General Synthesis of Amorphous Pd‐Based Nanoparticles Towards Highly Efficient Nitrate‐to‐Ammonia Electrocatalysis

ABSTRACT Electrocatalytic nitrate reduction reaction (NO 3 RR) towards ammonia (NH 3 ) production is a critical process that sustainably converts hazardous nitrate to value‐added chemicals. Amorphous metal‐based nanomaterials are promising NO 3 RR catalysts owing to the abundant surface active sites, but their performance is still unsatisfactory for practical needs. We develop a robust one‐pot strategy to prepare a family of amorphous PdMP ( a ‐PdMP, M = Cu, Ni, Co, Fe, Mn, and Zn) nanoparticles with high yield, high structural stability, uniform morphology, and tunable composition. Impressively, the as‐prepared a ‐PdCoP nanoparticles show excellent electrocatalytic activity (onset potential measured at +0.3 V vs. reversed hydrogen electrode), high NH 3 selectivity, and outstanding long‐term stability (Faradaic efficiency (FE) maintained > ∼98% at 200 mA cm −2 for 200 h) in NO 3 RR. Theoretical calculations demonstrate that alloying in PdM can enhance overall electron exchange/transfer, while phosphization helps to stabilize the metal valence. Particularly, the a ‐PdCoP possesses a moderate d‐band center to avoid intermediate overbinding, meanwhile, it has the lowest work function to accelerate the electron transfer during NO 3 RR. Our work demonstrates that synergistic amorphization and phosphization of Pd alloy nanocatalysts can greatly promote their activity and durability in NO 3 RR. The universal synthesis approach provides guidance to prepare amorphous multielement nanomaterials as highly efficient electrocatalysts.