WEB Parallelizing electrocatalytic nitrogen reduction reaction for enhanced ammonia evolution at vanadium oxide-nitride boundaryThursday (24.09.2020) 09:15 - 09:30 F: Functional Materials, Surfaces, and Devices 1 Part of:
The electrochemical nitrogen (N2) fixation under mild conditions via N2 reduction reaction (NRR) to produce ammonia (NH3) is an attractive green synthesis to replace the widely harnessed Haber-Bosch process. This work emphasizes the concept of parallelized NRR reaction on multi-phase vanadium oxide-nitride (V2O3/VN) hybrids, as a prospective strategy to promote highly efficient NH3 production. Within the alternating mechanism, our density functional theory (DFT) results elucidate that the surface of the VN phase can form N2H4* intermediate spontaneously due to the favourable energy downhill reaction pathways. Simultaneously, V2O3 has energy downhill to form NH2* intermediate for the N2 reduction path of N2H4* → NH2*+NH3(g). Due to the abrupt concentration gradients in VN - V2O3 phase boundaries, the adsorbed intermediates, N2H4* and NH2*, are expected to be actively exchanged across the boundaries of VN and V2O3. Thus, the reactions of NRR are estimated to be parallelized, promoting the high-efficiency ammonia production. The rationally designed V2O3/VN hybrids demonstrate outstanding catalytic performance with a high NH3 yield rate of 18.36 µmol h-1 cm-2 and faradaic efficiency of 26.62% under ambient conditions. The introduction of oxides/nitrides multi-phases in a transition metal-based electrocatalyst can be a promising approach to achieve an alternative N2 fixation.