SusChEM: Artificial Hydrogenases

化学部门的生命过程化学项目将此奖项授予罗切斯特大学的卡拉·l·布伦教授，以开发和研究利用太阳能从水中催化氢气生产的钴与肽的复合物。氢是一种有吸引力的燃料，因为它的高能量密度和清洁燃烧。用电化学方法对钴配合物的催化活性进行了表征。这些催化剂被集成到光化学系统中，用于将光能转化为化学能。重点研究了反应途径及反应条件对产氢效率和速率的影响。在这个项目中，研究生接受了最先进的生化、电化学和光化学技术的培训。该奖项还支持罗切斯特国家聋人技术研究所的听障学生参与研究，提高科学劳动力的多样性。本项目开发新型金属肽催化剂，利用电催化和光催化系统和组件研究水中析氢反应的催化机理。本研究中研究的金属肽催化析氢涉及质子偶联电子转移（PCET）步骤，其中肽胺充当质子穿梭者。在这项研究中，brenn教授确定了改变肽序列和胺pKa对PCET的影响，以及对氢气生成速率和过电位的影响。此外，缓冲液在将质子输送到催化剂中的作用也被研究，这对理解水环境中的催化作用具有广泛的意义。最后，设计和研究了集成系统，以防止光化学反应中的反电子转移和其他非生产性途径。该项目的成功为氢燃料形式的太阳能存储提供了环保的水溶性系统，并进一步发展了我们对PCET催化的理解。该方案是在SusChEM计划下考虑的，因为它使用了地球丰富的非贵金属催化剂（钴）。

The Chemistry of Life Processes Program in the Chemistry Division is making this award to Professor Kara L. Bren of the University of Rochester to develop and investigate complexes of cobalt with peptides for catalyzing the production of hydrogen gas from water using solar energy. Hydrogen is an attractive fuel because of its high-energy density and clean combustion. The catalytic activity of the cobalt complex is characterized using electrochemistry. These catalysts are integrated into photochemical systems for converting light energy to chemical energy. Investigations of reaction pathways and the effects of reaction conditions on the efficiency and rate of hydrogen production are emphasized in this research. Graduate students are trained in state-of-the-art biochemical, electrochemical, and photochemical techniques in this project. This award also supports the participation of hearing-impaired students from the National Technical Institute for the Deaf in Rochester in research, enhancing scientific workforce diversity. This project develops new metallopeptide catalysts and investigates catalytic mechanisms for the hydrogen evolution reaction in water, using electro-catalysis as well as photocatalytic systems and assemblies. Catalysis of hydrogen evolution by the metallopeptides studied in this work involves a proton-coupled electron transfer (PCET) step in which the peptide amine acts as a proton shuttle. In the research, Professor Bren determines the effects of altering peptide sequence and amine pKa on PCET and on the rate and overpotential for hydrogen production. In addition, the role of buffers in delivering protons to the catalyst is investigated in work with broad implications for understanding catalysis in an aqueous environment. Finally, integrated systems optimized to prevent back electron transfer and other unproductive pathways in the photochemical reaction are engineered and investigated. Success in this project provides environmentally friendly, water-soluble systems for the storage of solar energy in the form of hydrogen fuel and further develops our understanding of PCET in catalysis. This proposal is considered under the SusChEM program as it uses earth abundant, non-precious metal catalysts (cobalt).