Stable electrolysis of ammonia on platinum enhanced by methanol in non-aqueous electrolyte for an in-situ hydrogen production

• An electrolyte modification strategy to suppress the poisoning of platinum electrode was proposed. • The addition of methanol improves the activity of ammonia electrolysis. • The presence of methanol in the non-aqueous electrolyte has weakened the adsorption of N* species. Ammonia is a promising candidate as hydrogen carrier especially for hydrogen-powered vehicles. In-situ electrolysis of ammonia into hydrogen at ambient temperature will greatly promote the utilization of ammonia as energy source. Despite platinum electrode has exhibited a comparable efficiency for the electrolysis of ammonia in non-aqueous electrolyte, the current decrease rapidly due to the poisoning of electrode by nitride formed on the surface of anode. Herein, we adapted an electrolyte modification strategy to suppress the poisoning of platinum electrode. The addition of methanol into KPF 6 -DMF non-aqueous electrolyte results in an extraordinary enhancement on the electrochemical performance such as high current density and small polarization resistance, as well as more stable electrolysis of ammonia. Multi-characterization results and theoretical calculation reveal that methanol weakens the adsorption of N* species on platinum which in turn inhibits the formation of nitridation layer on the surface of platinum electrode. This finding provides an effective way to prevent platinum electrode poisoning by a rational design of the electrolyte for ammonia electrolysis.