In our previous work, zeolite HY was identified as a suitable solid acid catalyst for the efficient and stable liquid phase conversion of biomass-derived ketones to aromatics due to its larger pore size and high amount of acid sites. Catalytic activity of HY increased with temperature and at 190 °C steady-state conditions were obtained for the continuous conversion of acetone to mesitylene. However, catalyst productivity was relatively low with 3 % mesitylene yield at a weight hourly space velocity (WHSV) of 7.8 h -1 . When the reaction temperature was raised to 200 °C, the initial productivity significantly increased to about twofold but the activity steadily decreased with time-on-stream due to catalyst deactivation (Figure ). In contrast, ASA Siralox 30 is found to be very stable when converting acetone to mesitylene under similar reaction conditions (200 °C, WHSV = 7.8 h -1 ). While its activity at 200 °C is lower compared to zeolite HY, it shows a three-times increase in mesitylene yield to 4 % for 220 °C. Even at this elevated temperature, the catalyst activity remains very stable for more than 7 hours-on-stream and shows no deactivation. To understand the difference in stability of HY-5 and Siralox 30, relevant properties of the solid acid catalysts are compared in Table . The surface area of the mostly microporous zeolite HY-5 is 778 m 2 g -1 and four-times higher than the one of Siralox 30 which is completely mesoporous (Figure ). The number of surface acid sites is higher on HY-5 with 0.53 mmol g -1 compared to 0.30 mmol g -1 on Siralox 30. This results in a significantly higher activity of HY-5 at reaction temperatures below 200 °C since mesitylene activity correlates with the number of acid sites. Moreover, the strength of the acid sites on HY-5 is also greater than on Siralox 30 as evidenced by the higher temperature of the maximum NH3 desorption (Figure ).