Bimetallic (Pd-Cu, Pd-Sn) nanoparticles supported on structured fibrous carbons (activated carbon fibers and carbon nanofibers grown on sintered metal fibers) were tested in nitrate removal of natural polluted water by hydrogen (a batch and continuous mode). Dependence of the activity/selectivity on catalyst chemical composition, promoter nature and metal particle size was studied.Sn-modified Pd nanoparticles showed higher N-2 selectivity as compared to Cu-modified ones. The structured (Pd-Sn) nanoparticles supported on carbon nanofibers grown on Inconel sintered metal fibers demonstrated the best catalytic performance in an open flow reactor, providing optimal hydrodynamics properties. (C) 2012 Elsevier B.V. All rights reserved.