Cobalt nitride nanoflakes supported on Ni foam as a high-performance bifunctional catalyst for hydrogen production via urea electrolysis

摘要

Substituting low theoretical potential of the urea oxidation reaction (UOR) for the high theoretical potential of water splitting at the anode (oxygen evolution reaction) is meaningful for hydrogen energy storage and conversion. In this work, a bifunctional catalyst, cobalt nitride nanoflakes supported on Ni foam (CoN NF/NF), was synthesized for both UOR and hydrogen evolution reaction (HER). A two-electrode electrolyzer (CoN NF/NFCoN NF/NF) was constructed. To drive 100 mA/cm(2), the voltage of CoN NF/NFCoN NF/NF only 1.698 V is required, which is much lower than that of Pt/CIrO2 (1.860 V) and the current density can be maintained for 30 h. Graphic abstract A non-noble metal bifunctional catalyst, cobalt nitride nanoflakes supported on Ni foam (CoN NF/NF) was used as both anode and cathode materials for urea oxidation reaction (UOR) and hydrogen evolution reaction (HER), showing excellent catalytic activity and stability for urea electrolysis assisted hydrogen production.