SusChEM: Investigation of a Core-Shell Redox Catalyst Platform for Oxidative Dehydrogenation of Ethane

SusChEM：乙烷氧化脱氢核壳氧化还原催化剂平台的研究

• 批准号: 1604605
• 负责人: Fanxing Li
• 金额: $ 44.99万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1604605&HistoricalAwards=false
• 关键词: SusChEM; Investigation; Core; Shell; Redox

The project will investigate the oxidative dehydrogenation (ODH) of ethane to produce ethylene - a high volume chemical intermediate. A novel approach is employed that utilizes a core-shell catalyst design in combination with a chemical looping redox cycle to achieve ODH without direct feed of oxygen. The combined approach potentially eliminates a costly and energy-intensive process for separating oxygen from air, while also reducing carbon emissions. The work will provide multi-disciplinary educational opportunities for graduate and undergraduate students, as well as outreach activities to high school students and teachers for stimulating interest in STEM careers.The core-shell redox catalyst is both an active catalyst and an effective lattice oxygen ion donor for ethane ODH in a chemical-looping scheme. The work plan tests three key hypotheses: 1) Chemically and structurally compatible primary (cobalt/iron) oxides and perovskites can be assembled into a stable core-shell arrangement for ethane ODH under a cyclic redox mode; 2) The surface properties of the core-shell redox catalyst can be tailored by tuning the metal cation oxidation state and defect structure of the mixed ionic-electronic conductor (MIEC) shell, rendering a highly effective catalyst for ethane ODH in the absence of gaseous oxidants; 3) Ethane ODH reaction occurs primarily on the perovskite surface via homolytic C-H bond cleavage through a modified Mars-van Krevelen mechanism. To test these hypotheses, phase-compatible core and shell materials will be identified and then assembled into core-shell particles. The effects of perovskite A-site and B-site substitutions on ODH activity and selectivity will be investigated and correlated to the defect structure and cation oxidation state of the shell material. Kinetic and mechanistic aspects will be investigated over pellets and thin films replicating the core-shell and shell structures using in-situ Raman and FT-IR/DRIFTS, a molecular beam reactor coupled with an X-ray photoelectron spectrometer, and pulse isotope studies. The studies will potentially result in fundamentally new materials and schemes that can significantly improve the efficiency for ethylene production from natural gas while reducing emissions.

该项目将研究乙烷氧化脱氢（ODH）生产乙烯-一种高容量的化学中间体。 采用了一种新的方法，该方法利用核-壳催化剂设计与化学链氧化还原循环相结合来实现ODH而无需直接进料氧气。 这种组合方法可能消除了从空气中分离氧气的昂贵和能源密集型过程，同时还减少了碳排放。 这项工作将为研究生和本科生提供多学科的教育机会，并为高中学生和教师提供外展活动，以激发他们对STEM职业的兴趣。核壳氧化还原催化剂既是化学循环方案中乙烷ODH的活性催化剂，也是有效的晶格氧离子供体。 工作计划测试三个关键假设：1）化学和结构相容的主要（钴/铁）氧化物和钙钛矿可以在循环氧化还原模式下组装成稳定的乙烷ODH核壳结构; 2）核-壳氧化还原催化剂的表面性质可以通过调节混合离子-电子导体（MIEC）壳的金属阳离子氧化态和缺陷结构来定制，在不存在气态氧化剂的情况下提供用于乙烷ODH的高效催化剂; 3）乙烷ODH反应主要在钙钛矿表面上通过经修改的Mars-van Krevelen机理的均裂C-H键断裂发生。为了测试这些假设，相相容的核和壳材料将被识别，然后组装成核-壳颗粒。 将研究钙钛矿A位和B位取代对ODH活性和选择性的影响，并将其与壳材料的缺陷结构和阳离子氧化态相关联。动力学和机制方面将研究超过丸和薄膜复制的核壳和壳结构，使用原位拉曼和FT-IR/DRIFTS，分子束反应器耦合的X射线光电子能谱仪，和脉冲同位素研究。这些研究可能会产生全新的材料和方案，可以显着提高天然气生产乙烯的效率，同时减少排放。