미래창조과학부 글로벌프론티어 ( 재 ) 멀티스케일 에너지 시스템 연구단은 나노기술과 에너지 기술의 융합을 통하여 혁신적 미래 광에너지와 분자에너지 원천기술 개발을 목표로 하는 멀티스 케일 에너지 시스템 연구사업을 추진하고 있습니다. 연구단에서는 격주로 멀티스케일 에너지 강 좌를 개최합니다. 관심 있는 분들의 많은 참석 바랍니다. 1. 제 목 : Direct methane fueled solid oxide fuel cells using partial oxidation of methane 2. 연 사 : 문주호 교수 ( 연세대학교 신소재공학부 ) 3. 일 시 : 2013 년 06 월 24 일 ( 월 ) 오후 17:00 ~ 18:00 4. 장 소 : 서울대학교 신공학관 (301 동 ) 117 호 세미나실 5. 내 용 : 고체산화물 연료전지 (Solid oxide fuel cells) Abstract : Solid oxide fuel cells (SOFCs) are the most promising technologies for highly efficient and sustainable energy production. Unlike the proton exchange membrane fuel cells that require hydrogen fueling, because they are based on proton conducting electrolytes, SOFCs can oxidize essentially any fuel, from hydrogen to hydrocarbons to even carbon, because the electrolyte transports an oxygen ion. With the advantage of fuel flexibility, SOFCs have a practical potential in which the existing hydrocarbon fuel infrastructure is readily used. In this respect, there are lots of interests for SOFCs working with the direct fueling of methane. Here, we introduce the direct methane fueled SOFCs, relying on partial oxidation of methane on conventional Ni electrodes. It is demonstrated that a simple reformer-free SOFC system can be constructed by control of the anode microstructure without the poisoning of Ni electrodes by carbon coking, which is commonly observed when methane is fed to SOFCs directly. To elucidate the detailed mechanisms of chemical/electrochemical reactions on Ni catalysts, the oscillation phenomena during the partial oxidation was studied via a novel in situ electrochemical characterization. The results show that the oxidation of Ni, which could be induced by the oxygen gas during the partial oxidation, occurs dominantly and selectively on two phase boundaries (2PBs) of Ni and gas, while Ni at three phase boundaries (3PBs) remains as metallic state. Therefore, Ni oxidation during the partial oxidation of methane can be prevented by the increase of relative 3PBs ratio. And the direct methane fueled SOFCs using partial oxidation of methane are fabricated and characterized. The SOFCs using yttria-stabilized zirconia (YSZ) for high temperature applications showed the maximum power density at 800 o C (the same as the hydrogen fueling) with mixed gas condition of oxygen to methane ratio equals to 2 (CH 4 /O 2 =2), which is the stoichiometric composition of partial oxidation of methane. Also the SOFCs using gadolia-doped ceria (GDC) for low temperature SOFCs exhibited the maximum power density at 650 o C under the mixed gas condition. Stable operation of 50 hours was achieved under the mixed gas condition, confirming that there was no carbon coking, and the decrease of polarization resistance was observed when it was compared with the operation under the pure methane, which indicates the enhanced kinetics of methane cracking by the oxygen. 6. 약 력 : 학력사항 연세대학교 세라믹공학과 학사 Univ. of Florida 재료공학과 석사 Univ. of Florida 재료공학과 박사 경력사항 M.I.T 재료 공정 센터 / Research Associate 일본 통상성 산업기술연구원 (AIST) / 초빙연구원 연세대학교 신소재공학부 / 조교수 연세대학교 신소재공학부 / 부교수 미국 Univ. of Washington / 방문교수 현재 연세대학교 신소재공학부 / 정교수  문 의 : 멀티스케일 에너지 시스템 연구단 연구지원본부 ( ☏ ,6670) 남기태 교수 ( 재료공학부 ), 최만수 교수 ( 기계항공공학부 ) 미래창조과학부 글로벌 프론티어 멀티스케일 에너지 시스템 연구단 / 서울대학교 멀티스케일 에너지 강좌