Pt基负载型催化剂上不同CO吸附类型的原理探究OA

This study systematically investigated the CO adsorption behavior and electron transfer mechanism on Ptn/γ-Al2O3 catalysts using density functional theory(DFT)calculations.Combined with infrared vibrational spectroscopy(FT-IR),electron difference density(EDD)and charge decomposition analysis(CDA),the authors revealed how Pt cluster size regulated CO adsorption configuration,electron transfer,and C-O bond vibrational frequency.The results show that small Pt4 sub-nanometric clusters,due to their highly coordinated unsaturated Pt atoms,have strong d-electron feedback,resulting in full filling of CO's π* antibonding orbitals,a significant weakening of the C-O bond,and a redshift in the IR frequency.Large Pt13 sub-nanometric clusters,due to their dense structure,experience electron delocalization,weaken feedback,enhance C-O bonding,and have a blueshift in the IR frequency.The electron transfer intensity increases in linear,bridge,and multi-terminal adsorption,respectively.Bridge adsorption is most sensitive to size,with an IR blueshift of 81 cm-1 observed when the number of Pt atoms increases from 4 to 13.Multi-terminal adsorption exhibits a stable frequency due to a"saturation effect".This study establishes a comprehensive correlation among Pt size,electronic structure,adsorption properties,and infrared response,elucidating the CO adsorption mechanism on Pt-based catalysts and providing atomic-scale theoretical guidance for the design of efficient catalysts.