Electrochemical production of ammonia: Nitrate reduction over novel Cu-Ni-Al metallic glass nanoparticles used as highly active and durable catalyst

It is a great challenge to design and synthesize catalysts that can regulate both adsorption and desorption processes for electrocatalytic nitrate reduction to ammonia (NRA). Herein, amorphous Cu-Ni-Al nanometallic glasses (NG) were synthesized using a facile thermal evaporation coupled Joule heating method. The Cu 50 Ni 25 Al 25 -NG exhibits remarkable Faradaic efficiency (98.81 %) and NH 3 yield-rate (211.14 μmol h −1 cm −2 ) at an outstanding positive potential of −0.15 V vs. RHE. Aluminum atoms of low work-function when intercalated at different positions in Cu 50 Ni 25 Al 25 -NG enhance both adsorption and desorption processes during NRA. The oscillatory properties of surface potential detected by Kelvin-probe force microscopy demonstrate the diversity of active sites on Cu 50 Ni 25 Al 25 -NG. Two potential-regulated reaction mechanisms in NRA on the surface of Cu 50 Ni 25 Al 25 -NG were proposed using in-situ electrochemical Raman spectra. This work provides a new method for the preparation of multi-element NG enriched with low work-function metals and a new idea for the synthesis of synergistic catalytic-sites for NRAs.