The diffusion of molecular species through nanoporous systems in microgravity conditions is of interest due to the implications of nanotechnology in aerospace technologies. Herein we present the electrochemical oxidation of ammonia at Pt nanoparticles/nano-supporting electrode systems. The decomposition of ammonia has become of critical importance since it is a common component in aqueous streams. The experiments were carried out in a parabolic flight by using different materials to test the electrooxidation of ammonia. Linear polarization curves were attained in microgravity for all materials. In general, a reduction in catalytic performance of 20-65% was observed. (C) 2012 Elsevier Ltd. All rights reserved.