Direct electrochemical liquid ammonia splitting for onsite hydrogen generation under room temperature

Ammonia (NH 3 ) is seen to be promising hydrogen carrier, but its decomposition into hydrogen (H 2 ) has been plagued by high operating temperature (400‒700 °C) and long start-up time. Here, we present that directly electrochemical liquid NH 3 decomposition (ELADH) method could realize efficient onsite H 2 generation at room-temperature, whereas active and stable electrocatalytic system is challenging. Through rationally optimizing the electrolysis system with Ru catalysts, we achieved an active and durable ELADH into H 2 under ambient temperature. It was found that Ru nanoparticles (Ru NPs) with (101) facet could effectively promote the favorable N-H dissociation and hydrogen desorption, and thus accelerate the slow reaction kinetics. The as-prepared Ru NPs on nitrogen carbon exhibit lower potential of ‒1.01 V vs . NHE at ‒10 mA cm ‒2 and larger current density of ‒910 mA cm ‒2 at ‒1.47 V vs . NHE, superior to Ru single atoms and commercial Pt/C. Importantly, this system affords stable H 2 evolution under 100 h continuous electrolysis without apparent degradation, far beyond the reported catalysts. This work paves the new way of room-temperature onsite H 2 production and presents insightful understanding of the electrochemical liquid ammonia splitting process.