SusChEM: Artificial Hydrogenases

化学系的生命过程化学项目将这一奖项授予罗切斯特大学的Kara L.Bren教授，以开发和研究钴与多肽的络合物，用于催化利用太阳能从水中生产氢气。氢是一种很有吸引力的燃料，因为它具有高能量密度和清洁燃烧。用电化学方法表征了钴配合物的催化活性。这些催化剂被集成到光化学系统中，将光能转化为化学能。重点研究了反应途径和反应条件对产氢效率和速率的影响。在这个项目中，研究生接受最先进的生化、电化学和光化学技术方面的培训。该奖项还支持罗切斯特国家聋人技术学院的听力障碍学生参与研究，增强科学劳动力的多样性。本项目利用电催化和光催化体系及组装技术，开发新型金属多肽催化剂，并研究水中析氢反应的催化机理。本文研究的金属多肽催化析氢包括一个质子耦合电子转移(PCET)步骤，在该步骤中，多肽胺充当质子穿梭。在这项研究中，Bren教授确定了改变肽序列和胺PKA对PCET的影响，以及对产氢速率和过电位的影响。此外，在工作中研究了缓冲液在向催化剂输送质子方面的作用，对于理解水环境中的催化具有广泛的意义。最后，设计和研究了优化的集成系统，以防止光化学反应中的反电子转移和其他非生产性途径。该项目的成功为以氢燃料形式储存太阳能提供了环境友好的水溶性系统，并进一步加深了我们对催化领域中PCET的理解。这项提议是在SusChEM计划下考虑的，因为它使用了丰富的地球、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).