2000 Volume 108 Issue 1263 Pages 960-965
Polyhydroxoaluminum (PHA) solutions produced transparent gels on drying. These gels were transformed into activated aluminas upon heating. To obtain activated alumina having uniform pores, various amounts of tetramethylammonium chloride (TM) were added to the PHA solutions followed by drying to form PHA-TM composite gels. The γ-alumina obtained from the composite gels having ≥30% TM content showed a sharp monomodal pore size distribution in the range of 3 to 4nm, depending on the heating temperature in the range of 400 to 900°C. The γ-alumina gave the highest pore volume of 0.25cm3·g-1 at 400°C. On the other hand, the γ-aluminas obtained from the composite gels having TM content below 20% showed a bimodal pore size distribution in the range from 3 to 8nm. These results indicate that pore sizes of γ-alumina can be precisely controlled by the heating temperature for composite gels having ≥30% TM content.
