Figure 3

Brunauer-Emmett-Teller (BET) nitrogen adsorption and desorption isotherms of (a) spent FCC catalyst, (b) Ti/FCC, (c) V-Ti-2/FCC, (d) V-Ti/FCC and (e) V/FCC, inset shows its pore size distribution curve. (Test condition: Nitrogen adsorption and desorption isotherm were measured using nitrogen (99.999%) and helium at liquid nitrogen baths of 77 K).