CAREER: Nanoparticle Non-Noble Metal Intermetallic Compounds as Tunable Catalysts for Selective Hydrogenation Reactions

该项目将研究新的、低成本的材料，用于催化与提炼石油和生物材料相关的重要化学反应，以生产燃料和各种化学产品。此外，该项目还将探索通过将催化材料合成为纳米颗粒而不是传统的微米级颗粒来提高催化材料有效性的潜力。新材料可以通过许多不同元素的组合而形成，这项研究还将开发预测特定化学反应的最佳元素组合的方法，从而简化催化剂发现过程，并提高美国在燃料和化学品制造行业的竞争力。该项目将与培训下一代工程师的教育和外联工作相联系，并提高公众对燃料电池和电池等新的节能技术的认识。研究人员实验室的初步努力已经建立了对如何以明确的体相和表面成分合成负载型纳米金属间化合物(IMCs)的工作理解。该项目将利用这些发现，系统地研究不饱和醛和硝基化合物选择性加氢过程中组成元素对IMC表面化学的影响。实验和计算方法将被用来考察C=C，C=O和N-O的活化、解离和加氢的选择性与IMC的整体和表面组成以及电子结构信息的函数关系。氧化物支撑的非贵金属纳米IMCs的合成将侧重于清楚地理解决定其本体和表面组成的物理现象，作为元素选择、氧化物选择和制备环境的函数。利用X-射线衍射仪和中子散射仪研究纳米颗粒块体晶体结构的形成。互补的高分辨率能量色散X射线光谱分析将验证整体成分，并对未掺入IMC纳米颗粒的元素进行定量。IMC的表面成分将用低能离子散射进行分析。组成元素的扩散、颗粒生长和大块晶体结构将作为合成变量的函数进行分析，以产生关于如何生产定义明确的纳米IMC的完整图景。这些研究的结果将为IMC催化剂的合成、表征、反应活性评价和稳定性分析提供一个通用的程序。除了目标反应之外，该项目还将使人们能够从原子和电子层面了解纳米颗粒IMC催化如何被控制并广泛用于对多相催化领域至关重要的化学转化。拟议计划的教育部分将用于在诺克斯维尔的田纳西大学开发表面和材料化学教育计划。此外，YouTube视频系列，重点是材料、表面和催化科学，将以一种普通民众可以理解的格式开发，以促进更好地了解这些科学对日常生活的影响。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The project will investigate new, low-cost materials for catalyzing important chemical reactions associated with the refining of petroleum and bio-based materials to produce fuels and a wide range of chemical products. In addition, the project will explore the potential for improving the effectiveness of the catalytic materials by synthesizing them as nanoparticles rather than traditional micron-sized particles. The new materials can be formed through combinations of many different elements, and the study will also develop methods for predicting the best combinations of elements for specific chemical reactions, thereby streamlining the catalyst discovery process and promoting U.S. competitiveness in the fuels and chemicals manufacturing sectors. The project will be linked to educational and outreach efforts that will train the next generation of engineers, and increase public awareness of new energy-efficient technologies such as fuel cells and batteries.Preliminary efforts in the investigator's laboratory have established a working understanding of how supported nanoparticle intermetallic compounds (IMCs) may be synthesized with well-defined bulk and surface compositions. The project will utilize those findings to enable a systematic study of IMC surface chemistry as a function of constituent elements in the selective hydrogenation of unsaturated aldehyde and nitro compounds. Experimental and computational methods will be used to examine the selectivity of C=C, C=O, and N-O activation, dissociation, and hydrogenation as a function of IMC bulk and surface composition and electronic structure information. Synthesis of oxide-supported non-noble metal nanoparticle IMCs will focus on developing clear understanding of the physical phenomena that dictate their bulk and surface composition as a function of element selection, oxide choice, and preparation environment. Formation of the bulk crystal structure of the nanoparticles will be investigated by ex- and in-situ x-ray diffraction and neutron scattering. Complementary high-resolution energy-dispersive x-ray spectroscopy will verify bulk composition and quantify elements not incorporated into the IMC nanoparticles. Surface composition of the IMCs will be analyzed using low energy ion scattering. Diffusion of constituent elements, particle growth, and bulk crystal structure will be analyzed as a function of synthesis variables to produce a complete picture of how well-defined nanoparticle IMCs may be produced. Results of these studies will allow for a general procedure to be developed for the synthesis, characterization, reactivity evaluation, and stability analysis of the IMC catalysts. Beyond the targeted reactions, the project will enable atomic- and electronic-level understanding of how nanoparticle IMC catalysis can be controlled and widely utilized in chemical transformations important to the field of heterogeneous catalysis. The educational component of the proposed program will serve to develop a surface and materials chemistry education program at the University of Tennessee, Knoxville. In addition, a YouTube video series, focused on materials, surface, and catalytic science, will be developed in a format accessible to the general population to promote a greater understanding of the impact these sciences have on everyday life.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.