Modification of α-Al2O3 support by adding barium sulfate could increase the strength and water absorption of the carriers and improve the initial catalytic activity of silver supported catalysts for ethylene epoxidation, but had little effect on the initial catalytic selectivity. With the increase of barium sulfate content in the supports, the initial reaction temperature of silver catalysts was reduced. Some 'small protrusions' on the surface of the supports were formed by calcination of the introduced barium sulfate at high temperature,and the surface of the supports became accidented. The uneven surface of the catalysts restrained the migration and aggregation of silver particles and reduced the growth rate of silver particles in the catalytic reaction process, therefore the stability of silver catalysts was improved and the life of the catalysts was prolonged.%在α-Al2 O3载体中加入硫酸钡进行改性,可以提高载体的强度和吸水率,提高Ag催化剂的初始活性,对初始选择性略有影响.随着载体中硫酸钡含量的增加,银催化剂样品的初始反应温度进一步降低.引入的硫酸钡经过高温焙烧处理在载体表面形成“小突起”组织,使载体表面变得凹凸不平,抑制催化剂表面Ag粒子的迁移与聚集,降低Ag粒子在催化反应过程中的生长速率,从而改进Ag催化剂的稳定性,延长催化剂寿命.
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