Catalytic hydrogenation of nitrates in water over a bimetallic catalyst

Bimetallic (Pd/Cu) catalysts supported on alumina, which promote the liquid-phase hydrogenation of nitrates, were synthesized using catalytic reduction and consecutive impregnation and were characterized by TEM with EDX, XRD, TPR, BET, and AAS. The catalysts prepared by catalytic reduction have very small particle sizes that are unchanged even after reduction. The two metals are located near each other, as revealed in the EDX profile. Due to the close contact between Pd and Cu, Cu is stabilized in a low oxidation state. The active sites responsible for activity and selectivity in the reduction of nitrates are discussed. These catalysts show high activity for nitrate degradation and good selectivities to nitrogen.