Study on toluene adsorption and desorption performance of modified Pd/USY molecular sieve

 The palladium-loaded ultrastable Y molecular sieve, Pd/USY and binary and multi-component modified Pd/USY by introducing other base metals were prepared. The adsorption and desorption of toluene on the modified Pd/USY molecular sieves was characterized by N₂ physical adsorption, high resolution transmission electron microscopy (TEM), thermo gravimetric analysis (TG), chemical adsorption and X-ray diffraction (XRD). The results showed that the modified molecular sieve Pd-Ce-Zr/USY had the highest adsorption capacity, and that its saturated adsorption capacity of toluene was up to 290.7 mg/g. The high temperature desorption temperature range of toluene was 290 to 360℃. The optimum modification conditions are: 1% of palladium loading, a pH of 8, and 450℃ of calcination temperature.

Key words: ultra-stable Y (USY) zeolites; metals modification; Pd-Ce-Zr; adsorption and desorption