Toward understanding of the role of Lewis acidity in aldol condensation of acetone and furfural using MOF and zeolite catalysts

Nanosized TiO2—A promising catalyst for the aldol condensation of furfural with acetone in biomass upgrading

“…Table 5 evidences that such in situ rehydration method could be really effective, since the pretreatment of calcined Mg-Al mixed oxide with aqueous acetone mixture containing 10% of water resulted in a dramatic increase in the activity of rehydrated Mg-Al hydrotalcites in aldol condensation. The observed improvement in the catalytic activity is caused by the transformation of Lewis basic sites which are present in calcined Mg-Al material to Brønsted basic sites which possess higher activity in different organic reactions in comparison with Lewis basic sites [19,23].…”

“…FAc-OH, as the initial product of aldol condensation, was easily dehydrated in the presence of strong acid centers of H-BEA to form FAc with selectivity exceeding 80%. According to [14,19], the presence (FAc) 2 , which is formed by the dimerization of FAc, is a distinctive feature of aldol condensation of furfural with acetone in the presence of acidic catalysts. Characterization of the TiO 2 materials by the TPD method using NH 3 and CO 2 indicated that these solids exhibited amphoteric character, i.e.…”

“…The essential disadvantages of such basic catalysts are their high sensitivity to ambient CO 2 , which transforms them into catalytically inactive carbonates, and the lack of reliable methods for recovering their catalytic properties after regeneration [16][17][18]. Recently, zeolites have been reported as catalysts for aldol condensation of furfural with acetone [19]. It was shown that by using zeolites the disadvantages of basic catalysts i.e.…”

“…On the other hand, their activity in aldol condensation of furfural with acetone is lower than that of hydrotalcites. Moreover, they are rapidly deactivated due to coke formation during the reaction [19]. Therefore, along with the optimization of the properties of the solid basic catalysts, attention is currently being focused on alternative solid catalysts for aldol condensation of furfural with acetone.…”

Kinetics of Aldol Condensation of Furfural with Acetone Catalyzed by 1,8-Diazabicyclo[5.4.0]undec-7-ene

“…[11] and metalorganic frameworks (MOFs) were also used to catalyze the condensation reaction between furfural and acetone [12]. The conversion of furfural and the selectivity of furfural to acetone were 38.5% and 79.5%, respectively, at 100˚C using an HBEA zeolite as catalyst.…”