Control of mesoporosity in alumina

Abstract

The textural properties of the alumina carrier play a major role in governing 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, combustible additives and binder in regulating the mesoporosity has been investigated using high pressure mercury porosimetry. Control of pore size in 18-50Å radii range can be achieved by peptising alumina monohydrate (boehmite) by 1.5% nitric acid. Additives like polyvinyl alcohol and polyethylene glycol have broadened the mesopores while carbon black has drastically increased pores in 50-100Å range. Addition of 10% calcined alumina as binder has been found suitable to maintain pores <50 Å radii.