Role of Nanoporous Al<sub>2</sub>O<sub>3</sub> as Matrix for Catalytic Cracking

Nanoporous (np; 5-50 nm in pore diameter) Al2O3 was investigated as a matrix for a fluid catalytic cracking (FCC) catalyst as either a binder or a catalytic site using model compounds as feedstock to achieve not only high activity, but also less coking. The binder characteristics of np Al2O3 matrix were expected to increase the mechanical strength and hydrothermal resistance of the catalyst, because np Al2O3 from unimodal and non-aggregated boehmite sols has better mechanical strength than np Al2O3 from aggregated boehmite gels and can protect the zeolite component from hydrothermal degradation during catalyst regeneration more than np SiO2. Application of np Al2O3 with controlled crystallite and pore sizes as an active matrix for catalytic cracking resulted in less coking, which indicated that np Al2O3 has an important role as a pre-cracking agent. A np Al2O3 matrix with a pore size diameter of ca. 11-15 nm was found to be optimum for a catalytic cracking catalyst.