Zeolite Nanosheet on Hydrogen Permeable Membrane: Coupling Catalysis with Hydrogen Removal in Non-oxidative Direct Methane Conversion

由于固有的动力学和热力学约束，甲烷非氧化直接转化（NDMC）为更有价值且易于运输的化学品和燃料仍然是一个巨大的挑战。 美国能源情报署最近的一份报告设想，廉价而丰富的天然气作为一种原材料，可以显著影响世界的化学和能源供应。 由金属/沸石（Mo/ZSM 5）催化剂和氢气（H2）可渗透膜组成的膜反应器具有克服这些动力学和热力学障碍的潜力。 膜反应器的基本特征是，在空间上受约束的ZSM 5通道内的Mo物质含有布朗斯台德酸位点，活化甲烷以形成碳链，同时限制碳链长度; H2可渗透膜连续地去除H2产物以相对于进料平衡限制增加转化率。 本研究的主要目的是制备和描述由ZSM 5层状催化剂和薄的H2渗透陶瓷膜组成的新型管式膜反应器。 研究的一个重点是通过组装ZSM 5纳米片和陶瓷膜来控制ZSM 5晶体尺寸，以优化NDMC中的甲烷（CH 4）反应动力学和H2分离。 初步的数据表明，Mo/ZSM 5和H2渗透通过陶瓷膜的活性强烈地依赖于ZSM 5的晶体尺寸和膜厚度，分别。 跨学科的战略将被用来控制NDMC，并创造新的和潜在的变革性的方法，将反应甲烷气体转化为高附加值的燃料和化学品。 更广泛的影响：高效NDMC膜反应器的发展可能会导致新的热化学过程，以满足高能量密度燃料的甲烷气体的需求。 该项目将沸石化学，固态离子，化学催化和分离过程的研究与教育和推广组成部分相结合，旨在突出与能源转换相关的化学工程的重要性。 教育将通过开发一个新的课程，根据PI在材料，催化，分离和能源的研究兴趣，通过招募和指导来自研究活动中代表性不足的社区的本科生，以及通过马里兰州大学附近的K-12学生的外展计划来加强。

1264599 LiuThe non-oxidative direct methane conversion (NDMC) to more valuable and easily transportable chemicals and fuels has remained a grand challenge due to the intrinsic kinetic and thermodynamic constraints. A recent report by the US Energy Information Administration envisions inexpensive and abundant natural gas as a raw material that can significantly impact the chemical and energy supplies of the world. A membrane reactor composed of a metal/zeolite (Mo/ZSM5) catalyst and a hydrogen (H2) permeable membrane has the potential to overcome these kinetic and thermodynamic barriers. The essential feature of the membrane reactor is that Mo species within spatially constrained ZSM5 channels containing Broensted acid sites activate methane to form carbon chains while concurrently restricting the carbon chain length; the H2 permeable membrane continuously removes H2 product to increase conversion relative to feed equilibrium limitations. The key objective of this research is to fabricate and describe novel tubular membrane reactors composed of ZSM5 lamellar catalysts and thin H2 permeable ceramic membranes. A focus of the research is controlling the ZSM5 crystal size by assembly of ZSM5 nanosheets and ceramic membranes to optimize methane (CH4) reaction kinetics and H2 separation in NDMC. Preliminary data show that activity of Mo/ZSM5 and H2 permeation through the ceramic membrane depends strongly on the ZSM5 crystal size and membrane thickness, respectively. A cross-disciplinary strategy will be used to control NDMC and create new and potentially transformative ways of converting reactant methane gas to high value-added fuels and chemicals. Broader Impacts: The development of efficient NDMC membrane reactors may lead to new thermochemical processes to meet the demand for high-energy density fuels from methane gas. The project integrates research on zeolite chemistry, solid state ioincs, chemical catalysis, and separation processes with an education and outreach component designed to highlight the importance of chemical engineering relevant to energy conversion. Education will be enhanced by developing a new course based upon PIs' research interests in materials, catalysis, separation, and energy, by recruiting and mentoring undergraduate students from underrepresented communities in research activities, and by outreach programs for K-12 students near the University of Maryland.