온도와 전구체 조건에 따라서 달라지는 흑연화 정도에 의한 비귀금속계 촉매의 알칼리 조건에서의 산소환원반응의 활성

Abstract

Over the decades, various catalysts have been investigated to replace the state-of-the-art Pt catalyst for oxygen reduction reaction (ORR), because the cost of Pt catalysts accounts for more than 50% of a fuel cell stack cost when the fuel cell electric vehicles are produced for 500,000 units per year. Thus, economic catalysts such as Fe-N/C as non-precious metal catalyst are the final goal of catalyst research and development. In this study, we use several temperature conditions, such as 1000°C, 900°C and 800°C with 1:2 and 1:4 of iron and nitrogen atomic ratios in the precursor solution to investigate the dominant effects towards ORR activity in alkaline condition. At temperatures above 900°C, a sharp peak is observed at 26° position in the wide-angle XRD pattern, which means graphitic order increase because the position is general graphite carbon peak for (002) plane. Using Mering-Merire index, we find that 1:2 atomic ratios shows better graphitic order than 1:4 atomic ratios. Also, the products appear better ORR activity. Thus, the products are analyzed by X-ray photoelectron spectroscopy(XPS), N2 sorption, X-ray diffraction (XRD) and electrochemical technics to investigate the reasons.