TiO₂/ZnO mixed oxide catalysts, characterization by x-ray photoelectron and infrared-spectroscopy and reactions with propanol and butanol

TiO₂/ZnO mixed oxide catalysts, prepared by hydrolysis of chlorides, were characterized by X-ray photoelectron and infrared spectroscopy as well as by catalytic elimination reactions of propanol and butanol. XPS measurements suggest one phase present in all oxides (ZnTiO₃), another only in oxides with 64 and 95 mole % ZnO. This unidentified phase is rather rich in ZnO, has oxygen of very high binding energy (Ols = 533 eV) and decomposes (or is modified) at temperatures above 500° C. I.r. adsorbate spectra of pyridine indicate that Ti⁴⁺ cations are mainly present on the surface of the ZnTiO₃ phase, Zn²⁺ on the surface of the other. The changes in product distribution of elimination reactions are discussed in terms of varying acid - base properties.