provide a thorough understanding of the structure-property relationships of copper and other related metallic nanomaterials under high temperature catalytic conditions. The synthesis of such copper nanocrystals is carried out by a method called controlled ligand-assisted etching. The research ultimately uncovers key structural factors that need to be tailored in copper and other related metallic nanomaterials for the efficient catalysis of various reactions, including the conversion of carbon dioxide to methanol, or a greenhouse gas to a synthetic fuel or a commodity chemical. Additionally, the project provides training of a graduate student and three or more undergraduate students, including those from groups historically underrepresented in science and engineering. The students participating in this research gain interdisciplinary, hands-on training with a variety of materials synthetic methods, catalysis, and materials characterization using the infrastructure available at the Rutgers Laboratory for Surface Modification, as well as that available at NIST. Furthermore, the results from the research will be incorporated into graduate course offerings that address materials engineering for sustainable and renewable energy applications.