PdAg Bimetallic Nanoparticles Encapsulated in Porous Carbon Derived from UIO-66 as Electrocatalyst for Oxygen Reduction and Hydrogen Evolution Reactions

摘要

Developing dual functional electrocatalyst for both oxygen reduction reaction (ORR) and hydrogenevolution reaction (HER) is critical for promoting energy conversion efficiency in fuel cells and metal-air batteries, and produce hydrogen with high purity. Herein, PdAg bimetallic nanoparticles encapsulatedin porous carbon have been prepared and utilized as effective electrocatalysts for both ORR and HER.The surface microstructure, crystal structure, as well as electronic charge states of the bimetallic particlesencapsulated in porous carbon were studied by transmission electron microscopy (TEM), X-raydiffraction (XRD), and X-ray photoelectron spectroscopy (XPS), respectively. In the bimetallicPd x Ag 100-x (x represents the initial atomic Pd ratio in PdAg alloys) series, the Pd 50 Ag 50 sample exhibitedthe best performance, of which its ORR activity and long-term stability were superior to Pd/C in alkalinemedia along with its HER performance was comparable with Pd/C in acid solution. The study providesa reliable method for fabricating carbon substrate supported bimetallic alloys with good activity androbust stability toward ORR, HER and beyond.