1. Department of Energy Technology, Royal Institute of Technology (KTH), Stockholm 10044, Sweden; Department of Physics, COMSATS Institute of Information Technology, Lahore 54000, Pakistan
2. Department of Energy Technology, Royal Institute of Technology (KTH), Stockholm 10044, Sweden; GETT Fuel Cell AB, Stora Nygatan 33, Stockholm S-10314, Sweden
3. Department of Energy Technology, Royal Institute of Technology (KTH), Stockholm 10044, Sweden