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.

首席研究员：于苗/梁新华 提案编号：1402772 / 1402122 标题：合作研究：用于分子筛分离的先进沸石复合吸附剂，其孔径可微调 混合物分离是工业过程中一个庞大且昂贵的组成部分。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。其中，基于吸附的分离工艺，如变压吸附（PSA）和变温吸附（TSA）已在工业中得到广泛应用。更节能的吸附气体分离过程的开发很大程度上取决于改进的多孔吸附剂的开发，而具有良好的吸附等温线和目标分离选择性的多孔吸附剂始终是基于吸附的分离过程的焦点。沸石是最有前途的吸附剂之一，可以在恶劣的分离条件下实现真正的分子筛分分离，这归因于其均匀的分子大小的孔以及高化学、热和机械稳定性。尽管有大量的沸石/分子筛可供选择，并且有可用的技术来调整其孔径，但并非可以获得目标分离所需的所有孔径，特别是对于尺寸非常接近的分子的分离，例如 N2（动力学直径：0.364） nm)/CH4 (0.38 nm)、O2 (0.346 nm)/N2 和石蜡/烯烃。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补不同沸石之间的孔径差距。 这项研究的目标是通过沉积超薄微孔涂层来微调沸石的孔隙入口，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，从而增强对沉积机制以及涂层与沸石基材相互作用的基本了解。具体来说，本研究的目标是：（1）开发一种可靠且可重复的MLD工艺，在沸石基底上沉积超薄有机/无机杂化薄膜（具有精确控制的性能），并对影响质量的因素有一个基本的了解。 MLD 涂层； (2) 阐明和理解混合MLD涂层在不同条件下的分解和孔隙生成机制； (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)合理设计具有所需孔径的沸石复合吸附剂并研究目标混合物的分离性能。这个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。这项研究预计将对用于混合物分离的具有微调孔径的纳米结构沸石复合吸附剂的合成产生巨大的科学和技术影响并有可能用于选择性催化。如果成功，该项目将大大有利于基于吸附的分离工艺。它将代表沸石吸附剂合理设计的重大进步。所提出的研究对工业上重要的气体混合物分离具有重大的实际意义。预计这项研究可以作为基于吸附的分离过程的先进吸附剂的合理设计的模型。PI 制定了具体的计划，以吸引广大学生学习纳米材料和分子筛。夏季期间将通过有针对性的奖学金和项目为少数族裔提供特定机会。两位 PI 都积极参与面向 K-12 学生的外展项目，这些学生主要针对两所大学所在地区的代表性不足的人群。