Hierarchical metal-organic frameworks and membranes for energy-related separations
Open Access
- Author:
- Yin, Xinyang
- Graduate Program:
- Chemical Engineering
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- September 27, 2021
- Committee Members:
- Xueyi Zhang, Chair & Dissertation Advisor
Jian Yang, Outside Unit & Field Member
Darrell Velegol, Major Field Member
Seong Han Kim, Professor in Charge/Director of Graduate Studies
Hee Jeung Oh, Major Field Member
Jian Yang, Outside Unit & Field Member - Keywords:
- Hierarchical MOF
MOF
morphology control
gas separation
liquid separation
pore environment - Abstract:
- Separation process is considered as an important step in the production of industrial chemicals. During the essential separation processes, raw materials contaminants are removed, primary products are purified, recovered and recycled, the pollutants from effluents are collected for further elimination process. Metal-Organic Framework (MOF) is a promising porous material which can improve separation performance and save energy consumed. The performance in the following highlighted fields is not yet satisfactory with MOFs: hydrocarbon from crude oil, alkenes from alkanes, and trace contaminants from water by adsorption or membrane filtration. We propose that hierarchical MOFs and MOF composites can overcome the current limits. We demonstrate heterometallic hierarchical MOF nanoparticles formed by intergrowth of pillared MOFs. The hierarchical MOFs have shown increased adsorption of hydrocarbons at low pressures, and IAST selectivity of propane/methane as high as 53 were observed (total pressure 1 bar, CH4 mole fraction: 0.8), suggesting the hierarchical materials can be used for adsorptive removal of natural gas liquids (C2, C3 and C4 hydrocarbons) from crude natural gas. We attach finned hierarchical MOF particles (Cu(BDC) as fins grown perpendicularly on Ni2(BDC)2(DABCO) hexagonal prisms) on modified cellulose support. The hierarchical MOF particles preserved the mesopores and exposed the open Cu(II) sites on Cu(BDC) to enable selective 1-hexene/n-hexane separation (ideal selectivity = 11.4). We report an oriented continuous 2-D MOF Cu(BDC) coating on bacteria cellulose (BC) for removing nitrobenzene from water. The Cu(BDC) supported on BC hierarchical composite reported in this work shows high water permeance (10.85 L/(hr·m2·psi) and high rejection of nitrobenzene (68.6%), which are higher than state-of-the-art polymeric membranes. These hierarchical MOFs and composites have demonstrated their outstanding ability for separation in various applications and motivated for further research.