Visible and NIR Light Assistance of the N₂ Reduction to NH₃ Catalyzed by Cs-promoted Ru Nanoparticles Supported on Strontium Titanate

Abstract

NH₃ production accounts for more than 1% of the total CO₂ emissions and is considered one of the most energy-intensive industrial processes currently (<i>T</i> > 400 °C and <i>P</i> > 80 bars). The development of atmospheric-pressure N₂ fixation to NH₃ under mild conditions is attracting much attention, especially using additional renewable energy sources. Herein, efficient photothermal NH₃ evolution in continuous flow upon visible and NIR light irradiation at near 1 Sun power using Cs-decorated strontium titanate-supported Ru nanoparticles is reported. Notably, for the optimal photocatalytic composition, a constant NH₃ rate near 3500 μmol_NH₃ g_catalyst ^-1 h^-1 was achieved for 120 h reactions, being among the highest values reported at atmospheric pressure under 1 Sun irradiation.