Au enables PdAu aerogel efficient catalysts for oxygen reduction and C2 alcohol oxidation

Abstract

Metallic aerogels (MAs) with self-supporting three-dimensional (3D) porous structures constitute a potential platform for the construction of robust catalysts. In this work, we successfully constructed 3D PdAu MAs with the optimized d-band electron of Pd and geometrical lattice expansion using a maneuverable in-situ seed-mediated strategy at room temperature. The introduction of Au accelerated the kinetics of Pd4Au3 MAs toward oxygen reduction reaction (ORR), ethylene glycol oxidation reaction (EGOR), and ethanol oxidation reaction (EOR) in alkaline electrolyte, boosting the activity and stability of Pd4Au3 MAs. The mass activities of Pd4Au3 MAs/C in ORR, EGOR and EOR were 1.74, 8.57, and 9.54 A mgPd−1, respectively, which were remarkably better than those of referenced Pd MAs/C, commercial Pt/C and Pd/C. The rotating ring-disk electrode measurement illustrated that Pd4Au3 MAs/C achieved a 4-electron transfer process in ORR from O2 to OH−. In-situ Fourier transform infrared spectroscopy revealed that Pd4Au3 MAs/C enabled the cleavage of the C–C bonds, thus accomplishing the C1-complete oxidation of 10-electron ethylene glycol and 12-electron ethanol. This study provides an efficient strategy to fabricate binary non-Pt alloy aerogels as high-performance multifunctional electrocatalysts for ORR, EGOR, and EOR.