Mitigation of Pervasive Haber Process Carbon Pollution: Ammonia synthesis from air and water in suspensions of nanoscale Fe/Fe2O3

化学系的环境化学科学项目将通过该奖项资助乔治华盛顿大学的Stuart Licht教授，以发展生产氨的基础科学，氨是生产肥料的关键原料。这个过程利用空气、水和阳光，不会产生含碳的副产品。目前，哈伯法生产氨通过肥料生产有效地养活了世界人口；然而，这个过程是能源密集型的，每年向大气中释放超过2亿吨的二氧化碳。哈伯合成氨的引入与世界人口从1930年的20亿到今天的70亿的爆炸性增长同步。在这个研究项目中，正在开发一种替代化学工艺，用于从氮气、水和热能中生产氨。还需要常见的材料（熔融氢氧化物，Ni电极）和廉价的纳米级Fe/Fe2O3催化剂。更广泛的影响包括在可再生能源领域，特别是在太阳能合成领域培训研究生。该提案旨在探索电解和太阳能合成途径，以生产肥料急需的氨。light研究小组最近发现，利用纳米级Fe2O3悬浮液在熔融氢氧化物中电解，可以在不含二氧化碳的情况下，以高达70%的库仑效率从大气氮中生产氨。这个过程在高温下需要很少的能量。使用STEP（太阳能热电化学过程），当太阳光提供热能时，产生氨而不排放任何二氧化碳。该项目旨在通过探索机制、寻求增加过程活性和优化太阳能耦合来提高对这种新的合成氨合成途径的基本基础的理解。研究了水加空气转化为氨的界面电化学，改变了纳米级催化剂的结构，探索了太阳能（STEP）氨的原型，包括新的太阳能加压路线，以进一步提高太阳能效率。

With this award, the Environmental Chemical Sciences Program of the Division of Chemistry is funding Professor Stuart Licht of George Washington University to develop the fundamental science of a process to produce ammonia, a critical feedstock for the production of fertilizer. This process utilizes air, water and sunlight, without creating carbon-containing byproducts. Currently, the Haber process to produce ammonia effectively feeds the world population through fertilizer production; however, this process is energy intensive, releasing over 200 million tons of carbon dioxide to the atmosphere each year. Introduction of Haber synthetic ammonia has paralleled the explosive increase in world population from 2 billion in 1930 to 7 billion today. In this research program, an alternative chemical process is being developed for the production of ammonia from N2, water and thermal energy. Also needed are common materials (molten hydroxide, Ni electrodes) and an inexpensive, nanoscale Fe/Fe2O3 catalyst. The broader impacts include the training of graduate students in the field of renewable energy, specifically in the domain of solar synthesis.This proposal is an effort to explore electrolytic and solar synthetic pathways to produce critically needed ammonia for fertilizer. The recent discovery in the Licht research group of this alternative chemistry for the production of ammonia from atmospheric nitrogen produces ammonia without carbon dioxide and at up to 70% coulombic efficiency by electrolysis in molten hydroxide using suspensions of nanoscale Fe2O3. The process requires little energy at high temperature. With STEP (Solar Thermal Electrochemical Process), when the thermal energy is provided by sunlight, ammonia is produced without emission of any carbon dioxide. The project seeks to improve understanding of the fundamental basis of this new synthetic pathway to produce ammonia by exploring the mechanism and seeking to increasing the activity of the process and optimize the solar energy coupling. The interfacial electrochemistry of the water plus air conversion to ammonia is being probed, the architecture of nanoscale catalyst is being varied and a solar (STEP) ammonia prototype is to be explored, including a new solar pressurized route, to further increase solar energy efficiency.