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

• Published in: Journal of colloid and interface science 2022-06, Vol.616, p.781-790
• Main Authors: Xiao, Di, Jiang, Quanguo, Xu, Chenyu, Yang, Cuizhen, Yang, Lu, He, Haiyan, Huang, Huajie
• Format: Article
• Language: English
• Subjects: Electrocatalysts; Fuel cells; MXene nanosheets; Pd nanoworms; Polyelectrolyte
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2022.02.111

A convenient interfacial engineering strategy is developed to the construction of worm-shaped palladium nanocrystals strongly coupled with polyelectrolyte-modified Ti3C2Tx MXene via direct electrostatic attraction, which express exceptional electrocatalytic ability toward methanol oxidation. [Display omitted] •An interfacial engineering strategy is developed to construct Pd nanoworm/MXene catalyst.•The incorporation of PDDA ensures strong electrostatic attraction between Pd and MXene.•The resultant catalyst expresses superior catalytic performance for methanol oxidation.•DFT calculation discloses the enhanced antitoxic ability of Pd nanoworm/MXene toward CO. 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/PDDA-MX) 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 m2 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/Ti3C2Tx model with a depressed CO adsorption energy, thereby guaranteeing a stable interfacial contact as well as strong antitoxic ability.