CAREER: Solid State NMR Studies of Transition Metal Oxides: Correlation of Local Structure with Physical Properties

职业：过渡金属氧化物的固态核磁共振研究：局部结构与物理性质的相关性

• 批准号: 0748399
• 负责人: Luis Smith
• 金额: $ 53万
• 依托单位: Clark University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-02-15 至 2014-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0748399&HistoricalAwards=false
• 关键词: CAREER; Solid; State; NMR; Studies

AbstractThis project will investigate factors that control the structural distortions necessary to alter the surface acidity of mesoporous oxides and exfoliated nanosheets to intelligently tailor the reactivity of these materials which have the potential to serve as catalysts, proton conductors, and building blocks for novel nanostructured materials. The goal is to measure the correlation between the metal oxide local structure and the observed surface properties of these materials. To develop this correlation, solid-state Nuclear Magnetic Resonance (NMR) methodologies are employed using the NMR active isotopes of early transition metals, titanium-47, 49 and niobium-93, as the focal point. Information based on the electric field gradient sensed by a quadrupolar nucleus and the chemical shift anisotropy, both created by the arrangement and bonding of atoms surrounding the metal, is used to determine the local symmetry of the metal-centered polyhedra. Double resonance NMR methods correlate the metal atoms with adjacent elements present in adsorbed species to distinguish surface sites and probe the interaction strengths of the surface sites. The project will introduce and train undergraduate and graduate students in the issues and methods associated with materials science research. The P.I is developing materials science curricula, both courses and labs, to increase the exposure of materials chemistry in the undergraduate and graduate programs at Clark University through the establishment of upper-level courses in solid-state chemistry, diffraction, and the incorporation of solid-state chemistry lab modules in introductory chemistry.%%%Detailed information about the structure and surface of high surface area materials, such as mesoporous oxides and exfoliated nanosheets, is necessary to improve their performance as catalysts, proton conductors, and building blocks for novel nanostructured materials. The aim of this project is to characterize the correlation between the metal oxide local structures and the observed surface properties of high surface area exfoliated or mesoporous oxides through solid-state NMR methods that probe the niobium and titanium environments in these materials. These results will serve as a guide for optimization of reactive surface structures in high surface area nanomaterials. The project will introduce and train undergraduate and graduate students in the issues and methods associated with materials science research. The P.I. is developing materials science curricula, both courses and labs, to increase the exposure of materials chemistry in the undergraduate and graduate programs at Clark University through the establishment of upper-level courses in solid-state chemistry, diffraction, and the incorporation of solid-state chemistry lab modules in introductory chemistry. The P.I. is working with the Academic Advancement Office of Clark University to mentor ALANA (African American, Latino, Asian and Native American) and first generation students on the research opportunities available and the requirements of careers in chemistry.

摘要本项目将研究控制结构扭曲的因素，这些扭曲是改变介孔氧化物和剥离纳米片表面酸度所必需的，以智能地调整这些材料的反应性，这些材料有潜力作为催化剂、质子导体和新型纳米结构材料的基石。目的是测量金属氧化物局部结构与观察到的这些材料表面特性之间的相关性。为了发展这种相关性，采用固态核磁共振（NMR）方法，使用早期过渡金属的核磁共振活性同位素，钛-47,49和铌-93作为焦点。基于四极核感应的电场梯度和金属周围原子排列和成键产生的化学位移各向异性的信息，用于确定金属中心多面体的局部对称性。双共振核磁共振方法将金属原子与吸附物质中存在的相邻元素相关联，以区分表面位点并探测表面位点的相互作用强度。该项目将介绍和培训本科生和研究生与材料科学研究相关的问题和方法。P.I正在开发材料科学课程，包括课程和实验，通过建立固态化学、衍射的高级课程，以及在化学入门课程中加入固态化学实验模块，在克拉克大学的本科和研究生课程中增加材料化学的曝光。关于高表面积材料的结构和表面的详细信息，如介孔氧化物和剥离纳米片，对于提高它们作为催化剂、质子导体和新型纳米结构材料的构建块的性能是必要的。该项目的目的是通过固体核磁共振方法探测这些材料中的铌和钛环境，表征金属氧化物局部结构与观察到的高表面积剥落或介孔氧化物表面性质之间的相关性。这些结果将为高表面积纳米材料反应性表面结构的优化提供指导。该项目将介绍和培训本科生和研究生与材料科学研究相关的问题和方法。P.I.正在开发材料科学课程，包括课程和实验，以增加材料化学在克拉克大学本科和研究生课程中的曝光，通过建立固态化学、衍射的高级课程，并将固态化学实验室模块纳入化学入门课程。P.I.正在与克拉克大学的学术进步办公室合作，指导ALANA（非洲裔美国人，拉丁裔，亚裔和美洲原住民）和第一代学生在化学领域的研究机会和职业要求。