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

AbstractThis项目将调查的因素，控制必要的结构扭曲，以改变介孔氧化物和剥离的纳米片的表面酸性，智能定制这些材料的反应性，有可能作为催化剂，质子导体，和构建块的新型纳米结构材料。我们的目标是测量这些材料的金属氧化物的局部结构和所观察到的表面性质之间的相关性。为了开发这种相关性，固态核磁共振（NMR）方法，采用核磁共振活性同位素的早期过渡金属，钛-47，49和铌-93，作为焦点。 基于由四极核和化学位移各向异性感测的电场梯度的信息，都是由金属周围的原子的排列和结合产生的，用于确定以金属为中心的多面体的局部对称性。 双共振NMR方法将金属原子与吸附物种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，包括课程和实验室，通过建立固态化学、衍射的高级课程以及在化学导论中纳入固态化学实验室模块，增加克拉克大学本科和研究生课程中材料化学的曝光率。关于高表面积材料的结构和表面的详细信息，例如介孔氧化物和剥离的纳米片，对于改善它们作为催化剂、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态NMR方法来表征金属氧化物局部结构与观察到的高表面积剥离或介孔氧化物的表面性质之间的相关性，该方法探测这些材料中的铌和钛环境。 这些结果将作为高比表面积纳米材料的反应性表面结构的优化指导。 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。 私家侦探正在开发材料科学课程，包括课程和实验室，以增加材料化学在克拉克大学的本科和研究生课程中的曝光率，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入门化学。 私家侦探正在与克拉克大学的学术促进办公室指导ALANA（非裔美国人，拉丁美洲人，亚洲人和美洲原住民）和第一代学生的研究机会和职业生涯的要求在化学。

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.