【摘要】 考察了不同载体负载的Pd Se Ru SiW12 催化剂对乙烯直接氧化制乙酸反应的影响 ,采用固定床微反装置评价了催化剂的性能 ,通过TPD ,TPSR和BET及吸附量测定等技术对催化剂进行了表征 .结果表明 ,不同载体负载的催化剂的活性差别较大 ;不同催化剂吸附乙烯的脱附峰分布不同 .以活性炭为载体的催化剂 ,乙烯主要以物理吸附的形式存在 ,低温下即大量脱附 .以MCM 2 2为载体的催化剂 ,乙烯主要吸附在强吸附活性中心上 ,在高温下才能脱附 .以SiO2 为载体的催化剂 ,对乙烯具有适宜的吸附强度 ,有利于乙酸的生成 ,故SiO2 是乙烯直接氧化制乙酸用催化剂的合适载体 .更多还原

【Abstract】 The effect of various supports on ethylene oxidation to acetic acid over Pd-Se-Ru-SiW 12 catalyst was investigated in a fixed-bed reactor. The catalyst samples were characterized by TPD, TPSR, BET and adsorption of C 2H 4 and O 2. The results showed that the activity of Pd-Se-Ru-SiW 12/SiO 2 and its selectivity for acetic acid were prior to those of the catalyst supported on other supports. When the activated carbon (AC) was used as a support, most of C 2H 4 was adsorbed physically and desorbed at 350 K, while when the MCM-22 was used as a support, most of C 2H 4 was adsorbed on strong active sites and desorbed at 675 K and 850 K respectively. Most of C 2H 4 was adsorbed on the moderate sites of Pd-Se-Ru-SiW 12/SiO 2 catalyst and desorbed at 423～453 K, which favored acetic acid formation during ethylene oxidation.更多还原