Tuning Surface Potential Polarization to Enhance N 2 Affinity for Ammonia Electrosynthesis.

Electrocatalytic N 2 reduction reaction (NRR) to synthesize ammonia is a sustainable reaction that is expected to replace Haber Bosch process. Laminated Bi 2 WO 6 has great potential as an NRR electrocatalyst, however, the effective activity requires that the inert substrate is fully activated. Here, we succeeded for the first time in activating the Bi 2 WO 6 basal planes with NRR activity through Ti doping. The introduction of Ti successfully tunes the surface potential distribution and enhances the N 2 adsorption. The subsequently strong hybrid coupling of d(Ti)-p(N) orbitals fills the electronic state of N 2 antibonding molecular orbital, which greatly weakens the bonding strength of N≡N bonds. Further, in situ SR-FTIR spectrum and theoretical calculations showed that surface potential polarization enhanced the adsorption of HNN* by Bi-Ti dual-metal sites, which is beneficial for the subsequent activation hydrogenation process. The Ti-Bi 2 WO 6 nanosheets achieved 11.44% Faradaic efficiency (-0.2 V), a NH 3 yield rate of 23.14 µg mg -1 h -1 ( 15 N calibration), and satisfactory stability in 0.1 M HCl environment. The mutual assistance of theory and experiment can help understand and develop of excellent two-dimensional (2D) materials for the NRR. This article is protected by copyright. All rights reserved.