Interactions between phenol molecules and surfaces of SiO2-Al2O3(SA), MgC and ZrO2were studied by using a temperature-programmed-desorption (TPD) method and an infrared spectroscopy. Desorption of phenol gave a single peak in the TP[ profiles of SA and ZrO2at 363 and 783 K, respectively, but complicated profiles were found on MgO. A part of the adsorbed phenol was found to decompose to benzene and water at 803 K on ZrO2, 853 K on MgO and above 873 K on SA, Desorption of water was also found below the decomposition temperatures; SA and ZrO2gave a similar profile in which the water desorption peak appeared at around 473 K. No desorption of water was found on MgO at lower temperatures for MgO evacuated at 1073 K but a new peak appeared at around 538 K for MgC evacuated at 873 K. The difference in the desorption temperatures on the three samples was explained by considering the individual surface acid-base properties and OH concentration at the surface. The relative difficulty for phenol desorption and easiness for its decomposition on ZrO2were interpreted in terms of its weak acid and weak base properties. © 1988.
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