CAREER: Surface Crystallization of Reactive Oxygen Permeable Hydroxyapatite-based Membranes for Direct Methane Oxidative Conversion

1351384-LiuAbstractCAREER：用于甲烷直接氧化转化的反应性透氧羟基磷灰石基膜的表面结晶PI的职业目标是创造创新的催化剂和膜技术，实现活性和选择性的化学转化，特别关注氯和生物质原料的催化转化。目的是建立基于活性氧(O2)可渗透羟基磷灰石(HAP)的甲烷氧化偶联成C2碳氢化合物的膜。虽然催化膜反应器领域已经出现了用于OCM的固体氧化物膜，但获得高的C2产率仍然是一个挑战，这与膜材料的催化和氧气渗透性能之间的协调密切相关。表面结晶控制膜纳米结构(组成和组成)的独特方法将使薄而致密的膜具有足够的甲烷活化和氧气渗透性能。铅和碳酸盐取代的羟基磷灰石(PbHAP-CO3)分别具有良好的OCM催化性能和高透氧率，是目前HAP膜研究的热点。本研究的基本原理是系统地控制Pb2+和CO32-的组成(Pb2+和CO32-浓度)和组成(厚度和晶体取向)，以调整其催化和传输性能，从而在OCM中实现CH4的协同活化和O2的渗透以生产C2。这项研究引人注目的方面是，它提供了一种具体的战略，以创造将低成本甲烷转化为增值燃料和化学品的新的、潜在的变革性方法。皮？S的教育目标是为学生提供学习经验，这些学习经验将导致成功地培养下一代科学家和工程师，特别是在材料合成、催化和能源领域。这项研究将材料科学和化学工程方面的广泛培训融入到为各级学生提供的研究经验和教育计划中。具体来说，这包括：(I)基于皮？S对材料、催化、分离和能源的研究兴趣，为本科生和研究生开发一门新课程；(Ii)为所有级别的学生提供研究经验；以及(Iii)面向K-12学生和普通公众受众的外展计划。这些教育活动已经在进行中，并与PI的部门和学院的目标很好地结合在一起。智力优势：在膜反应器中通过OCM反应获得高C2产率的潜在挑战是缺乏具有协调的催化和透氧性能的膜材料。该项目将专注于基础研究，以实现高效OCM工艺的活性氧透透膜的出现。这些研究活动将促进人们对(I)通过受控表面结晶方法操纵膜纳米结构，(Ii)膜纳米结构对管式反应器中甲烷反应和氧气传输动力学的影响，以及(Iii)材料合成-结构-功能对OCM性能的预测关系的理解。从这项工作中获得的基本概念和技术将刺激和开辟材料发现和技术开发的新途径，这些材料和技术可能会影响世界未来的能源和化学品供应。广泛的影响：将甲烷加工成高附加值的化学品和燃料是科学和社会面临的巨大挑战之一。高效的OCM膜反应器的开发将导致新的热化学过程，以满足对来自甲烷气体的高能量密度和可替代燃料/化学品的需求，以应对这一挑战。拟议的方案将材料科学和化学工程的研究与教育和宣传部分结合起来，旨在突出这些学科在能源转换领域的重要性。教育将通过开发一门基于材料、催化、分离和能源方面的研究兴趣的新课程，通过招募和指导研究活动中代表性不足的社区的学生，以及通过针对马里兰州乔治王子县(UMD所在的)K-12学生和普通公众受众的外联计划来加强。

1351384 - LiuAbstractCAREER: Surface Crystallization of Reactive Oxygen Permeable Hydroxyapatite-based Membranes for Direct Methane Oxidative ConversionThe PI's career goal is to create innovative catalyst and membrane technologies that enable active and selective chemical conversions with particular focus on the catalytic conversion of C1 and biomass feedstock. The objective is to establish reactive oxygen (O2) permeable hydroxyapatite (HAP)-based membranes for oxidative coupling of methane (OCM) to C2 hydrocarbons. While the field of catalytic membrane reactors has emerged solid oxide membranes for OCM, attaining high C2 yield, which intimately depends on the harmonization between the catalytic and O2 permeable properties of the membrane materials has remained a challenge. The unique approach of surface crystallization in controlling the membrane nanostructures (composition and constitution) will enable thin and dense membranes possessing sufficient methane activation and O2 permeation properties for OCM. Lead and carbonate substituted HAP (Pb-HAP-CO3) is the focus on the HAP-based membranes because Pb2+ and CO32-, respectively, endow a single HAP with good catalytic properties for OCM and high permeance for O2 transport. The rationale of this research is to systematically manipulate the composition (Pb2+ and CO32- concentration) and constitution (thickness and crystal orientation) of the Pb-HAP-CO3 membranes to tune their catalysis and transport properties, and thus, to achieve cooperative CH4 activation and O2 permeation in OCM for C2 production. The compelling aspect of this research is that it offers a specific strategy to create new and potentially transformative ways of converting low cost methane to value-added fuels and chemicals.The PI?s educational goal is to provide learning experiences for students that will lead to success in educating the next generation of scientists and engineers, particularly in the fields of materials synthesis, catalysis, and energy. The research incorporates broad training in materials science and chemical engineering into research experiences and education programs for students at all levels. Particularly, this includes: (i) a new course development for educating undergraduates and graduates based on the PI?s research interests in materials, catalysis, separation, and energy; (ii) research experiences for students at all levels; and (iii) outreach programs for K-12 students and general public audiences. These educational activities are already in progress, and are well aligned with the goals of the PI's department and college.Intellectual Merit: The underlying challenge in attaining high C2 yield from OCM reactions in membrane reactors is the scarcity of membrane materials with harmonized catalytic and oxygen permeable properties. This project will focus on fundamental studies to enable the emergence of reactive-oxygen permeable membranes for efficient OCM processes. The research activities will advance the understanding of (i) manipulation of membrane nanostructures by controlled surface crystallization approach, (ii) effects of membrane nanostructures on methane reaction and oxygen transport kinetics in tubular reactors, and (iii) predictive correlations of materials synthesis-structure- function for OCM performance. The fundamental concepts and technologies obtained from this work will stimulate and open new avenues of material discovery and technique development that can impact future energy and chemical supplies of the world.Broader Impact: The processing of methane to derive highly value-added chemicals and fuels is one of the enormous challenges faced by science and society. The development of efficient OCM membrane reactors will lead to new thermochemical processes to meet the demand for high-energy density and fungible fuels/chemicals from methane gas to address this challenge. The proposed program integrates research on materials science and chemical engineering with an education and outreach component designed to highlight the importance of these disciplines in the area of energy conversion. Education will be enhanced by developing a new course based on the research interests in materials, catalysis, separation, and energy, by recruiting and mentoring students from under-represented communities in research activities, and by outreach programs for K-12 students and general public audience in Prince George's County, MD (where UMD is located).