Elucidation of basic properties of mesoporous alumina through the temperature-programmed desorption of carbon dioxide and heterogeneous basic catalysis of mesoporous alumina for the Knoevenagel reaction in supercritical CO2

The temperature-programmed desorption (TPD) of CO2 has been performed to elucidate the strength and the number of base sites on mesoporous alumina (mesoAl2O3). It was demonstrated that the surface of mesoAl2O3 adsorbs a much smaller amount of CO2 than those of MgO and conventional γ-Al2O3 with irregular pores, but that there exist a small number of strong base sites on mesoAl2O3 that adsorb CO2 very strongly. The CO2-TPD results clearly account for the high activity of mesoAl2O3, the low activity of γ-Al2O3, and no activity of MgO for a typical base-catalyzed reaction of the Knoevenagel reaction in supercritical CO2.

High performance of mesoporous alumina as a solid base catalyst in supercritical CO2 medium has been deeply discussed comparing the CO2-TPD results with the activities for the Knoevenagel reaction.Figure optionsDownload as PowerPoint slide