CAREER: In-situ Capture and Conversion of CO2 to Hydrocarbons

该奖项全部或部分由《2021年美国救援计划法案》（公法117-2）资助。在过去的几十年里，全球温室气体，二氧化碳（CO2）和甲烷（CH4）的排放量稳步上升，因此迫切需要能够捕获和/或将这些分子转化为高价值化学品的技术。该项目研究了钙钛矿材料在捕获二氧化碳和通过与CH4反应催化其转化为碳氢化合物的双重功能方面的有效性。具体来说，目标是调整钙钛矿的成分，以促进二氧化碳的有效捕获，然后与CH4反应，产生合成气、乙烷和乙烯——所有这些都是重要的平台化学品，可以很容易地转化为聚合物和燃料。因此，该项目探索了一种新的方法，以实现在确保未来能源和化学原料供应的同时减少温室气体排放的目标。该项目将研究与教育和推广计划结合起来，向学生介绍可持续的工程原则，同时扩大和多样化未来的科学和工程劳动力。该项目研究了吸附增强型钙钛矿氧化物催化剂的结构-组成-功能特性，用于通过甲烷干重整（DRM）或二氧化碳介导的甲烷氧化偶联（CO2-OCM）合成碳氢化合物。具体来说，该项目重点关注SrTiO3和CaTiO3，因为它们固有的碱性（促进二氧化碳的吸附），结合它们利用氧空位激活二氧化碳和CH4的能力。研究人员的初步研究已经确定，掺杂Ni的srtio3基多功能催化剂可以捕获二氧化碳并将其转化为合成气、乙烷和乙烯。该项目将使用SrTi1-xMxO3/SrO或CaTi1-xMxO3/CaO （M=Ce， Mn和x = 0 - 0.1）系统选择性吸附模拟理想或烟气混合物中的二氧化碳。具体目标包括：(1)阐明二氧化碳在空气和烟道流中捕获和释放的传输和反应动力学；(2)评价在反应条件下掺杂金属对多功能催化剂的动力学、选择性和稳定性的影响；(3)通过在整体载体上合成钙钛矿基催化剂来提高其表面积。4)通过研究在反应条件下由于金属掺杂析出和/或钙钛矿结构不稳定导致催化剂周期性再生的循环操作，确保催化剂的稳定性。该项目采用了广泛的表征和评估技术，重点是现场和操作高压/高温FTIR和拉曼光谱吸附表面物质（FTIR）和氧空位（拉曼）的表征，后者与石溪大学的T. J. Kim博士合作。将研究与教育和外联倡议结合起来的重点是与化学工程有关的可持续工程概念，特别是在提高妇女在化学工程领域的包容性方面。这些方面的努力将被纳入为研究者所在机构中代表性不足的学生建立的教育和外展计划中。具体来说，研究者计划1)为工程专业的一年级女研究生启动年度研究生准备静修计划，2)为本科生和转学生提供研究经验，3)为K-8女孩开发动手工程活动以解决环境问题，4)扩展本科和研究生化学工程课程。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。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Over the past decades, global emissions of greenhouse gases, carbon dioxide (CO2) and methane (CH4), have risen steadily, thus creating an urgent need for technology capable of capturing and/or converting those molecules to higher-value chemicals. The project investigates the effectiveness of perovskite materials to serve the dual function of capturing CO2 and catalyzing its conversion to hydrocarbons by reaction with CH4. Specifically, the aim is to tune the perovskite composition to promote efficient capture of CO2, followed by reaction with CH4, to produce syngas, ethane, and ethylene - all of value as essential platform chemicals that can be readily converted to polymers and fuels. Thus, the project explores a novel approach to achieving the simultaneous goals of mitigating greenhouse gas emissions while securing future supplies of energy and chemical raw materials. The project integrates the research with an education and outreach plan introducing students to sustainable engineering precepts, while broadening and diversifying the future science and engineering workforce.The project investigates structure-composition-function properties of sorption-enhanced perovskite oxide catalysts for hydrocarbon synthesis via either dry methane reforming (DRM) or CO2-mediated oxidative coupling of methane (CO2-OCM). Specifically, the project focuses on SrTiO3 and CaTiO3 given their inherent basicity (which promotes the adsorption of CO2), combined with their capability to activate CO2 and CH4 using oxygen vacancies. Preliminary studies by the investigator have determined that the SrTiO3-based multifunctional catalysts, doped with Ni, can capture CO2 and convert it to syngas, ethane, and ethylene. The project will use SrTi1-xMxO3/SrO or CaTi1-xMxO3/CaO (with M=Ce, Mn and x = 0 – 0.1) systems to selectivity adsorb CO2 from simulated ideal or flue gas mixtures. Specific goals include: (1) elucidating the transport and reaction kinetics for CO2 capture and release in air and flue streams, (2) evaluating the effects of dopant metals on the kinetics, selectivity, and stability of the multifunctional catalysts under reaction conditions, and (3) enhancing the surface area of the perovskite-based catalysts by synthesizing them on monolith supports, and 4) ensuring the stability of the catalysts by investigating cyclic operation to periodically regenerate the catalysts due to metal-dopant exsolution, and/or perovskite structure destabilization under reaction conditions. The project utilizes a broad range of characterization and evaluation techniques, highlighted by in situ and operando high-pressure/high-temperature FTIR and Raman spectroscopic characterization of adsorbed surface species (FTIR) and oxygen vacancies (Raman), the latter in collaboration with Dr. T. J. Kim at Stony Brook University. Integration of the research with educational and outreach initiatives focuses on sustainable engineering concepts related to chemical engineering, particularly with respect to improving the inclusiveness of women in the chemical engineering field. Efforts along those lines will be incorporated into well-established education and outreach programs for underrepresented students at the investigator’s institution. Specifically, the investigator plans to 1) start an annual graduate preparation retreat program for first-year graduate women in engineering, 2) develop research experience for undergraduate women and transfer students, 3) develop hands-on engineering activities for K-8 girls to solve environmental problems, and 4) expand undergraduate and graduate chemical engineering course curricula.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.