• Arlt, T.; Lüke, W.; Kardjilov, N.; Banhart, J.; Lehnert, W.; Manke, I.: Monitoring the hydrogen distribution in poly(2,5-benzimidazole)-based (ABPBI) membranes in operating high-temperature polymer electrolyte fuel cells by using H-D contrast neutron Imaging. Journal of Power Sources 299 (2015), p. 125-129

10.1016/j.jpowsour.2015.08.094

Abstract:
Neutron imaging in combination with the deuterium contrast method was used to analyze the hydrogen distribution and exchange processes in a high-temperature polymer electrolyte fuel cell in-operando. While operating the cell at steady state conditions at 200 mA cm2 and lan/ca ¼ 2/2, changeovers of the anode feed gases between hydrogen (H2) and deuterium were analyzed by neutron radiography. Protonedeuterium exchange times and progresses were studied in-operando. The exchange of protons by deuterons proceeds much faster (approx. 108e138 s) than the exchange of deuterons by protons (approx. 144e174 s), whereby the exchange takes place first near the gas inlet while a delayed onset was observed near the outlet. We can explain this effect by the different diffusion coefficients and atomic masses of deuterium and hydrogen and the operating conditions of the cell.