Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2008. / Includes bibliographical references (p. 154-165). / To facilitate commercialization of fuel cell systems as alternative energy device, the enhancement of Pt electrocatalysts activity is one of the most challenging issues. The first step to the solution is elucidating relationship between surface structure and chemical reactivity as electrocatalysis occurs on its surface. However, in spite of concerted experimental and theoretical research over the last decades, the detailed mechanism is still in debate. This thesis explores a structural sensitivity of the chemical reactivity in the Pt-based alloy electrocatalysts by combining ab-initio density functional theory (DFT) with relevant thermodynamic and kinetic approach. We developed a rigorous statistical mechanical formalism, which can parameterize the energetics obtained by first principles calculations as a function of surface topologies. This methodology enables kinetic Monte Carlo simulations to provide thermally equilibrated structures as a function of partial pressures of adsorbates and alloy compositions. With our consistent methods, we characterize surface structures on the atomic scale, and quantify chemical reactivity of various Pt-alloy model systems. Our methodology reproduced accurate and consistent results of available experimental measurements. We find that our methodology is considerably useful for studying the structural effect on the heterogeneous catalysis. Through the thesis, we understood better how surface structures evolve according to environmental conditions and hence, the structure-activity relationship, which is useful for design of electrocatalysts. / by Byungchan Han. / Ph.D.
| Identifer | oai:union.ndltd.org:MIT/oai:dspace.mit.edu:1721.1/44313 |
| Date | January 2008 |
| Creators | Han, Byungchan |
| Contributors | Gerbrand Ceder., Massachusetts Institute of Technology. Dept. of Materials Science and Engineering., Massachusetts Institute of Technology. Dept. of Materials Science and Engineering. |
| Publisher | Massachusetts Institute of Technology |
| Source Sets | M.I.T. Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | 165 p., application/pdf |
| Rights | M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission., http://dspace.mit.edu/handle/1721.1/7582 |
Page generated in 0.0017 seconds