High-Performance Bifunctional Electrocatalysts of Palladium Decoration on Carbon Nanoarchitectures for Indirect Releasing of H2 Stored in Formate

Formate has received tremendous research interest as one of the promising organic H-2 carriers to store and transport H-2 safely and economically. One paramount challenge for implementing the practical feasibility of formate as H-2 carrier is how to release H-2 at standard pressure and room temperature on demand. Herein, a proof-of-concept electrochemical strategy to indirectly release H-2 stored in formate in a controlled manner is proposed, in which formate is electrocatalytically oxidized at the alkaline anode to release electrons, which is used for H-2 generation at the acidic cathode. For this purpose, highly active bifunctional electrocatalysts with uniformly dispersed Pd nanoparticles supported on a conductive hollow dodecahedron N-doped carbon network (Pd/hd-NC), which not only shows one order of magnitude higher catalytic current density than the commercial Pd/C for alkaline formate oxidation reaction (FOR) but is comparable with the commercial Pt/C for acidic hydrogen evolution reaction (HER), are developed. A hybrid alkali/acid cell is developed using Pd/hd-NC as anode and cathode catalysts of FOR and HER, respectively; in this way, H-2 stored in formate can be indirectly released in a tunable manner, which presents significant steps forward, increasing the resiliency of formate as H-2 carrier.