Sustainable ammonia synthesis from seawater and nitrogen by single-step plasma catalysis: a step towards New England’s farmers nitrogen autonomy

Abstract

Ammonia synthesis at ambient conditions employing intermittent green sources of energy and feedstocks is globally sought to replace the Haber-Bosch (H-B) process operating at high temperature and pressure. We report herein for the first time an effective and sustainable ammonia synthesis pathway from seawater and N2 over a spherical SiO2 and M/SiO2 (M: Ag, Cu, and Co) catalysts driven by non-thermal plasma (NTP). Experimental results indicate that the presence of a catalyst is required for ammonia production from seawater and N2. The Co/SiO2 catalyst delivered the highest ammonia synthesis rate (rate NH3) of 3.7 mmol.gcat-1.h-1 and energy yield of 3.2 g-NH3.kWh-1 at a relatively low input power of 2 W. The extraction of H atom from H2O (seawater) molecules plays an important role in the ammonia synthesis from seawater. This work unfolds a novel platform for the subsequent optimization of sustainable ammonia production from endless resources such as seawater and N2 through catalytic non-thermal plasma potentially powered by renewable sources.