Previously, the self-condensation of acetone is mainly studied in the gas phase under atmospheric pressure, often at high reaction temperatures above 400 °C using various solid acid catalysts such as zeolites, titania, zirconia, niobia, mesoporous aluminosilicates, and tantalum phosphate. Despite the high catalytic activity, the formation of polycondensates on the strongly acidic catalysts leads to fast catalyst deactivation due to carbonaceous deposits which remains an inherent challenge. Faba et al. showed an increase in productivity for the gas-phase conversion of acetone over a mixed catalyst bed of TiO2 and Al-MCM-41 at 250 °C but lacked the proof of long-term stability. Recently, we showed that zeolite HY is stable for the mesitylene formation in the liquid phase over several hours at 190 °C. The larger pores of zeolite Y compared to other microporous zeolites proved to be beneficial for the catalyst stability. Additionally, the liquid phase conditions allowed continuous removal of products from the catalyst bed, thus reducing carbonaceous deposits. While zeolite HY was also applicable for the aromatization of larger alkyl methyl ketones, such as 2-butanone and 2-pentanone, its overall activity was still lacking regarding a potential process development for future integration into a biorefinery. In the course of the catalyst development, combining high activity with long-term operational stability remains an ongoing problem that we sought to solve by using large pore amorphous aluminosilicates as acid catalysts.