【摘要】 HY型沸石经过400℃真空煅烧,150℃吸附吡啶,分别在150℃、200℃、250℃、300℃、350℃真空脱附,先由红外光谱测得吸附在Lewis酸（简称L酸）和Bronsted酸（简称B酸）中心的吡啶吸收峰消光度(频率分别为1453cm^-1和1543cm^-1),然后,由紫外光谱测定其吡啶含量。求得两个红外吸收峰的消光系数为:ε^L=0.095±0.005cm²/μmol,εB=0.065±0.004cm²/μmol,计算了两种酸的酸量。测定了HY沸石和超稳Y沸石表面酸的酸强度分布。HY沸石的总酸量比超稳Y高,超稳Y酸强度比HY强。稳定化过程使总酸量减小,酸强度增加。在HY沸石中,L酸酸量随煅烧温度升高而升高,B酸酸量在300℃左右煅烧时达到最大,总酸量在300—350℃煅烧时出现最大。这与HY沸石催化苯的烷基化反应转化率比较,催化活性和总酸量存在密切联系。更多还原

【Abstract】 After vacuum calcination at 400℃, HY zeolite was let to adsorb pyidine at the tem-perature of 150℃, and pyridine was desorbed in vacuum at 150, 200, 250, 300 and 350℃.At first, infrared spectrum was examined to obtain the extinctions at frequency of 1453cm^-1 and 1543 cm^-1 of the absorption bands of the adsorbed pyridine on the centers ofLewis acid （acid L） and Bronsted acid （acid B）. Then the amount of pyridine wasdetermined by means of ultra-violet spectrum. According to the test results, the extinctioncoefficients of the two infrared absorption bands turn out to be ε^L=0. 095±0. 005cm²/μmol ε^B=0.065±0.004cm²/μmolThe distribution of the surface acid intensity on HY zeolite and super-stable Y zeolite canbe obtained according to the desorption of pyridine caused by programmed increase of tem-perature. The total amount of acid on HY zeolite is higher than that on super-stable Yzeolite, while the acid intensity on super-stable Y zeolite is stronger than that on HYzeolite. The process of stabilization makes the total acid amount decrease and the acidintensity increase. The amount of acid B of zeolite calcinated at different temperatures canbe calculated from the extinction of the hydroxyl （h. f. OH） infrared absorption band at 3640cm^-1. The amount of acid L can be calculated from the adsorbed pyridine. The amountof acid L increases with the rising temperature of calcination, and the amount of acid Breaches its maximum value at 300℃ in the course of calcintion. The maximum value ofthe total amount of acid appears at 300-350℃ during calcination. In comparison withthe conversion rate of the alkylation of benzene using HY zeolite as catalyst, the totalamount of acid is closely related to the catalytic activity. The centers of both acid Band acid L have catalytic effect on the reaction.更多还原