Unique superstructure of Pd-Ir aerogel as a robust three-dimensional electrocatalyst

摘要

Herein, a novel, facile, fast, and one-step strategy is introduced to synthesize a three-dimensional (3D) Pd-Ir aerogel. The Pd-Ir aerogel is synthesized by reducing metallic ions in the presence of sodium carbonate and formaldehyde, followed by CO_2 supercritical drying. Controlling the type of generated nanostructures and the reaction kinetics is adjusted by the sodium carbonate concentration. The change of sodium carbonate concentration is employed for creating an efficient anisotropic condition to create a Pd-Ir aerogel. The aerogel depicts a 3D architecture with a large porosity and an ultra-low density (0.022 g cm~(-3)). This unique architecture illustrates the exceptional electro-catalytic activity and durability owing to the following vital reasons. The 3D architecture with large open pores not only significantly facilitates the accessibility of ethanol molecules to inner active sites but also guarantees the interaction of ethanol molecules with the surface of aerogel. Furthermore, the downfall of durability observed in the Pd/C owing to corrosion can eliminate by the self-supported nature of assembled aerogel. Moreover, the presence of Ir in the structure of aerogel leads to an alteration in the electronic structure of palladium, which facilitates the electrooxidation of ethanol at a high pH environment.