Ambient Electrosynthesis of Ammonia: Electrode Porosity and Composition Engineering

Abstract

Abstract Ammonia, a key precursor for fertilizer production, convenient hydrogen carrier, and emerging clean fuel, plays a pivotal role in sustaining life on Earth. Currently, the main route for NH 3 synthesis is by the heterogeneous catalytic Haber–Bosch process (N 2 +3 H 2 →2 NH 3 ), which proceeds under extreme conditions of temperature and pressure with a very large carbon footprint. Herein we report that a pristine nitrogen‐doped nanoporous graphitic carbon membrane (NCM) can electrochemically convert N 2 into NH 3 in an acidic aqueous solution under ambient conditions. The Faradaic efficiency and rate of production of NH 3 on the NCM electrode reach 5.2 % and 0.08 g m −2 h −1 , respectively. Functionalization of the NCM with Au nanoparticles dramatically enhances these performance metrics to 22 % and 0.36 g m −2 h −1 , respectively. As this system offers the potential to be scaled to industrial levels it is highly likely that it might displace the century‐old Haber–Bosch process.