Question

Hydrogen and oxygen gases are utilized as reactants for fuel cells. Hydrogen gas is oxid side to generate protons and electrons which move to the cathode side to react with oxygen to produce electricity and water as byproduct. Molecular weight: M(H2) -2 g/mol, M(O)-32 g/mol, M(H-0) - 18 g/mol. Detailed reactions in each side are described below: ized in the anode (-) side: | (+) side: Cell: H2 → 2H+ + 2e- E" 0.00V 202 + 2H+ + 2e-→ H2O Eo = 1.23V Eeu 1.23V Now the fuel cell is operating at 1 A condition, calculate 1) molar rate of H2 consumed, 2) molar rate of O2 consumed, and 3) rate of water generation at the cathode in g/hr. [Hint: use Faraday's equation] If 20-cell fuel cell stack is operating steadily in series with 50 cm2 active area (i.e. reaction area) per electrode, with a current density of 0.8 A/cm2. Fuel cell nominal voltage is 0.7 V per cell. 4) Total water production rate in g/hr tead of O2, what should be the molar supply rate of air to operate the cell at this condition? Hint: air consists of 21% O2 and 79% N2. Acho 6) Stack voltage and electrical power output? (Power-rot)

Answer 1

mole (n 1 = ïxt fuel cell VoHuge 0.7x20