钯/炭催化剂的失活原因

The Cause of Palladium Charcoal Catalyst Deactivation

Amoco法加氢精制对苯二甲酸用含钯0.5％的钯/碳催化剂操作寿命一般为半年,每吨催化剂可处理10000吨粗制对苯二甲酸,是一个寿命较短的催化剂,本文对它失活原因进行了研究,将新鲜和使用了不同阶段的催化剂分层采样进行系统的测试。结果表明,在正常的操作条件下,失活的主要原因是钯的流失和钯晶粒的增长,杂质中毒、破碎及比表面变化等都不是失活的主要因素。

0.5％(w) palladium charcoal catalyst is used for hydropurification of terephthalic acid in Amoco process. The average life time is six months. One ton catalyst can treat 10000 tons crude terephthalic acid, the life time of catalyst is comparatively short. Systematic studies are carried out on fresh catalysts as well as those which have been used for a certain period of time and discussions made regarding the obtained results. It is found that under normal operating conditions, the chief cause of deactivation is loss of palladium and growth of palladium crystals; other causes such as poisoning, cracking and change in surface area of catalyst are not significant.