ZrO2 supports with different properties were prepared, and the hydrogenation of aqueous nitrate catalyzed by ZrO2 supported Pd-Cu bimetallic catalysts was investigated. The results showed that ZrO2 support calcined at 573 K was unstable during the preparation of the bimetallic catalyst. Increasing. calcination temperature led to the increase of particle size of ZrO2 support. In addition, using ZrO2 calcined at 973 K as the support resulted in the increase of metal particle sizes and the increased content of bimetallic ensembles at the expense of monometallic Pd. The bimetallic catalyst with ZrO2 calcined at 773 K as the Support exhibited higher catalytic activity and N-2 selectivity for the reduction of aqueous nitrate as compared to the bimetallic catalyst with ZrO2 calcined at 573 or 973 K as the Support. The activity and selectivity of ZrO2 supported bimetallic catalysts for nitrate reduction also depended on the Pd/Cu ratio. Decreasing Pd/Cu ratio led to the decrease of the amount of monometallic Pd sites and to the increase of the content of Pd-Cu ensembles. The bimetallic catalyst with Pd/Cu ratio of 4/1 showed the optimum activity and N-2 selectivity for the reduction of aqueous nitrate.