Control of mesoporosity in alumina

The textural properties of the alumina carrier play a major role in governi ng the performance of alumina based heterogeneous catalysts. The regulation of the pore size distribution in the support is of paramount importance in the development of a promising catalyst. The role of peptising agent, comb ustible additives and binder in regulating the mesoporosity has been invest igated using high pressure mercury porosimetry. Control of pole size in 18- 50 Angstrom radii range can be achieved by peptising alumina monohydrate (b oehmite) by 1.5% nitric acid. Additives like polyvinyl alcohol and polyethy lene glycol have broadened the mesopores while carbon black has drastically increased pores in 50-100 Angstrom range. Addition of 10% calcined alumina as binder has been found suitable to maintain pores < 50 Angstrom radii.