Three-dimensional architecture of Pd-Ag aerogel as a unique class of inorganic modern polymers toward formic acid oxidation

Three-dimensional architectures of noble metal aerogels are considered as a unique class of inorganic modern polymers. Until now, various approaches have been published for the creation of noble metal aerogels, while their development and synthesis suffer from timeconsuming multistep procedures. Herein, we propose a simple and useful strategy for the fabrication of Pd-Ag aerogel. This method offers several advantages over other methods such as being one-pot synthesis, simplicity and fast. This three-dimensional polymer was prepared by the reduction of H2PdCl4 and AgCl in the presence of sodium carbonate by using glyoxylic acid monohydrate as a reducing agent followed by supercritical CO2 drying. The Pd–Ag aerogel was applied as a support-less catalyst for electrooxidation process of formic acid, and depicts much higher electrocatalytic activity and durability compared to the Pd/C. The higher electrocatalytic activity of the Pd-Ag aerogel compared to the Pd/C catalyst is attributed to theunique characters of this three-dimensional polymer. Mesoporous character creates a high surface area, which allows faster mass transport through the profuse pores, and macroporous character guarantees easy access of molecules to the active sites. Moreover, the self-supporting property of the Pd-Ag aerogel may prevent the loss of stability observed in Pd catalyst supported on carbon due to corrosion. We believe that the exceptional three-dimensional inorganic modern polymer fabricated by this route is powerful and promising catalysts for application in direct formic acid fuel cells (DFAFCs), which may open great opportunities for widespread applications such as catalysis, sensors, optoelectronics, electrochemical energy systems, etc.

کلیدواژه ها:

Inorganic modern polymers ، Three-dimensional architecture ، Aerogel ، One-pot synthesis method ، Formic acid oxidation