活性金属浸渍方式对渣油加氢催化剂金属分散态的影响

摘要

以二次纳米自组装方法制备的贯穿孔道氧化铝为载体,采用两种浸渍方式考察活性金属负载量对催化剂分散性的影响.结果表明:随催化剂金属负载量的增加,直接浸渍法制备催化剂的孔体积从1.2 mL/g降到0.3 mL/g,比表面积由253 m2/g下降到55 m2/g；采用共浸剂改性浸渍法能大大改善催化剂的孔性质.说明以二次纳米自组装氧化铝作载体的催化剂,采用直接浸渍法,活性金属负载量的增加造成金属在小孔内部和大孔部分表面堆积,不能在载体上均匀分散,而借助共浸剂改性能达到活性金属均匀分散的目的.%Alumina carrier was prepared using secondary nano particle self-assembly method and the residue hydrotreating catalysts prepared by impregnation with different contents of active metal using two different dipping methods were investigated.It is found that the pore volume of the catalysts prepared through conventional way without complexing agent reduces from 1.2 mL/g to 0.3 mL/g and the specific surface area decreases from 253 m2/g to 55 m2/g and the active metal distribution is not even,as contrast with the impregnation results with complexing agent.Meanwhile the results indicate that the active metal is not evenly distributed on carrier with increasing amount of active metal loading,mainly concentrated and piled-up in smaller pore and on the surface of portion of the large pore.The addition of complexing agent in impregnation step can make active metal evenly distribute.