TiB2 thin film enabled efficient NH3 electrosynthesis at ambient conditions

Electrocatalytic N2 reduction is regarded as an attractive alternative to the industrial Haber-Bosch process for mild NH3 synthesis. However, its practical feasibility requires efficient electrocatalysts with high activity and selectivity. Herein, we first report using sputtered TiB2 film to enable superb artificial N2 reduction electrocatalysis. In 0.1 M HCl, such TiB2 seizes a great NH3 yield of 1.75 × 10−10 mol s−1 cm−2 and a high Faradaic efficiency of 11.37% at −0.30 V vs. reversible hydrogen electrode with excellent durability. Density functional theory calculations further evidence that the high activity and selectivity of TiB2 arise from the positively charged Ti atomic plane, which facilitates the adsorption, activation, and hydrogenation of N2 molecules while well suppresses the binding of H atoms.