The selective reduction of NO3- to N-2 gas using bimetallic particles of Pd/Zn. Pt/Zn, and Cu/Zn at circum-neutral pH is investigated. In the reduction of NO3- by naked iron and zinc. NH4 is the only detectable stable product with about 100% recovery of N element. After bimetal deposition, the selectivity of N-2 production is highly promoted. Of the bimetallic particles, 1 wt.% Pd/Zn shows a maximum 60% selectivity, much higher than those of Cu/Zn and Pt/Zn. The significant effects of Pd content, solution pH. and dissolved oxygen on the selectivity for N-2 suggest that the reduction of NO3- to N-2 is cathodically controlled, at which the N-2 produced was increases with increased concentration of adsorbed atomic hydrogen at the surface. (C) 2011 Elsevier B.V. All rights reserved.