Heterogeneous catalysed esterification of acetic acid with isoamyl alcohol: kinetic studies

A new application for transition metal chalcogenides: WS2 catalysed esterification of carboxylic acids

“…As noted above, esterification of carboxylic acids is generally accepted to follow a Brønsted acid catalyzed mechanism, and hence it is likely that the active sites in WS 2 are the Brønsted sites observed in Figure S3 by DRIFTS. Mechanistic aspects of acetic acid esterification over heterogeneous Brønsted acid catalysts indicate that the formation of a strongly adsorbed, protonated acid intermediate is followed by rate-limiting step nucleophilic attack by the alcohol to yield a protonated carbonyl through either a single-(Eley-Rideal) [27] or double-site (Langmuir-Hinshelwood) [28,29] surface reaction. Although initial esterification rates and associated Turnover Frequencies (TOFs) decreased significantly for chain length >C6, TOFs for hexanoic and palmitic acids are almost an order of magnitude higher than those reported for WO X /ZrO 2 [22] WO X /ZrPO x [30], and mesoporous SO 4 /ZrO 2 [31], twice those of either sulfonic acid functionalised SBA-15 and KIT-6 mesoporous sílicas [23,25] or heteropolyacids [32], and only surpassed by homogeneous p-sulfonic acid calix [6]arene and p-hydroxybenzenesulfonic …”

Kinetic Study of Esterification of Acetic Acid with n-butanol and isobutanol Catalyzed by Ion Exchange Resin

“…Previous studies pointed that external diffusion does not usually control the overall rate in the reactions catalyzed by ion exchanges resin unless the agitation speed is very low or the reaction mixture is very viscous and intraparticle diffusion resistances of the reactant in the ion exchange resins are not so important [6][7][8]18]. Hence all the experiments were conducted with the ion exchange resin that was supplied by manufacture (Rohm and Hass Co.) and at a fixed 500 rpm for all the experiments.…”

Kinetics of 1-hexanol etherification on Amberlyst 70

“…Frequently, some reactant or reaction product adsorbs preferably on the catalyst surface, e.g., polar species onto sulfonic styrene/divinylbenzene (S/DVB) resins, leading to a decrease of the reaction rate. This rate-inhibiting effect of polar species on S/DVB resins is sometimes used to control selectivity to intermediate products in series reactions [8][9][10][11], however this effect is undesirable when such polar species, in particular water, are reaction products [12][13][14][15][16][17][18][19][20][21][22]. To quantify the effect of reaction medium-catalyst interaction, empirical corrections are suggested in the open literature.…”