Engineering Support and Distribution of Palladium and Tin on MXene with Modulation of the d‐Band Center for CO‐resilient Methanol Oxidation

The efficiency of direct methanol fuel cell (DMFC) is largely determined by the activity and durability of methanol oxidation reaction (MOR) catalysts. Herein, we present a CO-resilient MOR catalyst of palladium-tin nano-alloy anchored on Se-doped MXene (PdSn_0.5 /Se-Ti₃ C₂ ) via a progressive one-step electrochemical deposition strategy. MOR mass activity resulting from Pd/Se-Ti₃ C₂ catalyst (1046.2 mA mg^-1 ) is over 2-fold larger than that of Pd/Ti₃ C₂ , suggesting that the introduction of Se atoms on MXene might accelerate the reaction kinetics. PdSn_0.5 /Se-Ti₃ C₂ with Se-doping progress of MXene and the cooperated Pd-Sn sites has a superior MOR mass activity (4762.8 mA mg^-1 ), outperforming many other reported Pd-based catalysts. Both experimental results and theoretical calculation reveal that boosted electron interaction of metal crystals with Se-doped MXene and optimized distribution of Pd-Sn sites can modulate the d band center, reduce adsorption energies of CO* at Pd site and enhance OH* generation at Sn site, resulting in highly efficient removal of CO intermediates by reaction with neighboring OH species on adjacent Sn sites.