Data are presented for the transport of NH3 from the anode to the cathode for various inlet conditions in a N-2/N-2 laboratory-scale fuel cell at open circuit voltage (OCV). The data were obtained with a material balance technique, which uses an ion selective electrode (ISE) to determine the concentration of ammonium ions. The results show that ammonia did not move across the membrane when the feed to both electrodes was dry. However, with humidified feeds on either side, the ammonia was transported from the anode to the cathode. The data include changes in the relative humidity of the anode inlet and the flowrate on the cathode. The data support a diffusion-solubility mechanism in a N-2/N-2 system at OCV. (C) 2014 Elsevier B.V. All rights reserved.