摘要
本文研究了一价、二价、三价阳离子交换处理的蒙脱土,发现非二价阳离子,如NH_4^+、Al^(+3)可调变其化学和物理性质.脉冲法的结果说明NH_4蒙脱土作为金属Ni的载体.是良好的苯加氢催化剂,对含硫化合物、H_2O等具有抗毒能力.积分反应结果证实Ni/NH_4蒙脱土上苯加氢过程,在120～190℃范围内,产物只有环己烷,反应符合Rideal机理,测得反应活化能为50.2kJ/mol.还用差热分析、X射线衍射分析对试样蒙脱土进行了测试.
The influence of vanadium deposit on the thermal and hydrothermal stability of ultrastable Y zeolite (USY) ,Y zeolite prepared by secondary synthesis with (NH_4)_2SiF_6 (SY) and cerium ion-exchanged Y zeolite (CeHY) has been investigated by using XRD and DTA methods. The relative crystallinity and the crystal collapse temperature of all three types of zeolite decrease with increase of the amount of vanadium deposit on the zeolites. Among them vanadium-deposited SY zeolites have the least loss of crystallinity and maintain the highest crystal collapse temperatures. Steam treatment at elevated temperature will destroy the vanadium-deposited samples more severely.with 2.0% vanadium deposited a complete loss of zeolite ciystallinity is observed after steaming at 700℃for both SY and USY zeolites. CeHY zeolite impregnated with vanadium can be destroyed by steaming even at 400℃. The mechanism of vanadium poisoning of the zeolites is discussed. Experimental results demonstrate that eutectic formation of V_2O_5 with RE_2O_3 and Al_2O_3 and hydrolysis of zeolites with the presence of vanadic acid are both responsible for the destruction of the zeolite crystal,but the latter is more detrimental.
出处
《石油学报（石油加工）》
EI
CAS
CSCD
北大核心
1989年第1期55-60,共6页
Acta Petrolei Sinica(Petroleum Processing Section)
