Dynamic CoOOH@Co Reconstruction Activates Laser-Decorated Pd Sites for High-Selectivity Nitrate-to-Ammonia Electrocatalysis and Zn-Nitrate Batteries

초록

In this study, we introduce a rational design of pulsed laser irradiation in liquids -synthesized Pd nanoparticle-decorated Co nanodendrites (Pd/Co NDs), exhibiting high activity and selectivity toward the nitrate reduction reaction (NO3RR). The optimized Pd/Co ND-3 electrocatalyst achieves a maximum Faradaic efficiency (FE) of 92.35% at -0.1 V vs. RHE and a maximum NH3 yield rate of 9.03 mg h-1 cm-2 at -0.4 V vs RHE during NO3RR. Combined in situ and ex situ spectroscopic analyses reveal dynamic surface reconstruction processes occurring under reaction conditions. Specifically, the Pd/Co NDs undergo structural transformation into a Pd/CoOOH@Co structure during NO3RR, where the synergistic interaction within the reconstructed Pd/CoOOH@Co NDs remarkably enhances catalytic performance, as further supported by theoretical calculations. Furthermore, a Zn-NO3 - battery using Pd/Co NDs as the cathode achieves an open-circuit voltage of 1.506 V and the cathodic NO3RR FE of 68.78% at a current density of 4 mA cm-2, with long-term stability over 500 h. This study highlights the importance of surface reconstructions in the Pd/CoOOH@Co ND electrocatalysis for NO3RR and the performance of the Zn-NO3 - battery, providing valuable insights for designing advanced electrocatalysts aimed at sustainable NH3 synthesis from NO3 - pollutants.

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