Career: Catalytic Production of H2 from Water by Molecular Metal Complexes with Pentadentate Ligands

在化学部化学催化项目资助的这个项目中，孟菲斯大学的赵轩教授正在开发新的催化剂，用于从水和阳光中产生氢气（一种重要的化学原料和未来燃料）。为了实现这一点，正在开发基于经济上有吸引力的金属如钴的新催化剂。此外，正在确定催化剂如何发挥作用的细节。这些信息将为形成更有效的材料将水转化为氢提供指导，并可应用于其他潜在的应用，如减少二氧化碳。该项目涉及培训催化科学的本科生和研究生。一个推广计划将为孟菲斯地区的学生和教师提供机会，参加可再生能源研究，并通过周末讲习班，夏季研究机会和当地会议了解太阳能转换和太阳能发电。该项目的中心假设是，金属离子通过在金属上留下一个开放位点的单个多齿配体的络合将产生稳定的金属络合物，该金属络合物对水的光催化还原具有高催化活性。研究主要集中在钴络合物上，初步数据支持这一假设，但也包括其他地球上丰富的金属。除了合成的研究，旨在形成这些配合物与各种配体，正在进行详细的机制调查，以确定质子结合和还原的活性物种，是否H-H形成发生通过均裂或异裂途径，以及控制H2进化机制的一般因素。机械研究正在与布鲁克海文国家实验室的研究科学家合作进行。

In this project funded by the Chemical Catalysis program of the Chemistry Division, Professor Xuan Zhao of the University of Memphis is developing new catalysts for the generation of hydrogen (an important chemical feedstock and future fuel) from water and sunlight. To accomplish this, new catalysts that are based on economically attractive metals such as cobalt are being developed. Additionally, the details of how the catalysts function are being determined. This information will provide a guide to form yet more efficient materials to convert water to hydrogen and may be applied to other potential applications such as the reduction of carbon dioxide. The project involves the training of undergraduate and graduate students in catalytic science. An outreach program will provide Memphis area students and faculty at predominantly undergraduate institutions with opportunities to participate in renewable energy research and to learn about solar energy conversion and photocatalysis through weekend workshops, summer research opportunities and local meetings. The central hypothesis of this project is that the complexation of a metal ion by a single polydentate ligand that leaves one open site on the metal will result in stable metal complexes with high catalytic activity toward the photocatalytic reduction of water. The research centers largely on cobalt complexes for which preliminary data supports the hypothesis, but includes other earth abundant metals. In addition to synthetic studies aimed at forming these complexes with a variety of ligands, a detailed mechanistic investigation is being carried out to determine the active species for proton binding and reduction, whether H-H formation occurs through a homolytic or heterolytic pathway, and the general factors that control the mechanism of H2 evolution. The mechanistic studies are being conducted in collaboration with research scientists at Brookhaven National Laboratory.