Insights into defective TiO in electrocatalytic N reduction: combining theoretical and experimental studies

Artificial N 2 fixation via the Haber-Bosch process requires high temperature and high pressure at the expense of CO 2 release. Electrochemical NH 3 synthesis is emerging as an environmentally friendly alternative that operates under ambient conditions, calling for electrocatalysts with efficient N 2 reduction reaction (NRR) performance. In this paper, we experimentally and theoretically prove that defective TiO 2 on Ti mesh (d-TiO 2 /TM) acts as an electrocatalyst for the NRR. In 0.1 M HCl, d-TiO 2 /TM achieves a much higher NH 3 yield of 1.24 × 10 −10 mol s −1 cm −2 and FE of 9.17% at −0.15 V ( versus reversible hydrogen electrode) than pristine TiO 2 (NH 3 yield: 0.17 × 10 −10 mol s −1 cm −2 ; FE: 0.95%). Notably, d-TiO 2 /TM also shows great electrochemical stability and durability. Theoretical investigation further reveals the possible catalytic mechanism involved. Defective TiO 2 acts as an effective electrocatalyst for N 2 -to-NH 3 fixation with a yield of 1.24 × 10 −10 mol s −1 cm −2 and FE of 9.17% at −0.15 V.