View article

Qualitative FTIR has been and continues to be one of the most utilized tools in the characterization of supported metal catalysts. Quantitative FTIR has the potential to allow catalysis researchers to determine the surface concentrations of active intermediates. However, its successful application depends upon an understanding of the factors affecting integrated absorption intensities (coefficients relating IR absorbance to surface concentration). This work addresses the effect of metal particle size and temperature on the absorption intensities for CO chemisorbed on Rh/SiO₂. Absorption intensities for both linear and bridged CO surface species (A₁ and A_b) were determined by combining peak area data from IR spectra with uptake measurements obtained in gravimetric experiments. This resulted in an A₁ value of 13 (±2) and an A_b value of 42 (±6) cm/μmol. No statistically significant particle size effect has been …