Abstract
Pt γ-Al 2O 3 catalysts treated in oxygen between 100 and 600 °C and in hydrogen at 500 °C were studied by uv-vis reflectance spectroscopy. The formation of different oxidized Pt surface species previously indicated by TPR studies [H. Lieske, G. Lietz, H. Spindler, and J. Völter, J. Catal. 81, 8 (1983)] was confirmed by characteristic uv-vis spectra. The results are used as the basis for a model describing the types of surface reactions and details of the platinum surface species formed in oxygen and in hydrogen, and for a model of the sintering in oxygen. The amount of soluble platinum was found to correspond with the amount of highly dispersed platinum. Hence, only surface platinum atoms are soluble.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
