Trace Doping of Pb(OH)₂ Species on PdPb Alloys Boost Highly Active and Stable Ethanol Oxidation

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.