Catalyst-free efficient stoichiometric synthesis of ammonia and oxygen from nitrogen and water driven by γ-ray

Abstract

Sustainable energy driven ammonia synthesis from N2 and H2O at mild conditions is desirable yet challenging. Herein, we report an efficient γ-ray radiation driven stoichiometric N2+H2O reaction to produce NH3 and O2 at room temperature with an unprecedentedly high NH3 formation rate of 70.3 μmol·h−1 without the use of catalysts, in which tannic acid is added as the ·OH scavenger to shift the water radiolysis reaction equilibrium to maximize the concentrations of eaq-, Haq+ and ·H species for the N2 reduction and meanwhile suppress the side ·OH mediated NH3 oxidation reaction. Isotope labeling, radical capture and theoretical modeling results demonstrate that NH3 is formed via the ·N2H, NHNH, ·NHNH2, NH2NH2 and ·NH2 intermediates while O2 is formed via the ·OH, H2O2 and ·OOH intermediates. Our catalyst-free γ-ray driven N2+H2O reaction provides an alternative convenient and efficient route to synthesize NH3 and O2 driven by sustainable nuclear energy.