Submonolayered Ru-modified Pd mesoporous nanosheets as multifunctional electrocatalyst for hydrogen evolution and alcohol oxidation reactions

Abstract

The structural modulation of metal-based heterostructure plays a vital role in achieving enhanced performances for highly efficient electrocatalysis. Here we design submonolayered Ru-modified Pd mesoporous nanosheets (Pd-Ru MNSs) with the exposure of both Pd and Ru active sites as well as the high atomic utilization of two-dimensional structure. The obtained Pd-Ru MNSs can act as a highly efficient multifunctional catalyst for hydrogen evolution reaction (HER) and alcohol oxidation reactions including ethylene glycol oxidation (EGOR) and ethanol oxidation (EOR), offering new opportunities towards the alcohol oxidation assisted hydrogen production. Specifically, Pd-Ru MNSs demonstrate excellent HER performance in alkaline electrolyte, requiring an overpotential of only 16 ​mV to reach 10 ​mA ​cm⁻², significantly outperforming Pd mesoporous nanosheets and commercial catalysts. Density functional theory calculations reveal that the Ru sites in Pd-Ru MNSs could facilitate the water adsorption, accelerate the water dissociation, and optimize the hydrogen desorption, leading to the superior HER activity. Pd-Ru MNSs also exhibit high mass activities of 11.19 A mg⁻¹_Pd for EGOR and 8.84 A mg⁻¹_Pd for EOR, which is 7.8 and 9.6 times than that of commercial Pd/C, respectively. The EGOR reaction pathway over Pd-Ru MNSs was further investigated by using in situ Fourier-transform infrared spectroscopy.