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 mgcat.-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.