CAREER: Theoretical Development of Bio-Inspired Water Splitting Photocatalysts

技术摘要：化学系化学催化项目的这一奖项支持了克莉丝汀教授的努力。Aikens和堪萨斯州立大学的研究人员分析了光系统II的放氧中心（OEC）的哪些方面有助于其作为水分解催化剂的有效性，从而预测用于放氧的合成催化剂需要哪些结构和电子方面。 Aikens教授采用了各种电子结构的方法，以实现这一目标，包括：密度泛函理论，二阶微扰理论和多参考方法。 结合量子力学/分子力学（QM/MM）的方法，包括静电嵌入研究的作用，蛋白质或固态载体上的催化活性。 研究的一些问题包括蛋白质骨架对Mn 4Ca核心结构和电荷分布的作用，过渡态能量对预测过电位的影响，精确模拟催化循环所需的适当理论方法，金属氧化物簇，单晶表面和纳米结构支撑物如何改变Mn 4Ca反应中心的电荷分布和效率，以及OEC的化学计量是否在其作为催化剂的有效性中起作用。分子建模软件被纳入堪萨斯州立大学的化学1实验室，以帮助学生学习如何可视化分子几何形状。 每年为中学生举办为期一天的能源和可持续发展研讨会，重点讨论太阳能、生物能源和其他与可再生能源和材料有关的技术等主题。 学生参加介绍性研讨会，并从事动手活动。 这个研讨会旨在包括来自人口稀少地区的农村学生，作为扩大参与科学的一种手段。非技术摘要：这个奖项由化学系的化学催化计划支持教授克莉丝汀M。堪萨斯州立大学的Aikens研究光系统II的氧释放中心（OEC）的各个方面，光系统II是一种复杂的天然蛋白质，它利用光从水中产生氧、电子和氢离子（质子）。 生物系统已经进化出有效的催化剂，用于在光合作用期间分解水以形成氧气，但自然系统通常不会产生氢气。这项理论和计算研究分析了光系统II的氧释放中心的各个方面，这些方面有助于其作为水分解催化剂的有效性。 然后在合成材料中针对类似的方面。 这项研究有助于开发世纪清洁和可再生能源。 分子建模软件被纳入化学1实验室在堪萨斯州立大学，以帮助学生学习如何可视化分子几何形状。 每年为中学生举办为期一天的能源和可持续发展研讨会，重点讨论太阳能、生物能源和其他与可再生能源和材料有关的技术等主题。 参加讲习班的学生参与动手，介绍活动。 该讲习班旨在吸收来自人口稀少地区的农村学生，作为扩大参与科学的一种手段。

Technical Abstract: This award by the Chemical Catalysis Program of the Chemistry Division supports the efforts of Professor Christine M. Aikens of Kansas State University to analyze which aspects of the oxygen-evolving center (OEC) of photosystem II contribute to its effectiveness as a catalyst for water splitting and therefore to predict which structural and electronic aspects are required in synthetic catalysts used for oxygen evolution. Professor Aikens employs a variety of electronic structure methods in order to accomplish this aim including: density functional theory, second-order perturbation theory, and multireference methods. Combined quantum mechanical/molecular mechanical (QM/MM) methods that include electrostatic embedding are employed to examine the role of the protein or solid-state support on catalytic activity. Some of the issues that are studied include the role of the protein backbone on structure and charge distribution in the Mn4Ca core, the impact of transition state energies on predicted overpotentials, the proper theoretical methods required to accurately model the catalytic cycle, how metal oxide clusters, single crystal surfaces, and nanostructured supports change the charge distribution and efficiency of the Mn4Ca reaction center, and whether the stoichiometry of the OEC plays a role in its effectiveness as a catalyst.Molecular modeling software is incorporated into the Chemistry 1 laboratories at Kansas State University in order to help students learn how to visualize molecular geometries. An annual one-day Energy and Sustainability Workshop for middle-school students focuses on topics such as solar power, biological energy, and other technology related to renewable energy and materials. Students attend introductory seminars and engage in hands-on activities. This workshop seeks to include rural students from sparsely populated areas as a means of broadening participation in science.Non-technical Abstract:This award by the Chemical Catalysis Program of the Chemistry Division supports the efforts of Professor Christine M. Aikens of Kansas State University to study aspects of the oxygen-evolving center (OEC) of photosystem II, a complex, naturally-occurring protein which uses light to produce oxygen, electrons and hydrogen ions (protons) from water. Biological systems have evolved efficient catalysts for water splitting to form oxygen during photosynthesis, but natural systems do not normally evolve hydrogen. This theoretical and computational research analyzes aspects of the oxygen-evolving center of photosystem II that contribute to its effectiveness as a catalyst for water splitting. Similar aspects are then targeted in synthetic materials. This research aids in the development of clean and renewable sources of energy for the 21st century. Molecular modeling software is incorporated into the Chemistry 1 laboratories at Kansas State University in order to help students learn how to visualize molecular geometries. An annual one-day Energy and Sustainability Workshop for middle-school students focuses on topics such as solar power, biological energy, and other technology related to renewable energy and materials. Students attending the workshop engage in hands-on, introductory activities. This workshop seeks to include rural students from sparsely populated areas as a means of broadening participation in science.