CAS: Investigation of Earth-Abundant Metal Phosphides with Polyphosphide Anions as Catalysts in Hydrogen Evolution Reactions

随着社会的繁荣，能源和燃料的消耗也在增长。然而，我们对化石燃料的依赖是不可持续的，并且会对环境产生负面影响。氢（H2）是一种高能燃料，与氧（O2）反应生成水（H2O）时释放能量。传统上，氢是由化石燃料产生的。一些材料可以利用电力或阳光将稳定的化合物（如水）转化为氢。这些材料被称为催化剂（它们使化学反应更容易进行而不改变自身）。确定提高催化剂效率以生产氢气的策略可以对美国的能源独立战略产生有利影响。目前，从水中生产氢的最活跃的催化剂使用昂贵和稀有的金属，如铂。在这个项目中，爱荷华大学的吉兰博士正在开发一种新的化学合成方法，从镍等金属中生产催化剂，这种催化剂更便宜，更容易在环境中找到。吉兰博士和他的研究生们正在研究利用这些催化剂在电力或光能输入的帮助下将水分解成氢的新方法。他们的实验提高了对这些催化剂如何起作用的理解，这影响了有效催化剂设计的未来方向。Gillan博士正在为本科生和K-12学生创建学习活动，专注于工业重要材料和替代能源过程，为女性和代表性不足的学生设计能源研究机会，并改善爱荷华大学的大学实验室安全文化。吉兰博士的项目是由化学催化计划（化学部）和建立计划刺激竞争研究（EPSCoR）共同资助的。爱荷华大学的爱德华·吉兰博士在化学系化学催化项目和刺激竞争研究既定项目（EPSCoR）的资助下，正在研究过渡金属磷化物与多磷化物阴离子的表面反应和氧化还原化学如何影响其在重要的析氢反应（HER）中的催化活性。Gillan团队采用了一种简单的、无溶剂的、热化学驱动的合成策略，可以利用含有铁、钴和镍金属的MP2和MP3成分获得地球上丰富的富磷金属磷化物。这些结晶金属磷化物在电化学和光化学环境中作为HER催化剂直接使用或生长在支撑结构上进行研究。实验观察到的催化活性差异与金属磷化物的关键化学、物理和结构性质有关。利用固体核磁共振（NMR）和红外光谱（IR）研究了反应中间体与磷化物表面的结合。在密度泛函理论（DFT）的材料和键预测的背景下，解释了结构聚磷酸盐阴离子中P-P键的实验影响。为了支持该项目更广泛的影响，吉兰博士正在为本科生和K-12学生创建学习活动，重点关注工业重要材料和替代能源过程，为女性和弱势群体的学生设计能源研究机会，并改善爱荷华大学的大学实验室安全文化。该奖项反映了美国国家科学基金会的法定使命，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。

Energy and fuel consumption grow as society prospers. However, our reliance on fossil fuels is not sustainable and negatively impacts the environment. Hydrogen (H2) is a high energy fuel that releases energy upon its reaction with oxygen (O2) to produce water (H2O). Traditionally, hydrogen is produced from fossil fuels. Some materials can convert stable compounds, like water, into hydrogen using electricity or sunlight. These materials are known as catalysts (they make it easier to perform a chemical reaction without themselves being changed). Identifying strategies to increase catalyst efficiency to produce hydrogen can favorably impact US energy independence strategies. Currently, the most active catalysts for the production of hydrogen from water use expensive and rare metals like platinum. In this project, Dr. Gillan of the University of Iowa is developing new chemical syntheses to produce catalysts from metals such as nickel that are less expensive and more easily found in the environment. Dr. Gillan and his research students are examining new ways to split water into hydrogen using these catalysts aided by electricity or light energy input. Their experiments are improving understanding of how these catalysts function, which impacts future directions in effective catalyst design. Dr. Gillan is creating learning activities for undergraduate and K-12 students focused on industrially important materials and alternate energy processes, designing energy research opportunities for women and students from under-represented groups, and improving university laboratory safety culture at the University of Iowa. Dr. Gillan's project is jointly funded by the Chemical Catalysis Program (Division of Chemistry) and by the Established Program to Stimulate Competitive Research (EPSCoR). With funding from the Chemical Catalysis Program of the Division of Chemistry and by the Established Program to Stimulate Competitive Research (EPSCoR), Dr. Edward Gillan of the University of Iowa is developing a fundamental understanding of how surface reactions and redox chemistry of transition-metal phosphides with polyphosphide anions impact their catalytic activity in the important hydrogen evolution reaction (HER). A facile, solvent-free, thermochemically-driven synthetic strategy by the Gillan group allows access to earth-abundant phosphorus-rich metal phosphides with MP2 and MP3 compositions containing Fe, Co, and Ni metals. These crystalline metal phosphides are used directly or grown on supported structures for examination as HER catalysts in both electrochemical and photochemical environments. Experimentally observed differences in catalytic activity are correlated with key chemical, physical, and structural properties of the metal phosphides. The binding of reaction intermediates to the phosphide surface is investigated by solid-state nuclear magnetic resonance (NMR) and infrared spectroscopy (IR). The experimental impact of P-P bonding in structural polyphosphide anions is interpreted in the context of materials and bonding predictions from density functional theory (DFT). In support of the broader impacts of this project, Dr. Gillan is creating learning activities for undergraduate and K-12 students focused on industrially important materials and alternate energy processes, designing energy research opportunities for women and students from under-represented groups, and improving university laboratory safety culture at the University of Iowa.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.