| AVS 62nd International Symposium & Exhibition | |
| In-Situ Spectroscopy and Microscopy Focus Topic | Monday Sessions |
| Session IS+AS+SS-MoM |
| Session: | Fundamental Studies of Surface Chemistry of Single Crystal and Nanomaterials under Reaction Conditions |
| Presenter: | Maria Kipreos, University of Massachusetts, Boston |
| Authors: | M. Kipreos, University of Massachusetts, Boston M. Foster, University of Massachusetts, Boston |
| Correspondent: | Click to Email |
Traditionally, surface science employs ultra-high vacuum, cryogenic conditions and well defined crystal planes; however, heterogeneous catalysis and photocatalysis occur in ambient conditions with complex substrates composed of several crystal planes. Consequently, materials and pressure gaps exist that need to be bridged in order to better understand the surface chemistry of catalysts under reaction conditions. Metal oxide particles employed in catalysis contain a complex matrix of crystal planes, metal/oxygen bonds, metal/hydroxyl bonds, and oxide/water interactions. We utilize in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) to monitor reactions from ambient to high pressures between gaseous adsorbates (water, formic acid, and methanol) and metal oxide particles (TiO2 and ZnO, semiconductors and ZrO2,an insulator) commonly used as components of catalysts. The internal and external scattering of light that occurs in DRIFTS is well suited for analysis of reactions on the surface of metal oxide nanoparticles. Spectral shifts in frequency, peak area and width values, and absorbance values are used to interpret the structure and reactivity of the surface. Additionally, the use of Confocal Raman Spectroscopy aids in determining the structural variability in these substrates. The use of gaseous probes and these instrumental techniques provides a better understanding of the structure and reactivity of solid nanoparticles surfaces.