Mechanisms of Co, Ni, and Mn based water splitting catalysts probed by advanced EPR spectroscopy

来自加州大学戴维斯分校的R.David Britt教授将获得化学系化学催化项目的这一奖项，他将研究一种高效的太阳能水分解催化剂，该催化剂将作为清洁可再生能源技术的基础，产生氢气，这些氢气可以被储存起来，然后再被氧化以在燃料电池中发电，或者用作形成液体燃料的还原中间体。这些研究是基于Kanan和Nocera的发现，即在中性磷酸盐缓冲液中，钴(II)在极化电极表面自发形成裂水催化剂。布里特实验室将使用多频电子顺磁共振波谱来研究这种钴催化剂的结构细节以及它裂解水的机理。将使用CalEPR实验室的连续波(CW)和脉冲EPR仪器，频率范围从8到130 GHz，以及佛罗里达州NHMFL的更高频率仪器。多频电子顺磁共振将用于研究钴催化剂的几何结构和电子结构。脉冲双共振实验(Endor、ESEEM和HYSCORE)将探索钴离子上未配对电子与磁性核(如钴(59)、氧(17)和磷(31))的相互作用，并将结果与已知结构的模型钴配合物进行比较。对硼酸镍类似物的新研究将是对钴膜研究的补充，在Nafion膜中形成的锰催化剂的额外工作将有助于在这些自组装的无机催化剂和重要的光系统II锰放氧络合物之间架起桥梁。理解氢气产生的细节对能源产生至关重要，对激发学生对可再生能源和环境问题的兴趣也很重要。每年，PI都会讲授一般的化学顺序，所涵盖的主题包括：电化学、过渡金属配位化学、化学动力学和光谱学，非常适合将讲座直接与当前在合成和生物系统中利用无机方法分解水和太阳能燃料的研究挂钩。国际和平协会将把这项研究项目的各个方面融入到讲座中。PI计划今年夏天招募几名一年级学生在实验室从事这些课题的工作。此外，他正在教授一门高级仪器分析课程，这将为本科生提供进一步介绍电子顺磁共振(EPR)技术和能源研究的机会。他的研究小组还参与了该部门新的NSF-REU计划，该计划的重点是能源。

With this award from the Chemical Catalysis Program of the Division of Chemistry, Professor R. David Britt from the University of California at Davis will study an efficient solar water splitting catalysis that would serve as the basis of a clean renewable energy technology, producing hydrogen gas, which could be stored and then reoxidized to generate electricity in a fuel cell, or used as a reductive intermediate in forming a liquid fuel. The studies are based on the discovery by Kanan and Nocera that cobalt(II) in neutral phosphate buffer spontaneously forms a water splitting catalyst on a polarized electrode surface. The Britt laboratory will use multifrequency EPR spectroscopy to investigate details of the structure of this cobalt catalyst and the mechanism by which it splits water. Continous wave (CW) and pulsed EPR instruments of the CalEPR laboratory will be used, over a frequency range from 8 to 130 GHz, as well as higher frequency instruments at the NHMFL in Florida. Multifrequency EPR will be used to examine the geometric and electronic structure of the cobalt catalyst. Pulsed double resonance experiments (ENDOR, ESEEM, and HYSCORE) will be probing the interaction of unpaired electrons on the cobalt ions with magnetic nuclei such as cobalt(59), oxygen(17), and phosphorus(31), and the results will be compared with model cobalt complexes of known structure. New studies on nickel borate analogues will be complementing the cobalt film studies, and additional work on a manganese catalyst formed in a Nafion membrane will help in bridging between these self assembled inorganic catalysts and the important Photosystem II Mn oxygen evolving complex.Understanding the details of the production of hydrogen gas is essential for energy generation and it is important to motivate students on renewable energy and environmental issues. Every year the PI teaches an honors general chemistry sequence, and the topics covered; electrochemistry, transition metal coordination chemistry, chemical kinetics, and spectroscopy, are ideally suited to tie lectures directly to current research in inorganic approaches to water splitting and solar fuels, in both synthetic and biological systems. The PI will integrate aspects of this research project into the lectures. The PI plans to recruit several first year students to work in the laboratory on these topics over the summer. In addition, he is teaching an upper division instrumental analysis class, which will provide a further opportunity to introduce undergraduates to electron paramagnetic resonance (EPR) techniques and energy research. His research group is also participating in the department's new NSF-REU program, which has an energy emphasis.