INFEWS N/P/H2O: Collaborative Research: Catalytic Dephosphorylation Using Ceria Nanocrystals

磷是维持生命的关键元素，在农业中具有重要的经济意义。然而，目前磷肥的生产依赖于消耗磷矿等有限的原料。在化学系化学催化项目的资助下，约翰霍普金斯大学的王超博士和路易斯安那州立大学的徐叶博士正在合作开发被称为多相催化剂的化学品，这种催化剂可以促进可再生生物质的除磷，以产生可用于合成化肥的磷。在王超博士的团队中，结合了先进的合成技术、X射线和分子光谱表征以及催化研究，探索了基于尺寸在0.00000005英寸数量级的稀土氧化物“纳米晶”的新型脱磷催化剂。与此同时，叶旭博士的团队使用密度泛函理论(DFT)为这些催化剂创建了原子尺度的理论模型，以计算控制反应速度和能源消耗的反应路径和势垒。除磷工艺的最新进展。实验和理论方法相结合，以加深对催化机理的基本理解。王博士和徐博士都积极参与了促进科学、技术、工程和数学(STEM)学科教育的外展计划。这些调查人员将本科生纳入他们的研究，并参与了与当地学校的接触。王教授通过巴尔的摩小学(Sabes)的STEM成就项目和巴尔的摩的其他学校，以及大学的女性科学与工程(WISE)项目，一直积极参与该项目。徐教授与路易斯安那州科学与工程博览会竞赛和当地学校合作。这项研究开发了创新和可再生的磷(P)生产方法。这一点很重要，因为磷是维持生命的关键元素，广泛用于对现代农业实践至关重要的化肥生产。为了应对这一挑战，约翰·霍普金斯大学的王超博士和路易斯安那州立大学的徐叶博士正在合作探索使用CeO2纳米晶体催化脱磷。通过将先进的纳米材料合成、X射线和分子光谱表征、催化研究和密度泛函理论(DFT)计算相结合，该项目识别了重要的CeO2表面结构，如晶面和缺陷(Ce3阳离子和氧空位)，并对它们进行了系统的评估，以建立结构-性质关系和识别活性中心。首先以对硝基苯基磷酸盐(p-NPP)和单甲基磷酸酯(MP)为模型分子，对反应动力学进行了全面的研究，然后将研究推广到各种类型的磷酸酯分子，包括芳基和烷基磷酸盐、核苷酸和磷脂。这项研究能够有效地从生物质中回收磷，用于可再生的磷生产。然后，这些磷可以用于生产经济和高产农业所必需的化肥。这项工作获得了关于CeO2催化剂结构-性质关系的新的基础知识，特别是在纳米级和水溶液环境中。这两名调查人员正在积极参与促进科学、技术、工程和数学(STEM)学科教育的外联计划。这些活动包括培训研究生掌握最先进的实验和理论技能，发展他们的独立研究哲学，为本科生提供科学和工程研究前沿的实践经验，以及邀请不同背景的初中生作为暑期实习生在调查实验室工作。

Phosphorus (P) is a crucial element for sustaining life and is economically important in agriculture. The current production of P fertilizers, however, relies on depleting limited feedstocks such as phosphate rocks. With funding from the Chemical Catalysis Program of the Chemistry Division, Dr. Chao Wang from Johns Hopkins University and Dr. Ye Xu from Louisiana State University are collaborating to develop chemicals, known as heterogeneous catalysts, which promote the removal f phosphorus of renewable biomass to produce phosphorous which can be used to synthesize fertilizers. In Dr. Chao Wang's group, advanced synthesis techniques, X-ray and molecular spectroscopic characterization, and catalytic studies are combined to explore novel dephosphorylation catalysts based on rare-earth oxide "nanocrystals" whose dimensions are on the order of 0.00000005 inches. Meanwhile, Dr. Ye Xu's group creates atomic -scale theoretical models for these catalysts using density function theory (DFT) to calculate the reaction pathways and barriers that control the reaction rates and energy consumption. of the phosphorus removal processes. The experimental and theoretical approaches are integrated to develop fundamental understanding of the catalytic mechanisms. Both Dr. Wang and Dr. Xu are actively engaged in outreach programs for promotion of education in the science, technology, engineering and mathematics (STEM) disciplines. These investigators have incorporated undergraduate students in their research and are involved in outreach with local schools. Professor Wang has been active through a STEM Achievement program in Baltimore Elementary Schools (SABES) project and with other schools in Baltimore in addition to the Woman in Science and Engineering (WISE) program at the university. Professor Xu works with the Louisiana State Science and Engineering Fair competition and local schools. This research develops innovative and renewable methods for phosphorus (P) production. This is important because phosphorous is a crucial element for sustaining life and is widely employed in fertilizer production crucial to modern agricultural practices. To tackle this challenge, Dr. Chao Wang from Johns Hopkins University and Dr. Ye Xu from Louisiana State University are collaborating to explore catalytic dephosphorylation using ceria nanocrystals. By integration of advanced nanomaterial synthesis, X-ray and molecular spectroscopic characterization, catalytic studies and density functional theory (DFT) calculations, the project identifies the important ceria surface structures, such as crystal facets and defects (cerium cation (Ce3+) and oxygen vacancies), and systematically evaluates them to establish the structure-property relationships and identify the active sites. Para-nitrophenyl phosphate (p-NPP) and monomethyl phosphate (MP) are first used as model molecules to perform comprehensive studies of the reaction kinetics, and the studies are then generalized to various types of phosphate ester molecules, including aryl and alkyl phosphates, nucleotides and phospholipids. The research enables the efficient recovery of phosphorus from biomass for the renewable production of phosphorus. This phosphorus can then be used in the production of fertilizers that are necessary for economical and productive agriculture. This work gains new, fundamental knowledge about the structure-property relationships of the ceria catalysts, particularly at the nanoscale and in aqueous solution environment. The two investigators are actively engaged in outreach programs for promotion of education in the science, technology, engineering and mathematics (STEM) disciplines. These activities include training graduate students with state-of-the-art experimental and theoretical skills and developing their independent research philosophy, providing undergraduate students with hands-on experiences at the cutting edge of science and engineering research, and engaging middle- and high-school students from diverse backgrounds to work in the investigators' laboratories as summer interns.