Dissertation
Carboxylate-Based Metal-Organic Frameworks: Synthesis, Thermodynamic Analysis, and Catalytic Activity
Washington State University
Doctor of Philosophy (PhD), Washington State University
2023
DOI:
https://doi.org/10.7273/000005181
Abstract
Metal–organic frameworks (MOFs) are a uique class of coordination polymers consist of inorganic metal ions or clusters, known as secondary building units (SBUs), interconnected by organic linkers. Their remarkable properties, such as large surface areas, high porosities, high adaptability, and diverse functionalities, have made them popular and enabled their potential applications across many fields. Over the last three decades, more than 90,000 MOFs have been created. The preparation methods of MOFs evolved from the initial stages of simply obtaining the material to realizations of more sustainable syntheses. However, obtaining phase-pure products remains a challenge.. In this work, we developed a green, solvent-free synthetic method for the aluminum trimesates (Al-BTCs) system, which produces three distinct phases—MIL-96, MIL-100, and MIL-110—from the same metal and ligand precursors. However, obtaining pure-phase products remains challenging. We conducted a series of experiments to investigate the formation of Al-BTCs from an energetic perspective, finding that linker stabilization of the Al-polyhedra is crucial in the formation of the Al-BTC frameworks. Additionally, higher coordinative metal-polyhedra possess more enthalpic stabilization from the coordinated ligands.
We selected the solvent-free synthesized MIL-96(Al) as a support for Mn2+ dopants, creating an affordable catalyst, namely Mn(Ⅱ)@MIL-96(Al). We evaluated the catalytic value of Mn(Ⅱ)@MIL-96(Al) using the aerobic olefin epoxidation reaction under mild conditions, and the results demonstrated high efficiency and selectivity toward epoxide production.
Finally, we utilized an up-scaling, modulator-free synthetic approach to produce functionalized hierarchically porous UiO-66 (HP-UiO-66) materials. The defect sites, mesopores, and varying ratios of mixed ligands were introduced to enhance the catalytic activity of HP-UiO-66s. To evaluate the catalytic performance of the seven X:Y-HP-UiO-66 (X:Y = molar ratio of NH2BDC:BDC) derivatives with different Lewis acid-base functionalities, we employed CO2 cycloaddition with organic epoxide as a model reaction. The results demonstrated excellent catalytic performance, offering valuable insight for the rational design of MOFs via fine-tuning functionality for more efficient catalytic applications.
Metrics
118 File views/ downloads
47 Record Views
Details
- Title
- Carboxylate-Based Metal-Organic Frameworks
- Creators
- Jiahong Li
- Contributors
- Qiang Zhang (Advisor)Xiaofeng Guo (Committee Member)Ursula Mazur (Committee Member)Choong-Shik Yoo (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Chemistry, Department of
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 221
- Identifiers
- 99901019233001842
- Language
- English
- Resource Type
- Dissertation