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材料，用于催化与石油和生物基材料精炼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形成，该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领域的竞争力。 该项目将与教育和推广工作相联系，以培养下一代工程师，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工作已经建立了一个工作理解，即如何合成具有明确本体和表面组成的支撑纳米颗粒金属间化合物（IMC）。 该项目将利用这些发现，系统地研究IMC表面化学，作为不饱和醛和硝基化合物选择性氢化中组成元素的函数。实验和计算的方法将被用来检查的选择性的C=C，C=O，和N-O的活化，解离，和氢化作为IMC体和表面组成和电子结构信息的函数。 氧化物支撑的非贵金属纳米颗粒IMC的合成将集中在发展的物理现象，决定其作为元素选择，氧化物的选择和制备环境的函数的体积和表面组成的清晰的理解。的纳米粒子的大块晶体结构的形成将通过前和原位X射线衍射和中子散射进行研究。互补的高分辨率能量色散X射线光谱将验证本体组成和量化未纳入IMC纳米粒子的元素。将使用低能离子散射分析IMC的表面组成。扩散的组成元素，颗粒生长，和散装晶体结构将作为一个功能的合成变量进行分析，以产生一个完整的图片如何定义的纳米颗粒IMC可以生产。这些研究的结果将允许开发用于IMC催化剂的合成、表征、反应性评估和稳定性分析的通用程序。 除了目标反应之外，该项目还将使人们能够在原子和电子水平上了解纳米颗粒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在田纳西大学诺克斯维尔开发一个表面和材料化学教育计划。 此外，还将制作一个YouTube视频系列，重点关注材料、表面和催化科学，并以大众可访问的格式进行开发，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知识价值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.