Studies of Carbon Dioxide Reduction on Cu/Au Ultrasmall Nanoparticles.
- Resource Type
- Theses
- Authors
- Shang, Hongyu
- Source
- Dissertations Abstracts International; Dissertation Abstract International; 84-01B.
- Subject
- Chemistry
Nanoscience
Carbon dioxide reduction
Nanoparticles
Electrocatalysis
- Language
- English
Summary: Carbon dioxide reduction (CO2R) is important because CO2 represents a renewable feed stock for chemical synthesis and alternative fuels. Conversion of atmospheric CO2 by CO2R is also important for environmental remediation. Nanoparticle catalysts are efficient due to their high surface to volume ratio and controllable structure and size. Herein I investigate carbon dioxide reduction using ultrasmall Cu/Au nanoparticles. The effect of surface ligands is demonstrated. Results show that dodecanethiol on Au nanoparticles largely improves selectivity and stability by preventing ion deposition on a Au surface without blocking transport of CO2, and this effect is both ligand identity and structure dependent. I also examine this protecting effect in ambient river water prepared electrolyte and find that Au nanoparticles show more than 100 times higher CO yield compared to polycrystalline Au under the same potential. Such results provide a new solution to expensive electrolyte purification problem, which plays an important role in electrocatalysis. These ultrasmall nanoparticles also provide the opportunity to study the ensemble effect due to their unfavorable core-shell structure. I find that Cu2 ensembles influence the formation pathway of C1 products between CO and HCOOH. Such results provide opportunity to tailor the catalytic performance by modifying the catalyst surface with different ensembles to tune the catalytic activity and selectivity.