SusChEM: Electrocatalysis with Butterfly [2Fe-2S] Clusters

作为最简单的分子，氢的生产是一个价值数十亿美元的产业，它提供的氢主要用于与氮结合，生产满足世界人口所需的氨肥，用于从化石燃料中去除硫，以及用于生产现代社会所需材料的工业应用。此外，当今世界面临的重大挑战之一是对可持续、清洁和具有成本效益的能源和燃料的需求。氢是一种高能量燃料，在燃烧时（或在燃料电池中）只产生水作为废气。不幸的是，如今96%的氢气是通过高温高压蒸汽对碳氢化合物的昂贵作用获得的，这一过程既浪费能源又浪费原材料。分析表明，这些过程使用了世界上2%的能源，如果没有使用氢来生产粮食生产所需肥料的过程，世界上一半的人口今天就不会活着。该研究项目由化学部门催化项目资助，正在探索利用电力直接从水中生产氢，这是一种高效、清洁和可持续的过程。为了在低温和低压下实现水制氢，需要一种廉价、易得的催化剂。亚利桑那大学的Dennis L. Lichtenberger、Jeffrey Pyun和Richard S. Glass教授以及普渡大学的Dennis H. Evans教授正在研究利用电和由廉价而丰富的铁和硫组成的催化剂从水中制出氢。本研究中的催化剂受到厌氧细菌中发现的一种酶的启发，这种酶从具有“蝴蝶”结构的[2Fe-2S]簇位点产生氢。类型。虽然酶产生氢的速度非常快，但本项目制备的有机金属蝴蝶[2Fe-2S]簇的速度要快几个数量级。在这个项目中观察到的高产氢率表明，与生物酶和其他无机催化剂相比，有不同的因素在起作用。该项目旨在探索新型有机金属[2Fe-2S]簇催化剂的合成，并研究(1)实现如此快速电催化制氢的机制，(2)将[2Fe-2S]簇纳入金属聚合物中以提高催化剂的水溶性和耐久性，以及(3)实现反应性催化剂在空气中的高稳定性的方法。该项目结合了合成有机金属化学、聚合物化学、电化学和计算化学方面的专业知识，旨在了解从水中设计有效的电催化生产分子氢所需的基本知识，并教育学生在未来应对复杂科学挑战所需的多学科和团队方法。

SusChEM: Electrocatalysis with Butterfly [2Fe-2S] ClustersThe production of hydrogen, the simplest molecule, is a multi-billion dollar industry today that provides hydrogen primarily for combination with nitrogen to produce ammonia fertilizer needed to grow sufficient food for the world population, for removal of sulfur from fossil fuels, and for industrial applications needed to produce the materials for a modern society. Furthermore, one of the grand challenges facing the world today is the need for sustainable, clean, and cost-effective sources of energy and fuels. Hydrogen is a high energy fuel that on burning (or in fuel cells) simply has water as the exhaust product. Unfortunately 96% of the hydrogen produced today is obtained from the expensive action of extremely high temperature and pressure steam on hydrocarbons, a process that is wasteful of both energy and raw materials. Analysis shows that 2% of the world energy is used in these processes and half the world population would not be alive today without the process that uses hydrogen to produce fertilizer for food production. This research project, funded by the Catalysis Program of the Chemistry Division, is exploring the use of electricity to produce hydrogen directly from water in an efficient, clean and sustainable process. To effect the production of hydrogen from water at low temperature and pressure, an inexpensive, readily available catalyst is required. Professors Dennis L. Lichtenberger, Jeffrey Pyun and Richard S. Glass of the University of Arizona and Professor Dennis H. Evans of Purdue University are investigating the production of hydrogen from water using electricity and catalysts composed of inexpensive and plentiful iron and sulfur.The catalysts in this study are inspired by an enzyme found in anaerobic bacteria that produces hydrogen from a [2Fe-2S] cluster site that has a structure denoted as a ?butterfly? type. Although the enzyme generates hydrogen very rapidly, the organometallic butterfly [2Fe-2S] clusters prepared in this project are orders of magnitude faster. The high rates of hydrogen production observed in this project indicate different factors are at play compared to both the biological enzyme and to other inorganic catalysts. This project is exploring the synthesis of new organometallic [2Fe-2S] cluster catalysts and investigating (1) the mechanism that allows for such fast electrocatalytic hydrogen production, (2) the incorporation of the [2Fe-2S] clusters into metallopolymers for increased water solubility and durability of the catalysts, and (3) approaches to achieve high stability of the reactive catalysts in air. The project combines expertise in synthetic organometallic chemistry, polymer chemistry, electrochemistry, and computational chemistry directed toward the fundamental understanding needed to devise efficient electrocatalytic production of molecular hydrogen from water, and educates students in the multidisciplinary and team approaches needed to address complex scientific challenges in the future.