成孔剂的量对多孔氧化铝支撑体孔结构的影响

以氧化铝为骨料,淀粉及其它有机粘结剂为成孔剂制备出管状多孔氧化铝支撑体。系统地考察了成孔剂对多孔氧化铝支撑体孔结构的影响。研究表明:当支撑体中成孔剂的质量分数 <10%时,支撑体的孔隙率稳定在35%左右。当成孔剂的质量分数在 10% ~25%之间时,支撑体的孔隙率随成孔剂量的增大而显著增加。当成孔剂的质量分数>25%时,在保证支撑体完整性的前提下,支撑体的孔隙率随成孔剂量的增大变化不大,稳定在 45%左右。成孔剂质量分数的增加会使支撑体的平均孔径增大,孔径分布变宽,平均孔径与最可几孔径的差值增大。

Effect of the content of pore-forming agents on properties of macroporous alumina supports

Tubular macroporous alumina supports containing alumina powders and pore-forming agents were prepared by plastic extrusion. The influence of the content of pore-forming agents on properties of supports such as porosity, mean pore size and pore size distribution were investigated. When the content of pore-forming agents in supports was less than 10%, the porosity of supports was stabled at 35%. However, the porosity of supports dramatically increased as the content of pore-forming agents in supports elevated from 10% to 25%. When the content of pore-forming agents in supports was greater than 25%, the porosity of supports varied slightly and was maintained at 45%. To avoid the pinholes and the cracks in the tubular alumina macroporous supports, the content of pore-forming agents in supports should not be exceed 25%. As for the pore size of supports, the mean pore size of supports was increased with the increment of the content of pore-forming agents. Meanwhile, the pore size distribution became broader and the disparity between the mean pore size and maximum pore size increased.