CAREER: Iron Complexes for Hydrogen Generation and Oxygen Reduction

SusChEM：职业：铁络合物用于制氢和氧气还原清洁和可持续能源的发展是现代社会面临的最紧迫的问题之一。太阳能是地球上最丰富的可再生能源形式，但受到不连续供应的限制。因此，开发一种利用和储存太阳能作为与我们现有基础设施兼容的能量密集型化学燃料的方法至关重要。通过一种称为人工光合作用（AP）的过程，阳光被利用并用于将水分解为氧气和氢气。氢气直接用作燃料，或者在氢燃料电池中与氧气结合以发电。由于昂贵的材料和低效的催化剂，通过AP产生氢气比从化石燃料产生的氢气昂贵得多。使用氢燃料电池将太阳能燃料转化为电能也受到使用昂贵材料（铂）的限制。在这个项目中，威廉·R. McNamara设计了一种使用成本效益高的铁催化剂的光催化制氢系统。还研究了在氢燃料电池中使用廉价的铁催化剂来有效还原氧气。在该项目内，开展了若干外联活动，以促进未来几代科学家的发展。麦克纳马拉博士正在当地一所公立高中开展课外活动，那里的科学、技术、工程和数学（STEM）领域的代表性不足。通过该计划，学生积极地以有意义和可访问的方式进行研究。这些活动促进了公众的科学素养，同时鼓励代表性不足的群体追求STEM学科的职业生涯。McNamara在威廉和玛丽学院致力于开发用于光催化制氢和氢燃料电池氧还原反应的廉价材料。利用衰减全反射红外光谱（ATR-IR）和漫反射紫外-可见光谱（UV-Vis）表征了在电荷分离载体（碳纳米管、TiO 2和SrTiO 3）上固定化的稳健铁多吡啶基制氢催化剂。氢气的产生是促进使用LED光解系统和气相色谱分析。为了降低成本，提高光催化制氢的广泛适用性，使用天然存在的腐殖物质，以取代传统的牺牲供体也进行了研究。此外，铁聚吡啶亚磺酸盐催化剂在氢燃料电池中的氧还原反应进行了检查。采用旋转环盘伏安法（RRDV）和循环伏安法（CV）评价催化剂的性能。为了更好地理解机制，还采用了使用波脚分析（FOWA）的数据的严格处理。来自NSF的资金提供了15个不同的学生（主要是本科生）在这个多学科的研究工作的培训。此外，麦克纳马拉博士在当地一所公立高中开展了一项课后研究计划，该学校高度集中了科学领域代表性不足的群体。与该项目的广泛影响相一致，这些活动促进了STEM学科中代表性不足的群体的参与，并增加了公众对科学的参与。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

SusChEM: CAREER: Iron Complexes for Hydrogen Generation and Oxygen ReductionThe development of clean and sustainable energy is one of the most pressing issues facing modern society. Solar energy is the most abundant form of renewable energy on earth, but is limited by a discontinuous supply. It is therefore critical to develop a way to harness and store solar energy as an energy dense chemical fuel that is compatible with our current infrastructure. Through a process called artificial photosynthesis (AP), sunlight is harnessed and used to split water into oxygen and hydrogen gas. Hydrogen gas is used directly as a fuel, or is combined with oxygen in a hydrogen fuel cell to generate electricity. Owing to expensive materials and inefficient catalysts, hydrogen generation through AP is significantly more expensive than hydrogen generated from fossil fuels. The use of hydrogen fuel cells to convert solar fuels into electricity is also limited by the use of expensive materials (platinum). In this project, Dr. William R. McNamara devises a photocatalytic system for hydrogen generation using cost-effective iron catalysts. The use of inexpensive iron catalysts for the efficient reduction of oxygen gas in hydrogen fuel cells is also investigated. Within this project, several outreach activities promote the development of future generations of scientists. Dr. McNamara is conducting an after-school program at a local public high school with a high concentration of underrepresented groups in science, technology, engineering, and mathematics (STEM). Through this program students actively conduct research in a meaningful and accessible way. These activities advance public scientific literacy while encouraging underrepresented groups to pursue careers in STEM disciplines.Funding from the Chemical Catalysis Program of the National Science Foundation supports the effort of Dr. William R. McNamara at the College of William and Mary towards the development of inexpensive materials for both photocatalytic hydrogen generation and the oxygen reduction reaction of hydrogen fuel cells. The immobilization of robust iron polypyridyl hydrogen generation catalysts on charge-separating supports (carbon nanotubes, TiO2 and SrTiO3) is characterized using attenuated total reflection infrared spectroscopy (ATR-IR) and diffuse reflectance UV-Vis spectroscopy. Hydrogen generation is promoted using an LED photolysis system and analyzed with gas chromatography. In order to decrease cost and improve the widespread applicability of photocatalytic hydrogen generation, the use of naturally occurring humic substances to replace traditional sacrificial donors is also investigated. Additionally, iron polypyridyl sulfinate catalysts are examined for the oxygen reduction reaction in hydrogen fuel cells. Rotating ring disk voltammetry (RRDV) and cyclic voltammetry (CV) are used to evaluate catalytic performance. Rigorous treatment of the data using foot-of-the-wave analysis (FOWA) is also employed to better understand mechanism. Funding from the NSF provides for the training of 15 different students (primarily undergraduates) in this multi-disciplinary research effort. Additionally, Dr. McNamara conducts an after-school research program at a local public high school with a high concentration of underrepresented groups in science. Consistent with the broader impacts of this project, these activities promote the engagement of underrepresented groups in STEM disciplines and increase public engagement in the sciences.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.