Ambient NH₃ synthesis <i>via</i> electrochemical reduction of N₂ over cubic sub-micron SnO₂ particles

Electrochemical N2-to-NH3 fixation under ambient conditions is emerging as a promising alternative to the energy-intensive and CO2-emitting Haber-Bosch process. However, this process involves difficulty in N2 activation, underlining the demand of electrocatalysts for the N2 reduction reaction (NRR). In this work, cubic sub-micron SnO2 particles on carbon cloth (SnO2/CC) are proposed as an efficient NRR electrocatalyst for ambient N2 conversion to NH3 with excellent selectivity. Electrochemical tests reveal that SnO2/CC attains a large NH3 yield of 1.47 × 10-10 mol s-1 cm-2 at -0.8 V vs. reversible hydrogen electrode (RHE) and a high Faradaic efficiency of 2.17% at -0.7 V vs. RHE in 0.1 M Na2SO4, outperforming most reported aqueous-based NRR electrocatalysts. Notably, it also shows strong electrochemical stability.