| dc.identifier.uri | http://hdl.handle.net/11401/77045 | |
| dc.description.sponsorship | This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree. | en_US |
| dc.format | Monograph | |
| dc.format.medium | Electronic Resource | en_US |
| dc.language.iso | en_US | |
| dc.publisher | The Graduate School, Stony Brook University: Stony Brook, NY. | |
| dc.type | Dissertation | |
| dcterms.abstract | Dependence on a finite supply of fossil fuel-based energy sources has provided motivation for research in and development of alternative, renewable energy sources. A strong candidate as an alternative fuel is ethanol. Ethanol has a high energy density, low toxicity, and as a liquid, compatibility with the existing fuel delivery infrastructure. When considering the possibility of using ethanol as a fuel, both synthetic methods to produce ethanol and reactions that convert ethanol to energy should be optimized. One method to produce ethanol is through the conversion of synthesis gas, or syngas, (CO + H2). Currently, syngas conversion is used to produce methanol, diesel and gasoline. Recent discoveries in catalyst design have shown that a series of RhFe/TiO2 and RhFe/CeO2 catalysts promote the formation of ethanol under CO hydrogenation conditions [1, 2]. Once ethanol is produced it needs to be converted into energy in an efficient method. One approach for ethanol conversion is through ethanol electro-oxidation. In this reaction, ethanol is oxidized into several products (acetic acid, acetaldehyde, CO, CO2), generating electrons. These electrons can be collected to make electricity. Platinum electrocatalysts are highly active for C-C bond scission, but are quickly poisoned by CO that is formed during oxidation. Another complication arising for Pt systems is the formation of partial oxidation products, which limit the overall efficiency. The addition of SnO2 nanoparticles to the Pt surface is known to improve current generation and the long-term stability of the Pt surface through a bifunctional mechanism in which SnO2 activates H2O to produce hydroxyls (-OH), which can be used to convert CO to CO2 [3, 4]. This work focuses on the development of new experimental methods, techniques and instrumentation to investigate reaction pathways and reaction intermediates occurring on the surface of these working catalysts. Custom designed reactor cells that can be used to mimic reaction conditions are coupled with Fourier transform infrared (FT-IR) spectroscopy to study how the additions of Fe to Rh/TiO2 and SnO2 to polycrystalline (pc)-Pt affect selectivity and reactivity. For SnO2/pc-Pt, the deposition of SnO2 nanoparticles directly onto the Pt surface via an ethylene glycol wet chemistry approach improves activity. The onset potential of EOR activity is negatively shifted by ~0.17V and there is 10-fold increase in current density, compared to pc-Pt alone. Infrared reflection absorption spectroscopy (IRRAS) measurements of the Pt surface under EOR conditions confirm the role of SnO2 as an aid to CO(ads)-Pt removal, which is evidenced by the complete removal of CO(ads) and the appearance of CO2 at more negative potentials. IRRAS measurements also show the SnO2/pc-Pt system promotes the formation of partial oxidation products, acetic acid and acetaldehyde. In situ transmission FT-IR experiments on a series of FeRh/TiO2 and FeRh/CeO2 catalysts for CO hydrogenation provide improved understanding as to how these catalysts function under reaction conditions. CO adsorption on Rh/TiO2 and Rh/CeO2 shows that the CeO2 support leads to an increased dispersion and smaller average particle size. The addition of Fe to these catalysts result in the appearance of a new CO band, likely due to CO adsorbed on Rh that is alloyed with Fe, confirming the presence of FeRh alloy at the surface of these catalysts. Comparing the transmission IR spectra under reaction conditions it becomes clear that Fe promotion improves ethanol selectivity by helping to deregulate CH4 formation by breaking up large extended Rh0 crystallites typically active for CO dissociation. | |
| dcterms.available | 2017-09-20T16:51:46Z | |
| dcterms.contributor | White, Michael G | en_US |
| dcterms.contributor | Khalifah, Peter | en_US |
| dcterms.contributor | Sears, Trevor | en_US |
| dcterms.contributor | Stacchiola, Dario J. | en_US |
| dcterms.creator | Magee, Joseph William | |
| dcterms.dateAccepted | 2017-09-20T16:51:46Z | |
| dcterms.dateSubmitted | 2017-09-20T16:51:46Z | |
| dcterms.description | Department of Chemistry | en_US |
| dcterms.extent | 113 pg. | en_US |
| dcterms.format | Application/PDF | en_US |
| dcterms.format | Monograph | |
| dcterms.identifier | http://hdl.handle.net/11401/77045 | |
| dcterms.issued | 2016-12-01 | |
| dcterms.language | en_US | |
| dcterms.provenance | Made available in DSpace on 2017-09-20T16:51:46Z (GMT). No. of bitstreams: 1
Magee_grad.sunysb_0771E_13015.pdf: 3404673 bytes, checksum: 738779539a22d0f1e0e4d43421e755aa (MD5)
Previous issue date: 1 | en |
| dcterms.publisher | The Graduate School, Stony Brook University: Stony Brook, NY. | |
| dcterms.subject | Chemistry | |
| dcterms.subject | Catalysis, Electrocatalysis, Ethanol, FTIR | |
| dcterms.title | Mechanistic Studies in Heterogeneous Catalysis via in situ FT-IR Spectroscopy | |
| dcterms.type | Dissertation | |
