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PdPb nanocrystals have drawn considerable attention due to their excellent catalytic properties, while their practical applications have been impeded by the severe degradation of activity, which is caused by the adsorption of intermediates (especially CO) during the operation. Herein, we first present porous PdPb alloys with the incorporation of amorphous Pb(OH) 2 species as highly active and stable electrocatalysts. Alloying Pd with Pb species is initially proposed to optimize the Pd-Pd interatomic distance and adjust the d-band center of Pd. Importantly, the amorphous Pb(OH) 2 species are beneficial to promoting the formation of OH ad and the removal of CO ad . Therefore, PdPb-Pb(OH) 2 catalysts show a mass activity of 3.18 A mg Pd -1 and keep excellent stability for the ethanol oxidation reaction (EOR). In addition, further CO stripping and a series of CO poisoning experiments indicate that PdPb-Pb(OH) 2 composites possess much better CO tolerance benefiting from the tuned electronic structure of Pd and surface incorporation of Pb(OH) 2 species., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

Even though extensive efforts have been devoted to mixing Pd nanocrystals with Ni(OH) 2 for the enhanced synergy, it remains a great challenge to incorporate nanosized Ni(OH) 2 species on the Pd electrode and reveal their synergy. Herein, we present spongelike Pd nanocrystals with the modification of amorphous Ni(OH) 2 species. The catalyst configuration is first considered by compositing Pd with Ni(OH) 2 species to optimize the Pd-Pd interatomic distance and then constructing a strongly coupled interface between Pd nanostructures and Ni(OH) 2 species. For the ethanol oxidation reaction (EOR) and the formic acid oxidation reaction (FAOR), Pd-Ni(OH) 2 composites exhibit an impressive mass activity of 4.98 and 2.65 A mg Pd -1 , respectively. Most impressively, there is no significant decrease in the EOR activity during five consecutive cycles (50 000 s). A series of CO-poisoning tests have proved that the enhanced EOR and FAOR performances involve synergy between Pd nanostructures and Ni(OH) 2 species.