Pillared clays with Al and AlGa polyoxycations were prepared and characterized in order to obtain materials suitable as active components in catalysts for heavy oil cracking, evaluated using a microactivity test (MAT). DRX measurements and textural parameters at different calcination temperatures showed the highest thermal stability for the AlGa-PILC sample (d(0) (0) (1) = 17.3 Angstrom; S-BET and V micropores remained around 85% at 700 degrees C with respect to the pillared material). The AlGa sample also showed higher gas oil cracking conversion and olefin production than the Al-PILC sample.