Synthesis of ammonia via electrochemical nitrogen reduction on high-index faceted Au nanoparticles with a high faradaic efficiency

Abstract

The electrochemical nitrogen reduction reaction (NRR) is a promising but extremely challenging approach for ammonia synthesis under ambient conditions. Herein, we report the excellent NRR performance of gold nanoparticles (AuNPs) with multiple high-index facets, prepared by a modified seed-mediated method. At −0.3 V vs. RHE and in 0.1 M Li₂SO₄ aqueous solution, the AuNPs afford the highest faradaic efficiency (FE) of 73.32% reported so far, with a remarkable ammonia generation rate of 9.22 μg h⁻¹ cm⁻². Density functional theory (DFT) calculations reveal that the high-index faceted surfaces of the AuNPs have greater preference for the adsorption of NRR intermediates (*NNH) and significantly hinder the adsorption of competing hydrogen evolution intermediates (*H).