Esterification of glycerol with acetic acid using double SO3H-functionalized ionic liquids as recoverable catalysts

Abstract

Esterification of glycerol with acetic acid was studied using a series of Brønsted acidic ionic liquids as catalysts. The results indicate that double SO 3 H-functionalized ionic liquids show high catalytic activity and fair reusability even at very low catalyst loadings, while the conventional non-functionalized ionic liquids show poor activity. The Brønsted acidity-catalytic activity relationships were also investigated and the results showed that the sequence of the catalytic activity observed in the transformation was in good agreement with the Brønsted acidity order determined by the Hammett method.

Proton transfer and esterification reactions in EMIMOAc-based acidic ionic liquids

“…Therefore, peaks of both acids are not observable. In a series of control experiments we performed headspace GC vapor pressure measurements for AIL solutions of carboxylic acids in BMIBF 4 . In these systems we do not expect proton transfer because the BF 4 À anion cannot accept protons.…”

“…In a previous report, 1 we have summarized the advancements of using acetic acid/acetate-based ionic liquids (ILs) for Fisher esterication reactions [2][3][4][5][6][7][8][9][10][11][12][13][14][15] and CO 2 absorption and electrochemical reduction. [16][17][18][19][20] Fischer esterication reactions, which are used in the chemical, food, agriculture, and petroleum industries, usually require homogeneous acidic catalysts that can be neutralized aer use.…”

Task-specific ionic liquid for the depolymerisation of starch-based industrial waste into high reducing sugars

“…The strength of the acidity depends on the position of the acidic function; -COOH or -SO 3 H function on cation possess strong intrinsic acidity [17]. SO 3 Hfunctionalised ionic liquids are strong Brønsted acids [6], [15], [18] and possess great potential as dual catalyst/solvent system and non-volatile acidic materials [19]. 1-(4-sulfobutyl)-3-methylimidazolium chloride…”

Lipophilisation of Caffeic Acid through Esterification with Propanol Using Water-tolerable Acidic Ionic Liquid as Catalyst

“…ILs functionalized with specific functionality groups have been intensively studied. Among these functionalized ILs, the SO 3 H-functionalized ILs showed higher catalytic activities than non-functionalized ILs under mild reaction conditions, because the existence of SO 3 H-functionalized groups can obviously enhance their acidities and solubilities 13,15,16 . Therefore, SO 3 H-functionalized ILs have exhibited good catalytic performance in esterification 12,13 , transesterification 14,17 and other reactions 8 .…”