Development and characterization of dispersed alkali carbonates as solid bases for C-H carboxylation reactions
Abstract/Contents
- Abstract
- Transitioning to a more sustainable chemical industry requires developing syntheses that minimize energy input and waste and can utilize waste materials such as carbon dioxide (CO2). A major contributor to the energy input of processes is the upstream energy required to synthesize any stoichiometric reagents used. Therefore, avoiding stoichiometric use of energy-intensive resources is imperative. One approach to CO2 utilization is the formation of carboxylic acids and derivatives, a valuable set of materials with applications in polymers, solvents, and fine chemicals. Synthesizing these from CO2 and un-activated C-H bonds would incorporate CO2 as a C1 feedstock and could displace conventional methods that rely on harsh oxidations. Due to the stability of the reactants, developing a process that avoids stoichiometric reagents that are energy-intensive to produce has been a continuing challenge. Prior work in the Kanan lab involved developing conditions for the C-H carboxylation of monocarboxylate salts (pKa > 35) to form the corresponding dicarboxylates, using carbonate as a base under high CO2 pressures. Carbonate is an attractive base because it can be easily regenerated from its conjugate acid, bicarbonate, by thermal decomposition. More recently, we have expanded the scope of this reaction to neutral substrates using a high surface area super basic carbonate formed by dispersing alkali carbonate salts into the pores of an inert mesoporous support. The carbonate can be regenerated after methylation and removal of the carboxylate product and used for multiple cycles. This dissertation will describe the early development of this reaction for arene esterification, further improvements in the carbonate base by moving to high pore volume mesoporous carbon supports, and efforts to better understand the carbonate structure and origin of the super-basicity at high temperatures. The first chapter will be a brief review of solid base chemistry the use of solid base catalysts in industrial setting. The second chapter will introduce the development of mesoporous dispersed carbonates and their application for a closed, two-step cycle for arene esterification with CO2 and methanol. The third chapter will describe how mesoporous carbon supports can be used to increase the reactive fraction of the material by increasing both the carbonate loading and conversion. The fourth and final chapter will describe studies to better understand the carbonate structure and origin of the super-basicity through high-temperature characterization by IR spectroscopy.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2022; ©2022 |
| Publication date | 2022; 2022 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Chant, Emma Dorothy |
|---|---|
| Degree supervisor | Kanan, Matthew William, 1978- |
| Thesis advisor | Kanan, Matthew William, 1978- |
| Thesis advisor | Solomon, Edward I |
| Thesis advisor | Xia, Yan, 1980- |
| Degree committee member | Solomon, Edward I |
| Degree committee member | Xia, Yan, 1980- |
| Associated with | Stanford University, Department of Chemistry |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Emma Chant. |
|---|---|
| Note | Submitted to the Department of Chemistry. |
| Thesis | Thesis Ph.D. Stanford University 2022. |
| Location | https://purl.stanford.edu/gb341qs4986 |
Access conditions
- Copyright
- © 2022 by Emma Dorothy Chant
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
Also listed in
Loading usage metrics...