Química Moderna e Aplicações

Abstrato

Effect of Temperature Synthesis on the Catalytic Performance of Zirconium Pillared Interlayered Clays for Phenol Oxidation

Mnasri-Ghnimi S and Frini-Srasra N

Zirconium pillaring solutions have been prepared at different temperatures in order to investigate their effect on the physico-chemical properties of the resulting pillared clays. It has been verifed that variation in the temperature affects the properties of the pillared clays obtained. The resulting materials exhibited basal spacings in the range of 18-19.5 A°, except for pillared interlayed clays (PILCs) prepared at a temperature ≥ 75°C, whose structure collapsed below 550°C. Improvements in specific surface area (200-250 m²g^-1) were achieved. Fixed zirconium ranges between 15.3 and 17%. Stronger Bronsted acid sites were developed into the Zr-PILCs materials, in addition to Lewis sites, even at 500°C, as indicated by the desorption of n-butylamine as a probe molecule. These acid sites were strong enough to convert phenol to CO₂ and H₂O.