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，并对环境产生负面影响。氢（H2）是一种高能燃料，其在与氧（O2）反应产生水（H2O）时释放能量。传统上，氢是由化石燃料生产的。一些材料可以利用电力或阳光将稳定的化合物（如水）转化为氢气。这些材料被称为催化剂（它们使化学反应更容易进行，而本身不会发生变化）。 确定提高制氢催化剂效率的策略可以对美国的能源独立战略产生有利影响。目前，用于从水中生产氢气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，爱荷华州大学的吉兰博士正在开发新的化学合成方法，以从镍等金属中生产催化剂，这些金属价格较低，更容易在环境中找到。吉兰博士和他的研究生正在研究利用这些催化剂，在电能或光能输入的帮助下，将水分解为氢气的新方法。他们的实验正在提高对这些催化剂如何发挥作用的理解，这将影响有效催化剂设计的未来方向。吉兰正在为本科生和K-12学生创建学习活动，重点是工业重要材料和替代能源工艺，为妇女和代表性不足的群体的学生设计能源研究机会，并改善爱荷华州大学的大学实验室安全文化。吉兰博士的项目由化学催化计划（化学部）和刺激竞争研究的既定计划（EPSCoR）共同资助。在化学系化学催化计划和刺激竞争研究既定计划（EPSCoR）的资助下，爱荷华州大学的Edward Gillan博士正在对过渡金属磷化物与聚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）中的催化活性进行基本了解。Gillan集团的一种简便、无溶剂、热化学驱动的合成策略允许获得地球上丰富的富磷金属磷化物，其MP2和MP3组合物含有Fe、Co和Ni金属。这些结晶金属磷化物直接使用或生长在支撑结构上，用于在电化学和光化学环境中作为HER催化剂进行检测。实验观察到的催化活性的差异与金属磷化物的关键化学，物理和结构特性相关。通过固体核磁共振（NMR）和红外光谱（IR）研究了反应中间体与磷化物表面的结合。P-P键合的结构聚磷化物阴离子的实验影响的背景下，从密度泛函理论（DFT）的材料和键合预测解释。吉兰正在为本科生和K-12学生创造学习活动，重点是工业重要材料和替代能源工艺，为妇女和代表性不足的群体的学生设计能源研究机会，以及改善爱荷华州大学的实验室安全文化。该奖项反映了NSF的法定使命，并被认为值得支持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。

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.