SYNTHESIS AND CHARACTERIZATION OF ZRO2 AS AN ACID-BASE CATALYST - DEHYDRATION-DEHYDROGENATION OF PROPAN-2-OL

Two ZrO2-based catalysts have been synthesized by thermal treatment of a gel prepared from ZrOCl2 . 8H(2)O. The effect of different preparat ion parameters on the final properties of the solids was studied. Text ural characterization was carried out from nitrogen adsorption-desorpt ion isotherms. XRD and FT-Raman spectroscopy have been used to elucida te the physical state of the catalysts. Their acid-base properties wer e studied by using temperature-programmed desorption-mass spectrometry (TPD-MS) and diffuse reflectance FTIR techniques (DRIFT), employing p yridine, 2,6-dimethylpyridine and carbon dioxide as probe molecules. B oth solids were tested for the dehydration-dehydrogenation of propan-2 -ol. The reactivity of the catalysts was studied through isotherm and temperature-programmed surface reactions (TPSR), in a flow reactor. In addition, temperature-programmed oxidation (TPO) and temperature-prog rammed desorption (TPD) experiments revealed that catalyst deactivatio n was caused by carbon deposition and irreversible adsorption of prope ne formed on the catalytic surface.