Fading memory of MgAl hydrotalcites at mild rehydration conditions deteriorates their performance in aldol condensation

Potassium-modified bifunctional MgAl-SBA-15 for aldol condensation of furfural and acetone

“…12–14 Moreover, re-hydrated HTC materials enable high furfural conversion in aldol condensation between furfural and acetone at temperatures as low as 25 °C. 15,16 However, several major disadvantages have been associated with these HTC materials, including high sensitivity to ambient CO 2 , which makes recycling the catalysts difficult. 16–19…”

“…15,16 However, several major disadvantages have been associated with these HTC materials, including high sensitivity to ambient CO 2 , which makes recycling the catalysts difficult. 16–19…”

“…[12][13][14] Moreover, re-hydrated HTC materials enable high furfural conversion in aldol condensation between furfural and acetone at temperatures as low as 25 °C. 15,16 However, several major disadvantages have been associated with these HTC materials, including high sensitivity to ambient CO 2 , which makes recycling the catalysts difficult. [16][17][18][19] Porous solid acid catalysts such as zeolites of different structural kinds, including H-ZSM-5, H-MOR, H-USY and H-BEA, have also been employed for the aldol condensation of furfural with acetone.…”

“…15,16 However, several major disadvantages have been associated with these HTC materials, including high sensitivity to ambient CO 2 , which makes recycling the catalysts difficult. [16][17][18][19] Porous solid acid catalysts such as zeolites of different structural kinds, including H-ZSM-5, H-MOR, H-USY and H-BEA, have also been employed for the aldol condensation of furfural with acetone. The best catalytic behavior was observed for the H-BEA catalyst, which yielded only 30.6% FAc (furfural-acetone condensation adduct), 1.4% F 2 Ac and 6.5% (FAc) 2 (originating from dimerization of FAc and furfural, and two FAc molecules, respectively), along with 38.5% furfural conversion at 100 °C and 2 h. 20 The lower furfural conversion is due to the kinetically slower acid-catalyzed reaction pathway, in which the activation or protonation of carbonyl oxygens of both furfural and acetone are required prior to an enol formation.…”