p–d\nOrbital Hybridization in Pd<sub>3</sub>Sn Metallic Aerogels Boosts\nAlcohol Electrooxidation

Orbital engineering of nanomaterials has been proven\nto be a compelling\nstrategy, which stimulates the synthesis of palladium (Pd)-based nanomaterials\nwith p–d orbital hybridization and the exploration of their\nelectrocatalytic properties. Herein, Pd<sub>3</sub>Sn metallic aerogels\n(Pd<sub>3</sub>Sn MAs) with p–d orbital hybridization were\nreasonably constructed as efficient electrocatalysts for alcohol electrooxidation.\nIn particular, the mass activity and specific activity of Pd<sub>3</sub>Sn MAs for the ethylene glycol oxidation reaction are 1.69 A mg<sub>Pd</sub><sup>–1</sup> and 3.56 mA cm<sub>Pd</sub><sup>–2</sup>, respectively, superior to Pd MAs and commercial Pd/C. Meanwhile,\nbenefiting from the excellent antipoisoning properties, Pd<sub>3</sub>Sn MAs still maintain satisfactory activity after long-term durability\ntests. Moreover, the same trend can be observed in reactions such\nas the methanol oxidation reaction, the ethanol oxidation reaction,\nand the glycerol oxidation reaction. Furthermore, density functional\ntheory calculations reveal that the p–d orbital hybridization\nof Pd<sub>3</sub>Sn MAs precisely regulates the electronic structure\nand d-band center of Pd and also decreases the reaction energy barrier\nin the rate-determining step, thus reactivating the surface of Pd<sub>3</sub>Sn MAs. This study provides a broad prospect for the design\nof efficient fuel cell electrocatalysts through orbital engineering.