The effective B acid amount of dealuminated USY(DUSY) zeolites with different silica/alumina ratios were measured by UV spectrometry with 2,6 dimethyl pyridine as adsorbentes in the presence of cyclohexane or anhydrous ethanol or tetrahydrofuran.The isomerization of α pinene was used to check the acidic catalytic properties of these zeolites.The results indicate that effective B acid amount of DUSY measured in polar anhydrous ethanol or tetrahydrofuran is lower than that of non polar cyclohexane.The effect of solution concentration of effective B acid amount of DUSY zeolites is small.As the silica/alumina ratio of catalyst increases,effective B acid amount and conversion of isomerization of α pinene all raise.
