Collaborative Research: Advanced Zeolite-Composite Adsorbents with Fine-Tuned Pore Sizes for Molecular Sieving Separations

合作研究：用于分子筛分离的具有微调孔径的先进沸石复合吸附剂

• 批准号: 1402772
• 负责人: Miao Yu
• 金额: $ 22.78万
• 依托单位: University of South Carolina at Columbia
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1402772&HistoricalAwards=false
• 关键词: Collaborative; Research; Advanced; Zeolite; Composite

PI: Yu, Miao / Liang, XinhuaProposal Number: 1402772 / 1402122Title: Collaborative Research: Advanced Zeolite-Composite Adsorbents with Fine-Tuned Pore Sizes for Molecular Sieving Separations Mixture separation constitutes a large and costly component of industrial processes. Various separation technologies, such as distillation, extraction, adsorption, and membrane separation, have been developed to separate mixtures utilizing different properties of components in the mixture. Among these technologies, separation processes based on adsorption, such as pressure swing adsorption (PSA) and temperature swing adsorption (TSA), have been widely used in industry. Development of more energy-efficient adsorptive gas separation processes strongly depends on the development of improved porous adsorbents, and porous adsorbents with favorable adsorption isotherms and selectivity for the separation of interest are always the focus of adsorption-based separation processes. Zeolites are one of the most promising adsorbents that may realize true molecular-sieving separation under harsh separation conditions, attributing to their uniform, molecular-sized pores and high chemical, thermal and mechanical stabilities. Despite of a large selection pool of zeolites/molecular sieves and available techniques to adjust their pore sizes, not all desired pore sizes can be obtained for target separations, especially for separation of molecules with very close sizes, such as N2 (kinetic diameter: 0.364 nm)/CH4 (0.38 nm), O2 (0.346 nm)/N2, and paraffin/olefin. Therefore, it is highly desirable to develop new strategies to further fine-tune the pore sizes of zeolite-based materials and fill the pore size gaps between different zeolites. The goal of this proposed research is to fine-tune the pore entrance of zeolites by depositing ultrathin microporous coatings to achieve effective separation for industrially important mixtures that traditional zeolites have difficulty to separate. Ultrathin microporous coatings will be deposited using molecular layer deposition (MLD) on the zeolites to fill the pore-size gaps between different zeolites an obtain enhanced fundamental understanding of deposition mechanisms and coating interactions with zeolite substrates. Specifically, the objectives of the proposed research are: (1) To develop a reliable and reproducible MLD process to deposit ultrathin organic/inorganic hybrid films (with precisely controlled properties) on zeolite substrates and obtain a fundamental understanding on the factors that affect the quality of MLD coatings; (2) To elucidate and understand the decomposition of hybrid MLD coating and pore-generation mechanisms under different conditions; (3) To characterize effective pore sizes of zeolite-composite adsorbents and establish the fundamental coating property-pore entrance size relationship; and (4) To rationally design zeolite composite adsorbents with desired pore sizes and investigate separation performance for target mixtures. This completely new concept may lead to effective adsorptive separation of difficult-to-separate mixtures.This proposed research is expected to have great scientific as well as technological impact on the synthesis of nanostructured zeolite-composite adsorbents with fine-tuned pore sizes for mixture separations and potentially for selective catalysis. If successful, the project will greatly benefit adsorption-based separation processes. It will represent a significant advance in the rational design of zeolite-based adsorbents. The proposed research has significant practical implications on industrially important gas mixture separations. It is anticipated that this study could serve as a model for the rational design of advanced sorbents for adsorption-based separation processes.The PIs have specific defined plans to engage a broad range of students in learning about nanomaterials and molecular sieves. Specific opportunities for minorities will be funded through targeted scholarships and projects during the summer. Both PIs are active in outreach programs for K-12 students in mainly underrepresented populations in the areas of both universities.

主要研究者：余淼/梁新华提案号：1402772 /1402122题目：合作研究：用于分子筛分离的具有精细调节孔径的高级沸石复合吸附剂混合物分离构成工业过程的大而昂贵的组成部分。已经开发了各种分离技术，例如蒸馏、萃取、吸附和膜分离，以利用混合物中组分的不同性质来分离混合物。在这些技术中，基于吸附的分离方法，例如变压吸附（PSA）和变温吸附（TSA），已经在工业中广泛使用。高效吸附气体分离技术的发展在很大程度上依赖于多孔吸附剂的开发，具有良好吸附等温线和选择性的多孔吸附剂一直是吸附分离技术的研究热点。沸石分子筛具有均匀的分子大小的孔结构和较高的化学、热、机械稳定性，是在苛刻的分离条件下实现真正分子筛分离的最有前途的吸附剂之一。尽管有大量的沸石/分子筛选择池和调节其孔径的可用技术，但对于目标分离，特别是对于分离具有非常接近的尺寸的分子，例如N2（动力学直径：0.364 nm）/CH 4（0.38 nm）、O2（0.346 nm）/N2和链烷烃/烯烃，并不能获得所有期望的孔径。因此，非常需要开发新的策略来进一步微调沸石基材料的孔径并填充不同沸石之间的孔径间隙。 本研究的目的是通过沉积纳米微孔涂层来微调沸石的孔入口，以实现传统沸石难以分离的工业重要混合物的有效分离。将使用分子层沉积（MLD）在沸石上沉积超薄微孔涂层，以填充不同沸石之间的孔径间隙，并获得对沉积机制和涂层与沸石基底的相互作用的增强的基本理解。具体而言，本研究的目标是：（1）发展一种可靠的、可重复的MLD工艺来制备存款有机/无机杂化薄膜（2）阐明和理解混合MLD涂层在不同条件下的分解和孔生成机理;（3）表征沸石复合吸附剂的有效孔径，建立基本的涂层性能-孔径关系;（4）合理设计具有理想孔径的沸石复合吸附剂，考察其对目标混合物的分离性能。这一全新的概念可能会导致难以分离的混合物的有效吸附分离，这项拟议的研究预计将有很大的科学和技术的影响，纳米结构的沸石复合吸附剂的合成与微调孔径的混合物分离和潜在的选择性催化。如果成功，该项目将大大有利于基于吸附的分离工艺。这将代表沸石基吸附剂的合理设计的一个重大进展。该研究对工业上重要的气体混合物分离具有重要的实际意义。预计这项研究可以作为一个模型，为先进的吸附剂的合理设计为基础的吸附分离processes.The PI有具体的定义的计划，从事广泛的学生在学习纳米材料和分子筛。在夏季，将通过有针对性的奖学金和项目为少数民族提供具体机会。这两个PI都积极参与K-12学生的外展计划，这些学生主要是两所大学所在地区代表性不足的人群。