Structured fibrous carbon-based catalysts for continuous nitrate removal from natural water

[Display omitted] ▸ Bimetallic (Pd–Cu, Pd–Sn) supported nanoparticles were used for water denitrification. ▸ The catalysts were tested in both batch and continuous modes with natural water. ▸ The mesoporous CNF/SMF support allows avoiding internal diffusion limitations. ▸ (Pd–Cu) nanoparticles are probably alloyed, (Pd–Sn) nanoparticles have a core–shell structure. ▸ (Pd–Sn) catalysts are higher N2 selective as compared to (Pd–Cu) catalysts. 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 N2 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.