p–d Orbital Hybridization in Pd3Sn Metallic Aerogels Boosts Alcohol Electrooxidation

Abstract

Orbital engineering of nanomaterials has been proven to be a compelling strategy, which stimulates the synthesis of palladium (Pd)-based nanomaterials with p–d orbital hybridization and the exploration of their electrocatalytic properties. Herein, Pd₃Sn metallic aerogels (Pd₃Sn MAs) with p–d orbital hybridization were reasonably constructed as efficient electrocatalysts for alcohol electrooxidation. In particular, the mass activity and specific activity of Pd₃Sn MAs for the ethylene glycol oxidation reaction are 1.69 A mg_Pd^–1 and 3.56 mA cm_Pd^–2, respectively, superior to Pd MAs and commercial Pd/C. Meanwhile, benefiting from the excellent antipoisoning properties, Pd₃Sn MAs still maintain satisfactory activity after long-term durability tests. Moreover, the same trend can be observed in reactions such as the methanol oxidation reaction, the ethanol oxidation reaction, and the glycerol oxidation reaction. Furthermore, density functional theory calculations reveal that the p–d orbital hybridization of Pd₃Sn MAs precisely regulates the electronic structure and d-band center of Pd and also decreases the reaction energy barrier in the rate-determining step, thus reactivating the surface of Pd₃Sn MAs. This study provides a broad prospect for the design of efficient fuel cell electrocatalysts through orbital engineering.