Promising prospects for 2D d(2)-d(4) M3C2 transition metal carbides (MXenes) in N-2 capture and conversion into ammonia

Density functional theory investigations of M3C2 transition metal carbides from the d(2), d(3), and d(4) series suggest promising N-2 capture behaviour, displaying spontaneous chemisorption energies that are larger than those for the capture of CO2 and H2O in d(3) and d(4) MXenes. The chemisorbed N-2 becomes activated, promoting its catalytic conversion into NH3. The first proton-electron transfer is found to be the rate-determining step for the whole process, with an activation barrier of only 0.64 eV vs. SHE for V3C2.