1. Fuel Cell Laboratory, Korea Institute of Energy Research (KIER), 152, Gajeong, Yuseong, Daejeon 34129, South Korea
2. Renewable Energy Engineering, University of Science & Technology (UST), 217, Gajeong, Yuseong, Daejeon 34113, South Korea
3. Kolon Central Research Park, Kolon Industries, Inc., 154, Mabuk-ro, Yongin-Si, Gyeonggi-Do 16910, South Korea