Enhanced electrocatalytic performance of TiO2 nanoparticles by Pd doping toward ammonia synthesis under ambient conditions

Abstract

The traditional Haber–Bosch process in industry to produce NH₃ leads to excessive CO₂ emissions and a large amount of energy consumption. Ambient electrochemical N₂ reduction is emerging as a green and sustainable alternative method to convert N₂ to NH₃, but is in sore need of efficient and stable electrocatalysts. Herein, we propose using Pd-doped TiO₂ nanoparticles as a high-efficiency electrocatalyst to synthesize NH₃ under ambient conditions. The Pd–TiO₂ catalyst delivers a large NH₃ yield (17.4 μg h⁻¹ mg_cat.⁻¹) and a high faradaic efficiency (12.7%) at −0.50 V versus reversible hydrogen electrode in a neutral electrolyte, outperforming most Pd- and Ti-based electrocatalysts recently reported for N₂ reduction. Most importantly, it also demonstrates extraordinary long-term electrochemical stability.