Nanoscale Engineering of Building Blocks to Synthesize a Three-Dimensional Architecture of Pd Aerogel as a Robust Self-Supporting Catalyst toward Ethanol Electrooxidation

摘要

Although plenty of research studies have extensively focused on the synthesis of electrocatalysts with diverse methods, the synthesis of a high-performance electrocatalyst by a green and efficient method has still remained a vital problem that can seriously hamper the commercialization of fuel cell technology. Metallic aerogels recently appeared as a promising state-of-the-art class of self-supported architecture electrocatalyst materials because of their great electrocatalytic activity and enhanced stability for different electrochemical reactions. By taking advantage of the nanostructure engineering and new chemical reduction reaction, a novel, simple, eco-friendly, and surfactant-free procedure for the fabrication of self-assembled Pd aerogel is presented in this paper that uses the spontaneous one-step gelation process for synthesis. In contrast with other methods, our new method presents some advantages, such as being eco-friendly, simple, and having rapid synthesis. A palladium alcogel is prepared by reducing H_(2)PdCl_(4) in ethanol utilizing C_(2)H_(5)OH/NaOH as a green reductant agent in a short time for the first time, and in the following step the palladium aerogel is obtained by supercritical drying. An extraordinary 3D nanonetwork of the Pd aerogel with large porosity is then affirmed using HRTEM, FESEM, XRD, EDX, and BET methods. Due to the profuse open interconnected pores and large inner surface areas, the Pd aerogel not only showed highly boosted electrocatalytic activity toward the ethanol oxidation reaction but also depicted much higher stability, durability, and mass activity in alkaline electrolyte than Pd/C. It is believed that the Pd aerogel prepared via a straightforward approach is an advanced candidate for applications in electrocatalysis for direct alcohol fuel cells and can create a great window of opportunity for different energy-related systems.