SusChEM: CAREER: High-Resolution X-ray Spectroscopic Studies of Base Metal Catalysis

化学系化学结构、动态和机理B项目获得这一职业奖，资助康奈尔大学化学和化学生物学系的Kyle M.Lancaster教授使用尖端X射线光谱分析来探索富含地球的过渡金属催化剂的反应性。这项研究的目标是确定这些催化剂影响显着化学转化的机制，包括将生物质分解为生物燃料的单糖，以及将天然气转化为可运输的液体形式。了解含有富含地球的金属的催化剂的反应性是可持续化学未来的关键。拟议的工作结合了生物化学、合成、光谱学和理论的元素，为本科生和研究生提供跨学科的培训。光与构成光谱学基础的物质之间的相互作用是该项目推广工作的基础；具体地说，将为K-12学生开发实际操作的“实验室工具包”，以探索光的性质。价到核X射线发射光谱、高能量分辨率荧光检测X射线吸收光谱和共振非弹性X射线散射是表征配位环境和配体电子结构的新的、通用的方法。这些方法被用来探测铜催化剂，这里定义为酶或配位络合物。其中一种待研究的催化剂是一种单核铜酶，它可以氧化裂解生物质中的多糖，如甲壳素和纤维素。停流动力学和快速冷冻淬火方法被用来捕获活性铜-氧物种以进行X射线光谱表征。自然界用于甲烷转化为甲醇的铜催化剂是本研究的重点。这种催化剂是一种完整的膜蛋白，其活性铜氧物种一直无法用常规方法进行研究。努力将扩展到一个非生物系统：铜催化的好氧酒精氧化。这项研究可以证明，所采用的方法不一定需要前催化剂的精确知识来表征反应组成。

With this CAREER award, the Chemical Structure, Dynamic & Mechanism B Program of the Chemistry Division is funding Professor Kyle M. Lancaster of the Department of Chemistry and Chemical Biology at Cornell University to use cutting-edge X-ray spectroscopies to explore the reactivity of earth-abundant transition metal catalysts. The goal of this research is to determine the mechanisms by which these catalysts effect remarkable chemical transformations including the breakdown of biomass to simple sugars for biofuels and the conversion of natural gas to transportable liquid forms. Understanding the reactivity of catalysts incorporating earth-abundant metals is key to a sustainable chemical future. The proposed work incorporates elements of biochemistry, synthesis, spectroscopy, and theory, affording interdisciplinary training for undergraduate and graduate researchers. The interaction between light and matter that forms the basis of spectroscopy is the foundation for outreach efforts under this project; specifically, hands-on "lab kits" are to be developed for K-12 students to explore properties of light.Valence-to-core X-ray emission spectroscopy, high-energy-resolution fluorescence-detected X-ray absorption spectroscopy and resonant inelastic X-ray scattering are emerging, versatile methods to characterize coordination environments and ligand electronic structures. These methods are being used to probe copper catalysts, defined here as either enzymes or coordination complexes. One such catalyst to be studied is a mononuclear copper enzyme that oxidatively cleaves polysaccharides in biomass such as chitin and cellulose. Stopped-flow kinetics and rapid freeze quench methods are being used to trap reactive copper-oxygen species for X-ray spectroscopic characterization. Nature's copper catalyst for conversion of methane to methanol is a focus of this study. This catalyst is an integral membrane protein whose reactive copper-oxygen species have eluded study by conventional methods. Efforts are to be extended to an abiotic system: copper-catalyzed aerobic alcohol oxidation. This study could demonstrate that the methods to be employed do not necessarily require precise knowledge of precatalysts in order to characterize reaction constituents.