Sustainable ammonia synthesis from nitrogen wet with sea water by single-step plasma catalysis

Abstract

Ammonia synthesis at ambient conditions employing intermittent distributed green sources of energy and feedstocks is globally sought to replace the centralized 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 N2 wet with seawater vapor over 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 vapor and N2. The Co/SiO2 catalyst delivered the highest ammonia synthesis rate (rNH3) of 3.7 mmol gcat-1 h-1 and energy yield of 3.2 gNH3.kW−1.h−1 at a relatively low input power of 2 W. The extraction of H atoms from H2O molecules plays an important role in the ammonia synthesis from seawater vapor. 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.