Full metadata record
| DC Field | Value | Language |
|---|---|---|
| dc.contributor.advisor | Shanmugam, Sangaraju | - |
| dc.contributor.author | Jo, Ga Young | - |
| dc.date.accessioned | 2017-05-10T08:50:00Z | - |
| dc.date.available | 2016-05-18T00:00:00Z | - |
| dc.date.issued | 2013 | - |
| dc.identifier.uri | http://dgist.dcollection.net/jsp/common/DcLoOrgPer.jsp?sItemId=000002262499 | en_US |
| dc.identifier.uri | http://hdl.handle.net/20.500.11750/1333 | - |
| dc.description.abstract | A facile and cost-effective single-step pyrolysis approach using a single precursor is introduced to fabricate boron-doped carbons (BDC700 and BDC900) and phosphorus or boron selective-doped-graphenes (PDG700 and BDG900) without using a template, solvent, or catalyst. By increasing the temperature from 700 °C to 900 °C, the tuning of the boron doping level was found in BDCs, and tuning of doping level and selection of heteroatom were possible in PDG700 and BDG900. BDC900, PDG700, and BDG900 were found to have the ability to reduce oxygen directly to water with a four-electron oxygen reduction pathway in an alkaline medium. All four catalysts exhibited excellent stability and resistance to methanol oxidation and CO poisoning. BDCs, PDG700, and BDG900 are a promising alternative to conventional Pt-based catalysts as metal-free catalysts for oxygen reduction reaction in alkaline fuel cells. ⓒ 2013 DGIST | - |
| dc.description.tableofcontents | I. Introduction 1 -- 1.1 Motivation 1 -- 1.2 Objectives 3 -- II. Theoretical background 4 -- 2.1 Fuel cells 4 -- 2.1.1 Fuel cell fundamentals 4 -- 2.1.2 Oxygen reduction reaction (ORR) 12 -- 2.2 Heteroatom-doped carbon 16 -- 2.2.1 Properties 16 -- 2.2.2 Synthetic approaches 20 -- 2.3 Graphene 22 -- 2.3.1 Properties 23 -- 2.3.2 Applications 25 -- III. Experimental 26 -- 3.1 Preparation of electrocatalysts 26 -- 3.1.1 Boron-doped carbon and their references 26 -- 3.1.2 Phosphorus or boron-selective-doped graphene and their references 26 -- 3.2 Characterization 30 -- 3.2.1 Thermo-gravimetric analysis (TGA) 30 -- 3.2.2 Electron microscope study 30 -- 3.2.3 X-ray diffraction (XRD) study 30 -- 3.2.4 Raman spectroscopic study 31 -- 3.2.6 Electrochemical study 31 -- 3.2.7 Selectivity study: methanol oxidation tolerance and CO poisoning test 33 -- 3.2.8 Durability test 35 -- IV. Results and discussion 37 -- 4.1 Boron-doped carbon 37 -- 4.1.1 Thermo-gravimetric analysis (TGA) 37 -- 4.1.2 Electron microscope study 39 -- 4.1.3 X-ray diffraction (XRD) study 42 -- 4.1.4 Raman spectroscopic study 43 -- 4.1.5 X-ray photoelectron spectroscopic (XPS) study 45 -- 4.1.6 Electrochemical study 48 -- 4.1.7 Selectivity and durability study 54 -- 4.2 Phosphorus or boron-selective-doped graphene 57 -- 4.2.1 Thermo-gravimetric analysis (TGA) 57 -- 4.2.2 Electron microscope study 59 -- 4.2.3 X-ray diffraction (XRD) study 62 -- 4.2.4 Raman spectroscopic study 64 -- 4.2.5 X-ray photoelectron spectroscopic (XPS) study 66 -- 4.2.6 Electrochemical study 70 -- 4.2.7 Selectivity and durability study 75 -- V. Conclusion 78 -- References 79 -- 요약문 87 |
- |
| dc.format.extent | 87 | - |
| dc.language | eng | - |
| dc.publisher | DGIST | - |
| dc.subject | Heteroatom-doped carbon | - |
| dc.subject | Electrocatalyst | - |
| dc.subject | Oxygen reduction | - |
| dc.subject | Alkaline fuel cells | - |
| dc.subject | Non-precious catalyst | - |
| dc.subject | 이종 원소 도핑 탄소 | - |
| dc.subject | 전기화학적 촉매 | - |
| dc.subject | 산소환원반응 | - |
| dc.subject | 알카라인 연료전지 | - |
| dc.subject | 비백금 촉매 | - |
| dc.title | Heteroatom-Doped Carbon as a Non-precious Catalyst for Oxygen Reduction Reactionin Alkaline Medium | - |
| dc.title.alternative | 이종 원소가 도핑된 탄소재료를 이용한 알카라인 연료전지 Cathode 용 산소환원 촉매의 합성 및 평가 | - |
| dc.type | Thesis | - |
| dc.identifier.doi | 10.22677/thesis.2262499 | - |
| dc.description.alternativeAbstract | 알카라인 연료전지에서 산소환원반응이 일어나는 cathode의 백금촉매를 대체하여 연료전지 제작 비용 감소에 기여하고자 비백금 촉매를 합성하였다. 촉매의 합성에 이용된 solid-state pyrolysis 은 단일 전구체로부터 단일 process를 거쳐 탄소격자 내에 이종 원소를 치환도핑하는 손 쉬운 기술이다. 또한 별도의 templates, solvents, catalysts가 필요하지 않으며, 대량생산에도 용이하게 적용될 수 있다는 점에서 이용가치가 있다. Tetraphenylboron sodium으로부터 boron-doped carbons (BDC700와 BDC900) 을, tetraphenylphosphonium tetraphenylborate 와 graphene이 혼합된 전구체로부터 phosphorus-doped graphene (PDG700) 와 boron-doped-graphene (BDG900) 을 각각 합성하였다. Solid-state pyrolysis는 700 °C 와 900 °C 에서 각각 진행되었는데, 온도의 조절은 재료의 물성에 변화를 주었다. BDC합성의 경우, boron 도핑 레벨이 변하였으며, PDG700와 BDG900합성의 경우에는 도핑된 이종 원소의 종류가 조절되었다. 전기화학적 특성평가로부터, BDC900 과PDG700 및 BDG900 은 알카라인 전해질에서 백금과 같이4 전자 산소환원반응을 촉진하며 commercial 백금촉매와 견줄 수 있는 산소환원능력을 가짐을 알게 되었다. 지속적인 산소환원반응 하에서의 내구성과, 메탄올 crossover 및 CO 피독작용에 대한 저항성은 백금촉매를 압도하였다. 이러한 결과는, 기존의 백금촉매를 대체하여 연료전지 전체 제작비용을 감소시킴으로써, 연료전지의 상업화에 기여할 가능성을 제시한다. 또한 탄소격자 내 이종 원소 도핑 및 solid-state pyrolysis 기술은 광범위한 촉매 분야로의 무한한 적용가능성을 시사한다. ⓒ 2013 DGIST | - |
| dc.description.degree | Master | - |
| dc.contributor.department | Energy Systems Engineering | - |
| dc.contributor.coadvisor | Kim, Soon Hyun | - |
| dc.date.awarded | 2013. 2 | - |
| dc.publisher.location | Daegu | - |
| dc.description.database | dCollection | - |
| dc.date.accepted | 2016-05-18 | - |
| dc.contributor.alternativeDepartment | 대학원 에너지시스템공학전공 | - |
| dc.contributor.affiliatedAuthor | Jo, Ga Young | - |
| dc.contributor.affiliatedAuthor | Shanmugam, Sangaraju | - |
| dc.contributor.affiliatedAuthor | Kim, Soon Hyun | - |
| dc.contributor.alternativeName | 조가영 | - |
| dc.contributor.alternativeName | 상가라쥬샨무감 | - |
| dc.contributor.alternativeName | 김순현 | - |
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