A combined in-situ XAS-DRIFTS study unraveling adsorbate induced changes on the Pt nanoparticle structure

作者：Brieger Claudia^*; Melke Julia; van der Bosch Nils; Reinholz Uwe; Riesemeier Heinrich; Buzanich Ana Guilherme; Kayarkatte Manoj Krishna; Derr Igor; Schoekel Alexander; Roth Christina

来源：Journal of Catalysis, 2016, 339: 57-67.

DOI：10.1016/j.jcat.2016.03.034

• X-ray Absorption Spectroscopy
• DRIFTS
• XANES
• CO adsorption
• Platinum
• Strong metal support interaction
• Silica support
• Adsorbates
• Infrared spectroscopy

The adsorption behavior of Platinum nanoparticles was studied for the as-received catalyst (under inert gas), under hydrogen and CO atmosphere using our newly designed in-situ cell. X-ray Absorption Spectroscopy (XAS) and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) experiments were performed simultaneously with high data quality. Structural information and the type of adsorbate could be revealed via Extended X-ray Absorption Fine Structure (EXAFS) analysis, An X-ray Absorption Near Edge Structure analysis (Delta mu XANES) and in-situ DRIFTS. The as-received catalyst showed sub-surface oxygen and O(n-fold). Under CO atmosphere only CO(atop) was found. Reversible adsorbate induced changes of the Pt nanoparticle structure were derived from changes in the Pt-Pt coordination number and the corresponding bond distance. Under reducing conditions (H-2, CO) a significant increase in both values occurred. Temperature dependent desorption of CO revealed a gradual shift from Pt-CO to Pt-O. Reoxidation was clearly assigned to strong metal support interaction from the SiO2 support.

• 出版日期2016-7