摘要
以三水氧化铝为前体,在前体混合物中加入一定量的黏结剂和不同含量的添加剂,通过挤压成型的方法制备α-氧化铝载体,利用添加剂受热分解释放气体的特点改善α-氧化铝载体的性能,并以α-氧化铝为载体制备了负载型银催化剂。采用XRD、颗粒强度测定仪、压汞仪、TG-DTA等手段研究了添加剂及其加入量对α-氧化铝载体晶型、抗压强度、孔结构、晶相转变温度的影响,利用乙烯环氧化反应评价了银催化剂的性能。实验结果表明,添加剂能抑制焙烧过程中氧化铝颗粒间的烧结团聚、改善α-氧化铝载体的抗压强度及其孔直径尺寸、改变氧化铝α相变温度、提高银催化剂的活性和选择性,通过改变添加剂的含量可进一步优化α-氧化铝载体和银催化剂的性能。
α-Alumina was synthesized from gibbsite precursor with binder and additive through extrusion process, and was used in preparing supported silver catalysts for the epoxidation of ethylene to ethylene oxide. The a-alumina was modified with gases released from the additive by its decomposition. The modified supports were characterized by means of XRD, strength analyzer, mercury penetration method and TG-DTA to investigate the effect of the additive dosage on their performance. The catalytic performances of silver catalysts supported on the supports were evaluated in a micro-reactor. The results show that the addition of the additive can effectively inhibit the aggregation of a-alumina particles, improve the strength of the supports, enlarge their pore diameter and change their phase transition temperature. So the catalytic performances of the silver catalysts were improved. The performances of both a-alumina and silver catalyst can further be optimized by adjusting the additive dosage.
出处
《石油化工》
CAS
CSCD
北大核心
2013年第8期849-853,共5页
Petrochemical Technology
