Nitrogen-doped Zn-Ni oxide nanoparticles prepared by ammonia treatment are efficient electrocata-lysts for CO2 reduction to CO.The single-phase nanos-tructures of N-Zn-Ni oxide nanoparticles exhibited high electrocatalytic CO2 reduction activity with CO Faradaic efficiency of 91.5％and partial current density of 3.2 mA·cm-2 at-0.95 V(vs.reversible hydrogen electrode\'RHE)in NaCl aqueous solution.Furthermore\'N-Zn-Ni oxides catalyst achieved CO Faradaic efficiency over 89％at-0.8 V(vs.RHE)in natural seawater\'much better than the CO2 reduction activity of benchmark Ag/C catalysts in seawater\'and demonstrated strong tolerance to several metal ion impurities with retained CO selectivity.The notable reactivity toward CO2 reduction and contamina-tion-tolerance is attributed to peculiar synergistic effect from binary Zn-Ni oxide and nitrogen doping.