A 2D Ba 2 N Electride for Transition Metal-Free N 2 Dissociation under Mild Conditions.

N 2 activation is a key step in the industrial synthesis of ammonia and other high-value-added N-containing chemicals, and typically is heavily reliant on transition metal (TM) sites as active centers to reduce the large activation energy barrier for N 2 dissociation. In the present work, we report that a 2D electride of Ba 2 N with anionic electrons in the interlayer spacings works efficiently for TM-free N 2 dissociation under mild conditions. The interlayer electrons significantly boost N 2 dissociation with a very small activation energy of 35 kJ mol -1 , as confirmed by the N 2 isotopic exchange reaction. The reaction of anionic electrons with N 2 molecules stabilizes (N 2 ) 2- anions, the so-called diazenide, in the large interlayer space (∼4.5 Å) sandwiched by 2 cationic slabs of Ba 2 N as the main intermediate.