Full metadata record
DC Field | Value | Language |
---|---|---|
dc.contributor.advisor | Han, Byung Chan | - |
dc.contributor.author | Kwak, Do Hyun | - |
dc.date.accessioned | 2017-05-10T08:50:55Z | - |
dc.date.available | 2015-01-12T00:00:00Z | - |
dc.date.issued | 2015 | - |
dc.identifier.uri | http://dgist.dcollection.net/jsp/common/DcLoOrgPer.jsp?sItemId=000001923020 | en_US |
dc.identifier.uri | http://hdl.handle.net/20.500.11750/1374 | - |
dc.description.abstract | First principles density functional theory calculations are utilized to unveil oxygen reduction reaction mechanisms on nitrogen doped graphene (N-Gr). Considering the effect of both the geometry and concentration of N in bulk and edge N-Gr forms, we calculate the energies of a large number of model systems to cover a wide range of possible N-Gr structures and determine the most stable ones. In agreement with experiments, our calculations suggest that doping levels in stable N-Gr forms are limited to less than about 30 at.%, above which the hexagonal graphene framework is broken. Remarkably, the ground state structures of bulk and edge N-Gr are found to differ depending on the doping level and poisoning of the edge bonds. ORR mechanisms are estimated using Gibbs free energy diagrams, both with and without water solvation. Our results indicate that N doping significantly alters the catalytic properties of pure graphene and that dilutely doped bulk N-Gr forms are the most active. ⓒ 2015 DGIST | - |
dc.description.tableofcontents | 1. Introduction 1-- 1.1. Introduction to First principles DFT calculations 1-- 1.2. Background 1-- 2. Methodology and Model Systems 3-- 2.1. Computational Details 3-- 2.2. DFT calculations of stable N-Gr Structures 4-- 2.3. Poisoning of dangling bonds in edge N-Gr 6-- 3. Results and Discussion 11-- 3.1. Electronic structures of N-Gr model systems 11-- 3.2. Thermodynamic free energy diagram of ORR: Formalism 12-- 3.3. Gibbs free energy diagrams for ORR: The effect of dopant concentration 13-- 3.4. Thermodynamic free energy diagram of ORR: Effect of water solvation 18-- 4. Conclusion 20-- References 21-- Summary(국문요약) 25-- Acknowledgement 26-- Curriculum Vitae 27 |
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dc.format.extent | 28 | - |
dc.language | eng | - |
dc.publisher | DGIST | - |
dc.subject | First principles | - |
dc.subject | Renewable energy | - |
dc.subject | Graphene | - |
dc.subject | Catalyst | - |
dc.subject | Oxygen reduction reaction | - |
dc.subject | 제 일 원리 | - |
dc.subject | 신 재생에너지 | - |
dc.subject | 그래핀 | - |
dc.subject | 촉매 | - |
dc.subject | 산소환원반응 | - |
dc.title | First Principles Study of Morphology, Doping Level and Water Solvation Effects on Catalytic Mechanism of a Graphene Towards Oxygen Reduction Reaction | - |
dc.title.alternative | 제 1 원리 전산을 이용하여 모폴로지, 도핑농도, 용매가 그래핀에서 산소환원반응에 미치는 영향 분석 | - |
dc.type | Thesis | - |
dc.identifier.doi | 10.22677/thesis.1923020 | - |
dc.description.alternativeAbstract | 연료전지는 에너지 생산문제를 해결할 수 있는 유망한 신 재생에너지원으로 조명되고 있지만, 비싼 백금촉매가격 및 상용화에는 부족한 내구성과 촉매활성 문제로 어려움을 겪고 있다. 최근, 백금촉매를 대체할 수 있는 비 백금 촉매를 개발하기 위한 연구가 진행되고 있다. 비 백금촉매 중에서 질소도핑 그래핀(N-Gr)은 백금촉매와 비슷한 산소환원반응(ORR) 촉매활성이 보고되었다. 그러나, 산소환원반응에 기여하는 N-Gr의 구체적인 구조는 밝혀지지 않았고 N-Gr에서의 산소환원반응 메커니즘에 대해서도 많은 연구가 필요하다. ⓒ 2015 DGIST | - |
dc.description.degree | Master | - |
dc.contributor.department | Energy Systems Engineering | - |
dc.contributor.coadvisor | Yoon, Young Gi | - |
dc.date.awarded | 2015. 2 | - |
dc.publisher.location | Daegu | - |
dc.description.database | dCollection | - |
dc.date.accepted | 2015-01-12 | - |
dc.contributor.alternativeDepartment | 대학원 에너지시스템공학전공 | - |
dc.contributor.affiliatedAuthor | Kwak, Do Hyun | - |
dc.contributor.affiliatedAuthor | Han, Byung Chan | - |
dc.contributor.alternativeName | 곽도현 | - |
dc.contributor.alternativeName | 한병찬 | - |
dc.contributor.alternativeName | 윤영기 | - |