Interfacial engineering of worm-shaped palladium nanocrystals anchored on polyelectrolyte-modified MXene nanosheets for highly efficient methanol oxidation

The development of high-efficiency methanol oxidation electrocatalysts with acceptable costs is central to the practical use of direct methanol fuel cell. In this work, a convenient interfacial engineering strategy is developed to the design and construction of quasi-one-dimensional worm-shaped palladium nanocrystals strongly coupled with positively-charged polyelectrolyte-modified Ti3C2Tx MXene (Pd NWs/PDDAMX) via the direct electrostatic attractions. Because of the intriguing structural features including ultrathin-sheet nature, homogeneous Pd dispersion, numerous grain boundaries, strong electronic interaction, and high metallic conductivity, the as-fabricated Pd NWs/PDDA-MX hybrid shows superior electrocatalytic performance with a large electrochemically active surface area of 105.3 m(2) g(-1), a high mass activity of 1526.5 mA mg(-1), and reliable long-term durability towards alkaline methanol oxidation reaction, far outperforming the commercial Pd nanoparticle/carbon catalysts. Density functional theory calculation further demonstrate that there are strong electronic interactions in the Pd nanoworm/Ti(3)C(2)T(x )model with a depressed CO adsorption energy, thereby guaranteeing a stable interfacial contact as well as strong antitoxic ability. (C) 2022 Elsevier Inc. All rights reserved.

Automated summary

In this study, a convenient interfacial engineering strategy was developed to construct worm-shaped palladium nanocrystals strongly coupled with positively-charged polyelectrolyte-modified MXene, resulting in a superior electrocatalytic performance for alkaline methanol oxidation reaction.