Direct Synthesis of Pd2+‐Rich Palladene Aerogels as Bifunctional Electrocatalysts for Formic Acid Oxidation Reaction and Oxygen Reduction Reaction

In this work, we developed a direct strategy to fabricate Palladene (i. e. Palladium metallene) aerogels and propose a temperature‐dependent growth mechanism. Besides the typical three‐dimensional networks and wrinkled surface morphologies, the as‐prepared Palladene50 ${{Palladene}_{50}}$ aerogel is endowed with abundant Pd2+. The as‐prepared Palladene50 ${{Palladene}_{50}}$ aerogel exhibits an excellent mass activity in the formic acid oxidation reaction and a good half‐wave potential in the oxygen reduction reaction in comparison with Pd/C and a Pd aerogel. This work expands the range of metal aerogels from the perspective of the building block units and demonstrates a direct approach to fabricate highly promising bifunctional electrocatalysts for fuel cells. A direct strategy is developed to fabricate Pd metallene aerogels and a temperature‐dependent growth mechanism is proposed. Thanks to the 3D self‐supported network and the abundant Pd oxidation state (Pd2+), the as‐constructed Pd50 metallene aerogel is an excellent bifunctional electrocatalyst for the FAOR and the ORR.