Kyushu University · 에너지
Junji Nakamura 교수의 연구실은 전기화학적 에너지 변환 및 저장 기술을 위한 고성능 촉매 개발에 초점을 맞추고 있습니다. 주로 산소 분해 반응(ORR)과 이산화탄소 환원 반응에서의 촉매 활성 부위 규명, 특히 질소 도핑된 탄소 소재와 금속-산화물 계면에서의 반응 메커니즘을 연구합니다. 고해상도 표면 분석 및 고압 반응 측정 기법을 융합한 정밀한 반응성 분석을 통해 나노구조 촉매의 기초 원리를 규명하고 있습니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Nitrogen (N)-doped carbon materials exhibit high electrocatalytic activity for the oxygen reduction reaction (ORR), which is essential for several renewable energy systems. However, the ORR active site (or sites) is unclear, which retards further developments of high-performance catalysts. Here, we characterized the ORR active site by using newly designed graphite (highly oriented pyrolitic graphite) model catalysts with well-defined π conjugation and well-controlled doping of N species. The ORR
The oxygen reduction reaction (ORR) is a core reaction for electrochemical energy technologies such as fuel cells and metal-air batteries. ORR catalysts have been limited to platinum, which meets the requirements of high activity and durability. Over the last few decades, a variety of materials have been tested as non-Pt catalysts, from metal-organic complex molecules to metal-free catalysts. In particular, nitrogen-doped graphitic carbon materials, including N-doped graphene and N-doped carbon
The 12 wt% Pt-deposited carbon nanotube electrode gives 10% higher voltages than 29 wt% Pt-deposited carbon black and reduces the Pt usage by 60% in polymer electrolyte fuel cells with hydrogen and oxygen.
The structural sensitivity of the water-gas shift (WGS) reaction (CO + H2O → H2+ CO2) over metallic copper is addressed here by comparing its kinetics over the atomically clean Cu(110) surface with prior results for Cu(111). The surfaces were prepared and characterized with UHV surface analysis (AES, LEED, XPS), then transferred to an attached microreactor for medium-pressure [10–1000 Torr (1 Torr = 101 325/760 Pa)] kinetic measurements and finally returned to UHV for post-reaction surface analy
Kattel <i>et al</i> (Reports, 24 March 2017, p. 1296) report that a zinc on copper (Zn/Cu) surface undergoes oxidation to zinc oxide/copper (ZnO/Cu) during carbon dioxide (CO<sub>2</sub>) hydrogenation to methanol and conclude that the Cu-ZnO interface is the active site for methanol synthesis. Similar experiments conducted two decades ago by Fujitani and Nakamura <i>et al</i> demonstrated that Zn is attached to formate rather than being fully oxidized.
The interactions of CO2 with a clean Cu(110) surface have been studied both in an ultrahigh-vacuum surface analytical chamber and in an attached, high-pressure cell. No adsorption or dissociation of CO2 was measured for exposures up to 350 L at 110 K and 250 K. Exposures of 65 to 650 Torr of CO2 at 400-600 K led to the build-up of atomically adsorbed oxygen according to the reaction CO2.g to COg+Oa at a rate which increased with temperature ( approximately 16 kcal mol-1) and decreased with react
