High performance PdxCuy bimetal catalysts with adjustable Faraday current efficiency for nitrogen fixation

Abstract

The electro-catalytic nitrogen reduction reaction (NRR) at room temperature and atmospheric pressure has great potential in NH₃ production, but the low product yield because of the low density of active sites and slow reaction kinetics greatly limits its further development. To overcome these shortcomings, a series of nano Pd_xCu_y bimetal catalysts with adjustable Pd/Cu atomic ratios were prepared and used as electrocatalysts in the NRR. The Pd_xCu_y bimetal catalysts possess large surface area and numerous active sites. In particular, due to excellent conductivity and reactivity, the Pd₃Cu bimetallic catalyst showed remarkable performance with a NH₃ yield of 22.9 μg h⁻¹ mg_cat⁻¹ and a faraday efficiency (FE) of 3.26% at an overpotential of −0.25 V, while the PdCu₃ bimetal catalyst exhibited a high FE of 15.62% and a NH₃ yield of 19.1 μg h⁻¹ mg_cat⁻¹. Moreover, even at a lower overpotential of −0.15 V, the NRR yield was far more than 10 μg h⁻¹ mg_cat⁻¹. Thus, this strategy and study for preparing bimetal catalysts with adjustable FE would be beneficial for the preparation of superior bimetal NRR catalysts.